Oldiron440
Well-Known Member
Does the magnum block accept LA mounts?
360 Magnum
- Thread starter Bruceynz
- Start date
I don’t have exact numbers but I would say that about ½ of ALL Magnum engines have provisions for both engine mounts styles. The later ones ONLY have the new style (triangle flange) – so without mounts, they are kinda hard to fit right in.
According to this picture of his, he does have an older block that does have both engine mount provisions – so he is good!
BudW
Bruce – I like your transmission choice.
First of all, I think there is a very good probability it already has the “good” low gear set installed in it. If it somehow does not, then with the 360 – I think he is good anyway. It is the smaller engines that “need” the low gear set. As long as camshaft grind is not too radical (and also if it has the old style gear-set) then I think Bruce is good.
On the speedometer cable system. I highly prefer the screw on cable system that is currently installed into your transmission (see white arrow) for easier to perform transmission work and gear availability is more plentiful.
To bypass the cruise control and to use the screw on adapter that is currently installed, look for a Pioneer # CA-3014 or CA-3027 (should be the same part, which should come with a white clip-on connector at speedometer head).
All of the pictures of the two parts, I cannot make out the speedometer head connector well – but it should work fine.
To leave the cruise control on (my recommendation – but it is also not my decision), all you would need to do is replace the cable from cruise servo to transmission. That cable part number would be Pioneer CA-3002. This cable will have two screw on ends, with transmission nut being bigger.
Pioneer is still making these cables new and should be more reasonable price wise than trying to find an NOS cable.
There should not be any reason why you couldn’t reuse your old cable system. Just remove the small clamp on transmission end, pull the metal adapter out, and slid your old one into the same hole (I would swap over the O-ring first, though).
If it was my car, I would keep the metal screw on adapter and find either of the above cables (personally, I’d keep the cruise functioning).
This is using the newer (Magnum) style torque converter and flexplate. I prefer the starter to grind away on the flexplate, instead of the converter gear.
Also, the torque converter hub/front pump gears use a “D” design instead of a cutout design (which is both stronger and less troublesome).
Sense this shop had already installed the newer converter/pump gears, makes me also think they installed the low gear set (but not confirmed).
Bruce – I like how things are looking!
BudW
First of all, I think there is a very good probability it already has the “good” low gear set installed in it. If it somehow does not, then with the 360 – I think he is good anyway. It is the smaller engines that “need” the low gear set. As long as camshaft grind is not too radical (and also if it has the old style gear-set) then I think Bruce is good.
On the speedometer cable system. I highly prefer the screw on cable system that is currently installed into your transmission (see white arrow) for easier to perform transmission work and gear availability is more plentiful.
To bypass the cruise control and to use the screw on adapter that is currently installed, look for a Pioneer # CA-3014 or CA-3027 (should be the same part, which should come with a white clip-on connector at speedometer head).
All of the pictures of the two parts, I cannot make out the speedometer head connector well – but it should work fine.
To leave the cruise control on (my recommendation – but it is also not my decision), all you would need to do is replace the cable from cruise servo to transmission. That cable part number would be Pioneer CA-3002. This cable will have two screw on ends, with transmission nut being bigger.
Pioneer is still making these cables new and should be more reasonable price wise than trying to find an NOS cable.
There should not be any reason why you couldn’t reuse your old cable system. Just remove the small clamp on transmission end, pull the metal adapter out, and slid your old one into the same hole (I would swap over the O-ring first, though).
If it was my car, I would keep the metal screw on adapter and find either of the above cables (personally, I’d keep the cruise functioning).
This is using the newer (Magnum) style torque converter and flexplate. I prefer the starter to grind away on the flexplate, instead of the converter gear.
Also, the torque converter hub/front pump gears use a “D” design instead of a cutout design (which is both stronger and less troublesome).
Sense this shop had already installed the newer converter/pump gears, makes me also think they installed the low gear set (but not confirmed).
Bruce – I like how things are looking!
BudW
Bruceynz
Well-Known Member
Hi,
Yes all Mag blocks are far as I have read have the ears cast for the car mounts, my block is 2001. I Just bought the CA-3002 cable.
I am changing it to the cable kick down system and going to get rid of the impossible to adjust 1000 different rod combination system Chrysler used. So its all taking shape, just have a lonnnnnnnnng wait for my parts to get to NZ. I just bolted flex plate up to tqc and stuck it in place so I don't loose stuff
Automatic Transmission Details
The torque converter is a neutral balance 904 non lock up converter 2200 -2500 stall that I fitted to the mag flex plate as per magnum swaps website. I think my converter is what you would call a 340 converter.
What I worked out was if it stalled at 2300 we had 175hp on, then at 5500 we had 340hp and it changed from 1st to second the revs would drop to 3300rpm where we would have about 240hp on to pull it through to top gear but by this time your'd be going pretty fast, AJ Forms will be able to give me the exact figures and speeds.
Yes all Mag blocks are far as I have read have the ears cast for the car mounts, my block is 2001. I Just bought the CA-3002 cable.
I am changing it to the cable kick down system and going to get rid of the impossible to adjust 1000 different rod combination system Chrysler used. So its all taking shape, just have a lonnnnnnnnng wait for my parts to get to NZ. I just bolted flex plate up to tqc and stuck it in place so I don't loose stuff
Automatic Transmission DetailsThe torque converter is a neutral balance 904 non lock up converter 2200 -2500 stall that I fitted to the mag flex plate as per magnum swaps website. I think my converter is what you would call a 340 converter.
What I worked out was if it stalled at 2300 we had 175hp on, then at 5500 we had 340hp and it changed from 1st to second the revs would drop to 3300rpm where we would have about 240hp on to pull it through to top gear but by this time your'd be going pretty fast, AJ Forms will be able to give me the exact figures and speeds.
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Bruceynz
Well-Known Member
Where does all the gunk come from?
before:
after:
Still could do with a bit more cleaning! but it was like 1/4" thick of USA finest oil and dirt! Well maybe not a 1/4" but you get the idea
before:
after:
Still could do with a bit more cleaning! but it was like 1/4" thick of USA finest oil and dirt! Well maybe not a 1/4" but you get the idea
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kkritsilas
Well-Known Member
I think it is sludge build up from motor oil. It may be due to the type of oil, the use the engine saw, or lack of regular oil changes. BudW can probably tell us all stories of engines that are really sludged up. I can't really explain the whitish deposits unless it had a coolant leak at some point.
Bruceynz
Well-Known Member
its ok on the inside, is all the oil on the outside, she had a good leak going on somewhere, suspect crank seal.
The oil fairies have visited this engine and left its oil fairy dust, err buildup.
Oil leaks is typically where the outside build up comes from – but some engines seam to roll around in it. Some others seem to be as dry as a bone on outside.
I suspect not all of it is from oil leaks. Honestly, I don’t know for oil leaks would drip downward, and not leave gunk in various outside locations (ie: uphill from gravity)
I suspect it might have to do when engine cooling down in high humidity. Have you ever taken a cold bottle (of your favorite beverage) out on a humid day? Water forms on outside of bottle. The same thing happens to engines or other items as temperature differential/change happens – on humid days.
Depending on which temperature direction, water moisture will form on outside and in many cases, water droplets will form on inside (of engine).
I guess the water on outside attracts dust, maybe, and after repeated cycles it gets layered upon layer. IDK why exactly – for I don’t think it is all from oil leaks. A lot of outside engine “gunk” is dry in nature (not oily).
Inside sludge/buildup is a mostly based off of temperature difference/humidity/water condensation and vehicle trip length. Less so, it also has to do with over extended oil change intervals and getting engine oil too hot.
Engines, transmissions, differentials, etc. will all gather water moisture inside of them (outside as well) on cool down in humid weather. It happens and nothing one can stop it.
As that item gets hot again (ie: normal usage), the water will evaporate out of the fluid (engine oi, transmission fluid, differential fluid, etc.) and escape out that items vent (or breather).
I’m not sure about transmissions and differentials time, but for most people with gasoline engines, it takes about an eight (8) mile drive to get that water moisture burnt off (evaporated out).
The problem is when not all of that water moisture gets out of the engine, remnants say along and start sludge formation.
The best way to prevent engine sludge is to drive at least 8 miles once per day (or day that vehicle is driven). If drive life 4-6 miles from work, then make one trip a different way (go get stuck in rush hour traffic, or something) to reach that 8 mile distance at least once that day. Several short hops don’t count.
If you can get that 8 mile distance traveled, change the oil when manual says (or more often) and don’t let engine oil get low (which is when oil overheats)- then those people will rarely ever get sludge inside engine.
I can show you example, after example, after example, after example of people who never exceed that magical daily eight mile mark and engines are routinely nasty inside. They perform oil changes as specified and use various brands of oil and filters. I’m firmly believe oil (or filter) alone does not cause sludge. It is the un-suspecting water moisture. After I get those people to just change their driving pattern a bit, future sludge goes away.
Unrelated (sorta) – but highway vehicles hardly ever get dirty (inside) engines.
Actually, highway driven vehicles don’t get dirty engines on outside either, often.
Note: the water pump/timing cover has a coolant level mark – so that engine has been sitting somewhere, with coolant level below it should be. The water mark is visible as a horizontal line.
Air in cooling system just invites rust/corrosion inside of engine.
Also coolants anti-corrosion properties break down every two years or so – which is why most green coolant (Glycol based) is recommended to be changed every 30k miles or 2 years.
I’ve seen same difference on cooling systems on cars people change (green) coolant every 2 years - and those who do not.
Personally, I’m plagued with having a coolant leak every two years on my vehicles (water pump leak, hot water valve, heater core, cracked timing cover (road damage), etc.). Its always something . . .
BudW
Oil leaks is typically where the outside build up comes from – but some engines seam to roll around in it. Some others seem to be as dry as a bone on outside.
I suspect not all of it is from oil leaks. Honestly, I don’t know for oil leaks would drip downward, and not leave gunk in various outside locations (ie: uphill from gravity)
I suspect it might have to do when engine cooling down in high humidity. Have you ever taken a cold bottle (of your favorite beverage) out on a humid day? Water forms on outside of bottle. The same thing happens to engines or other items as temperature differential/change happens – on humid days.
Depending on which temperature direction, water moisture will form on outside and in many cases, water droplets will form on inside (of engine).
I guess the water on outside attracts dust, maybe, and after repeated cycles it gets layered upon layer. IDK why exactly – for I don’t think it is all from oil leaks. A lot of outside engine “gunk” is dry in nature (not oily).
Inside sludge/buildup is a mostly based off of temperature difference/humidity/water condensation and vehicle trip length. Less so, it also has to do with over extended oil change intervals and getting engine oil too hot.
Engines, transmissions, differentials, etc. will all gather water moisture inside of them (outside as well) on cool down in humid weather. It happens and nothing one can stop it.
As that item gets hot again (ie: normal usage), the water will evaporate out of the fluid (engine oi, transmission fluid, differential fluid, etc.) and escape out that items vent (or breather).
I’m not sure about transmissions and differentials time, but for most people with gasoline engines, it takes about an eight (8) mile drive to get that water moisture burnt off (evaporated out).
The problem is when not all of that water moisture gets out of the engine, remnants say along and start sludge formation.
The best way to prevent engine sludge is to drive at least 8 miles once per day (or day that vehicle is driven). If drive life 4-6 miles from work, then make one trip a different way (go get stuck in rush hour traffic, or something) to reach that 8 mile distance at least once that day. Several short hops don’t count.
If you can get that 8 mile distance traveled, change the oil when manual says (or more often) and don’t let engine oil get low (which is when oil overheats)- then those people will rarely ever get sludge inside engine.
I can show you example, after example, after example, after example of people who never exceed that magical daily eight mile mark and engines are routinely nasty inside. They perform oil changes as specified and use various brands of oil and filters. I’m firmly believe oil (or filter) alone does not cause sludge. It is the un-suspecting water moisture. After I get those people to just change their driving pattern a bit, future sludge goes away.
Unrelated (sorta) – but highway vehicles hardly ever get dirty (inside) engines.
Actually, highway driven vehicles don’t get dirty engines on outside either, often.
Note: the water pump/timing cover has a coolant level mark – so that engine has been sitting somewhere, with coolant level below it should be. The water mark is visible as a horizontal line.
Air in cooling system just invites rust/corrosion inside of engine.
Also coolants anti-corrosion properties break down every two years or so – which is why most green coolant (Glycol based) is recommended to be changed every 30k miles or 2 years.
I’ve seen same difference on cooling systems on cars people change (green) coolant every 2 years - and those who do not.
Personally, I’m plagued with having a coolant leak every two years on my vehicles (water pump leak, hot water valve, heater core, cracked timing cover (road damage), etc.). Its always something . . .
BudW
Bruceynz
Well-Known Member
I am going to pull the LA 360 out soon, get headers off, get the starter motor off, mock up the 360 mag and see what grinding if any I have to do to the block, the 360 Mag swap site says summit headers hit the truck engine mount bosses on drivers side, guess what headers I have Not sure where or how but starter motor may have clearance issues. When my friend comes over we are going to check the bearings for wear, I have a new oil pump to go in, new viton rear main to go in and when it arrives from USA a car oil pan and car oil pick up. I talked to the freight forwarder and my stuff is shipping out this week hopefully so should see my parts in 6 weeks they said! So also not sure but will find out when we look at bearings if we can use current ones, fit new ones or regrind. Its all exciting!
Not sure where or how but starter motor may have clearance issues. When my friend comes over we are going to check the bearings for wear, I have a new oil pump to go in, new viton rear main to go in and when it arrives from USA a car oil pan and car oil pick up. I talked to the freight forwarder and my stuff is shipping out this week hopefully so should see my parts in 6 weeks they said! So also not sure but will find out when we look at bearings if we can use current ones, fit new ones or regrind. Its all exciting!
Bruceynz
Well-Known Member
Oh well I couldn't wait so I ripped the alternator apart tonight, the bearings were bearing, the slip rings were ringed and the brushed had brushed, so it was game over, good thing I decided to rebuild it, this redish dust had got in and stuffed it!
the bearing turned worse than it looked! Hmmmmm look at all the useful crap over my workbench Now wonder I can never find my tools!
the bearing turned worse than it looked! Hmmmmm look at all the useful crap over my workbench
Now wonder I can never find my tools!AJ/FormS
Well-Known Member
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I'm watching too
Talking about cams;
at your performance level, the LSA difference of 114 vs 110 matters very little.
And as to the trans ratios, the regular 904 can be considered a close ratio, when compared to the 998/999. For a 360 this is usually a good thing. The 360 has lots of torque to get moving, so while the 11.8% ratio advantage of the 2.74 low looks attractive at first, the rpm drop on the shift demands a different cam,wider LSA cam, as the cam gets bigger. Otherwise the engine gets out of the powerband on the shift. This is more important as performance increases, and that is because sooner or later the intake duration starts to eat up low-rpm power. Not to worry at your performance level;you are many cam-sizes away from that problem.
As to cams, I'm not very excited about the one you have, but I also don't know your goals, and again;at your power level it's not a big deal. The part that I feel could be better is the ramp speed. Going from 262advertised to just 209@050 makes it a long slow ramp of 53/2 =26.5. Typically roller cams can be way faster than flat-tappets,yet yours is about 4 or 5 degrees slower than a FTH. If this continues throughout the lobe profile, then there is little to no performance in that cam. If your lobe had faster ramps like a FTH,(like maybe 22*) then it could have had about 10* more intake duration on it, and that equates to more than 1 cam size bigger, which could equate to an operating range that is 200 to 300 rpm higher, and that could equate to 15hp more at peak, with no loss in low rpm torque.
But if the roller had ramps more in line with a performance roller, (like 16 or 17*, then the cam could be nearly three sizes bigger,again with no loss in low-rpm torque. Three sizes would move the operating rpm up about 500 or 600 rpm from the current peak, and that could translate to 30 or 40 horsepower.Again with almost no loss in low-rpm torque. Then if you relax the LSA to say 112, then you would gain a bit of torque at low-rpm and broaden the powerband, just what the 904 needs.
The downside to all this is a slight loss in fuel economy at steady-state cruising.
So,to recap; Your cam is a
262/110 and 050s@209; thus has a ramp of 262 less 209 /2=........26.5
A typical FTH in this size might be 262 and 050s@218, for a ramp of 22
A typical roller should have 262 and 225@050, so a ramp of ..........18.5
The faster the ramp, the sooner the max lift and the more intake duration you can run for the same ICA, which governs the Dcr and thus the low-rpm torque production, and thus the TC stall, and thus indirectly the fuel economy of the combo.This is very important in a low-compression engine. VERY.
Looking at it from the other end;
The same ICA could be had with all of them being 262 cams, yet yours is a 209@050, the typical FTH could be a 218, and the typical performance roller could be 225. One cam size is about a 7* change,and moves the operating rpm up about 150 to 200 rpm,which is what generates the additional horsepower.
And one more illustration;a
209 is a truck cam; you can tow anything with it.
218 is a basic street cam. and
225 is just scratching at performance. The next size up,
232 would be about as big as you want to go with an automatic, and probably not available in a 262 adv, except perhaps as a race-roller. And
239 is getting to be pretty big in a stick car, and definitely not available in a 262. More than that you have to be a dedicated gearhead.
Now again, this may not matter much in your combo, as I don't know your goals. I just wanted you to be aware of what could be, and why I'm not excited about your cam. There are two good things about it tho; it will be super easy on the valve train, and lifter pump-up should be a non-issue, and 209* will make plenty of low-rpm torque to run a big hi-way gear with a modest TC.OOps, that's three/four things,lol.
And finally, who cares what excites me! That's rhetorical;you don't have to answer,lol.......
Talking about cams;
at your performance level, the LSA difference of 114 vs 110 matters very little.
And as to the trans ratios, the regular 904 can be considered a close ratio, when compared to the 998/999. For a 360 this is usually a good thing. The 360 has lots of torque to get moving, so while the 11.8% ratio advantage of the 2.74 low looks attractive at first, the rpm drop on the shift demands a different cam,wider LSA cam, as the cam gets bigger. Otherwise the engine gets out of the powerband on the shift. This is more important as performance increases, and that is because sooner or later the intake duration starts to eat up low-rpm power. Not to worry at your performance level;you are many cam-sizes away from that problem.
As to cams, I'm not very excited about the one you have, but I also don't know your goals, and again;at your power level it's not a big deal. The part that I feel could be better is the ramp speed. Going from 262advertised to just 209@050 makes it a long slow ramp of 53/2 =26.5. Typically roller cams can be way faster than flat-tappets,yet yours is about 4 or 5 degrees slower than a FTH. If this continues throughout the lobe profile, then there is little to no performance in that cam. If your lobe had faster ramps like a FTH,(like maybe 22*) then it could have had about 10* more intake duration on it, and that equates to more than 1 cam size bigger, which could equate to an operating range that is 200 to 300 rpm higher, and that could equate to 15hp more at peak, with no loss in low rpm torque.
But if the roller had ramps more in line with a performance roller, (like 16 or 17*, then the cam could be nearly three sizes bigger,again with no loss in low-rpm torque. Three sizes would move the operating rpm up about 500 or 600 rpm from the current peak, and that could translate to 30 or 40 horsepower.Again with almost no loss in low-rpm torque. Then if you relax the LSA to say 112, then you would gain a bit of torque at low-rpm and broaden the powerband, just what the 904 needs.
The downside to all this is a slight loss in fuel economy at steady-state cruising.
So,to recap; Your cam is a
262/110 and 050s@209; thus has a ramp of 262 less 209 /2=........26.5
A typical FTH in this size might be 262 and 050s@218, for a ramp of 22
A typical roller should have 262 and 225@050, so a ramp of ..........18.5
The faster the ramp, the sooner the max lift and the more intake duration you can run for the same ICA, which governs the Dcr and thus the low-rpm torque production, and thus the TC stall, and thus indirectly the fuel economy of the combo.This is very important in a low-compression engine. VERY.
Looking at it from the other end;
The same ICA could be had with all of them being 262 cams, yet yours is a 209@050, the typical FTH could be a 218, and the typical performance roller could be 225. One cam size is about a 7* change,and moves the operating rpm up about 150 to 200 rpm,which is what generates the additional horsepower.
And one more illustration;a
209 is a truck cam; you can tow anything with it.
218 is a basic street cam. and
225 is just scratching at performance. The next size up,
232 would be about as big as you want to go with an automatic, and probably not available in a 262 adv, except perhaps as a race-roller. And
239 is getting to be pretty big in a stick car, and definitely not available in a 262. More than that you have to be a dedicated gearhead.
Now again, this may not matter much in your combo, as I don't know your goals. I just wanted you to be aware of what could be, and why I'm not excited about your cam. There are two good things about it tho; it will be super easy on the valve train, and lifter pump-up should be a non-issue, and 209* will make plenty of low-rpm torque to run a big hi-way gear with a modest TC.OOps, that's three/four things,lol.
And finally, who cares what excites me! That's rhetorical;you don't have to answer,lol.......
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Bruceynz
Well-Known Member
Hi AJ Forms,
My goals are quite simple, have a engine that idles nice, have a cam that is a bit better than stock but not wild (I have a 360 LA now with a big cam and i HATE it so much I don't even drive the car)
What about my torque converter, will i benefit from a stall converter, 2200 - 2500rpm, (won't know exact stall until in car)
My goals are quite simple, have a engine that idles nice, have a cam that is a bit better than stock but not wild (I have a 360 LA now with a big cam and i HATE it so much I don't even drive the car)
What about my torque converter, will i benefit from a stall converter, 2200 - 2500rpm, (won't know exact stall until in car)
Bruceynz
Well-Known Member
I emailed the company I bought my tqc from with all my cars details - engine, cam, weight, rear end ratio, tire diameter and what ever else they asked for and they said that I would be more at 2500rpm stall which I think is is a bit high for what I want.
So I have taken my stock TQC non LU to the shop and they are going to cut it open and check it out and reset it to stall at 2000 - 2100rpm for me, I think this would be more sensible for street manners and the 360 should still have a fair bit of power and torque on there. He said when he opens up the converter he has some formulas to work with that come from a place in USA he buys parts from that he applies and work out quite accurate.
I am not building a strip car, this is going to be my daily driver, so I am doing my best to try and gain some good low down grunt! My aim is to have a nice idle, I just don't like the engine idling and it shakes the car cause cam is lopey/choppy not sure what you call it either one of those, hence the decision to buy the truck cam! Don't want a loud exhaust either.
Hoping to hear back today about the TQC, he said he would open it up today!
See You
Bruce
So I have taken my stock TQC non LU to the shop and they are going to cut it open and check it out and reset it to stall at 2000 - 2100rpm for me, I think this would be more sensible for street manners and the 360 should still have a fair bit of power and torque on there. He said when he opens up the converter he has some formulas to work with that come from a place in USA he buys parts from that he applies and work out quite accurate.
I am not building a strip car, this is going to be my daily driver, so I am doing my best to try and gain some good low down grunt! My aim is to have a nice idle, I just don't like the engine idling and it shakes the car cause cam is lopey/choppy not sure what you call it either one of those, hence the decision to buy the truck cam! Don't want a loud exhaust either.
Hoping to hear back today about the TQC, he said he would open it up today!
See You
Bruce
AJ/FormS
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There it is!
There are only three realistic and/or affordable ways to get "good low down grunt"
1)Higher stall and/or gears, and specifically a higher TM TorqueMultiplication) in the starter-gear
2)more Static compression, and
3)more Dynamic compression
For a DD, gears is not always the best Go-To.
More Static is always the BEST go-to, but sometimes, the Dynamic has to be considered first. A cam with a later closing intake (ie bigger cam), always always always, moves the power to a higher operating rpm, and with no other changes,sacrifices some low-rpm power to get it. Low rpm power is "grunt".
Increasing the Dynamic always increases the grunt. But the dynamic can only be increased to a point, and then it can create detonation issues.
So getting grunt with a particularly sized engine is a bit of a balancing act.
A lower starter gear is the number one go to. But if your funds are limited, then this too is a balancing act.
Ideally we need a 4-gear automatic. This can tighten up the power band, or broaden the application. For the same reason that the old 2-speed PowerGlide was retired, the 3-speed automatics should also be.With 4 gears, we usually get a lower first gear and an overdrive. The lower first gear combines with the current starter gear to deliver about 12% more starter-gear. But the overdrive allows a further increase in the rear gear of 45%, to get the same final-drive. This is phenomenally HUGE. The usual procedure is to split the difference; with half going each way.This gets you a lower cruising rpm and still a lot of grunt off the line.
Here is an example;
Suppose your current rear gear is 2.94 and your trans ratios are 2.45-1.45-1.00. This would make your road gears then;7.20-4.23-2.94.
Now imagine an A500 with ratios of 2.74-1.54-1.00-.68od. Again using your 2.94s, the road gears would be 8.06-4.53-2.94-2.0; there is your 12% better first gear. Plus a bonus of the 2.0cruiser gear. But say you were happy with the 2.94 final drive of the first combo. This would allow you to install 4.30s in the rear for a cruiser gear of 2.97, close enough. But the starter-gear would now be 11.78! This is a 64% increase from the original 7.2! This is like increasing your engines torque output at stall,also that same 64%, but the TM continues thru each gear. For a streeter and a DD this is waaay too much. For a 360 automatic, a starter gear of 10/1 is plenty.
So working backwards,with 3.55s,we get a starter-gear of 9.73, and a final drive of 2.41;a very nice compromise. 3.73s would also be acceptable. In fact 3.91s are about the limit. So let's see what the roadgears would be with 3.73s; I get 10.22-5.74-3.55-2.54. Compare that to your current 7.2-4.26-2.94.
The first gear has 42% more grunt, second has 35% more, and direct has 21% better, and the cruise rpm is 14% lower. And the engine remains exactly the same. What you get is more footpounds to the road in every gear, and the lower cruise rpm should translate to more mpgs.
Now I realize that this thread has just taken a serious turn.But IMO, for a DD you just can't beat TM.
A similar result can be had with an A998/999. You get the same 2.74-1.54-100 but without the OD. This will get you 12% more take-off grunt. this is like switching from 2.94s to 3.29s, without changing the cruise rpm. The 2500 stall would add it's own TM,perhaps another 10 or 12% so now you are up to over 20% additional TM. If you then increased your rear gear also say to 3.23s, another 10%; now you are over 30% better first gear grunt. This is sorta like bolting a turbo-charger onto the current combo. The 3.23s will increase your cruise rpm tho; some 10%, or perhaps 250 rpm@65mph.
All of these changes are bolt-ins.And the A998 is a non-loc,up,so it will accept your 904 TC.
The only realistic engine option that will maybe touch this, is a fast-rate-of-lift cam of the same stock .050 intake duration but with less advertised duration. Closing the intake earlier will increase the Dynamic compression ratio to a higher than stock number, giving you more cylinder pressure and hence more grunt. To be really effective this would need to be a fast roller cam. So as to your original question; you were on the right track. But it will in no wise come close to 30%.
Working with small blocks, I have done it both ways. If I had to make a choice between one or the other,(stall/gears or compression) it would be very difficult. But; I had to do the DD thing with a 318 for 5 winters in a row, and IMO, TM cannot be beat. Even a lo-C 318 with 4.30s and double overdrive is downright mean, And when you add a clutch to it, well, that's just icing on the cake.
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He has 3:23's (or 3.21's).
Bruceynz
Well-Known Member
Hey some news! My friend has giving me some Crower Enduro 1.7 Roller rockers, but I do not know how to work out if my valves will hit the pistons, at the moment the cam is .496 with 1.6 ratio so with 1.7 it would be .527" lift, is there any advantage to running them if they will not hit the pistons (I know I would need to change valve springs) the heads are Engine Quest.
Thanks
Bruce
PS - AJ/Forms sorry I haven't read what you type yet I am at work, will read it slowly and carefully tonight and take it all in with no interruptions.
Thanks
Bruce
PS - AJ/Forms sorry I haven't read what you type yet I am at work, will read it slowly and carefully tonight and take it all in with no interruptions.
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Bruceynz
Well-Known Member
AJ/FormS - Just read it all, thanks for all that info! Its all in the math! What are your thoughts on these Roller Rockers I have, will it work or am I asking for trouble?
Bruce, there is a lot on internet about checking valve to piston clearance (articles, as well as YouTube videos). Use “Engine Valve Piston Clearance” as key search words.
Most (if not all) will be using Cheby parts – but procedures are the same.
In my opinion – if I’m building an engine – not back to stock specs, I highly recommend checking these clearances first (as well as rocker arm to valve contact, pushrod to head clearance, valve spring bind, and so forth).
A lot easier to check things now, than to find out the hard way with a bunch of expensive damaged parts.
BudW
Most (if not all) will be using Cheby parts – but procedures are the same.
In my opinion – if I’m building an engine – not back to stock specs, I highly recommend checking these clearances first (as well as rocker arm to valve contact, pushrod to head clearance, valve spring bind, and so forth).
A lot easier to check things now, than to find out the hard way with a bunch of expensive damaged parts.
BudW
AJ/FormS
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It seems I got some math wrong. 3.21s would be about 9.2% better out of the gate so all math in my previous post would need to be emended to reflect that.
The 1.7s are 6% better than than the 1.6s. If starting on a new project they might be worth installing, but I wouldn't spend my time retrofitting them.
Besides the piston to valve thing, there is the geometry thing; and if you get that wrong, then either stuff wears out prematurely, or breaks. And of course all the things Bud mentioned. And one more is; will your heads, and can your heads, even take advantage of the extra lift; will your retainers smack the top of the guides.And finally, the extra .031 is a gross spec and not installed,although the difference is very small..
Dyno tests have shown that an extra 6% lift often doesn't make enough difference to get excited about, at street power levels and cams.
Additionally you may/will need springs, pushrods,possibly the guides will need to be cut or the retainers swapped out for clearance, and possibly some gaskets if the pistons have to be machined. And each cc you cut out of the piston will lose you about .13 in compression ratio. No big deal if you already have too much. But if you are already in the basement, then it's just trading hp around, and costing a lotta money to do it.
Like I said I wouldn't spend my time to retro-fit them.It could lead to a lot of work and a lotta money.
If your carb is fat, you'll probably net more power just cleaning that up.
The 1.7s are 6% better than than the 1.6s. If starting on a new project they might be worth installing, but I wouldn't spend my time retrofitting them.
Besides the piston to valve thing, there is the geometry thing; and if you get that wrong, then either stuff wears out prematurely, or breaks. And of course all the things Bud mentioned. And one more is; will your heads, and can your heads, even take advantage of the extra lift; will your retainers smack the top of the guides.And finally, the extra .031 is a gross spec and not installed,although the difference is very small..
Dyno tests have shown that an extra 6% lift often doesn't make enough difference to get excited about, at street power levels and cams.
Additionally you may/will need springs, pushrods,possibly the guides will need to be cut or the retainers swapped out for clearance, and possibly some gaskets if the pistons have to be machined. And each cc you cut out of the piston will lose you about .13 in compression ratio. No big deal if you already have too much. But if you are already in the basement, then it's just trading hp around, and costing a lotta money to do it.
Like I said I wouldn't spend my time to retro-fit them.It could lead to a lot of work and a lotta money.
If your carb is fat, you'll probably net more power just cleaning that up.
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AJ/FormS
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Bruce;
With a 904/727 the ratios are 2.45-1.45-1.00 and the splits are .59 and .69.
The 1-2 shift on your graph should occur at 6500 to drop in at .59x6500=3835.. The outgoing hp is about 280 and the incoming is a tic over that.
The 2-3 shift should be at 6150, to drop in at 4244. The outgoing power will be about 310 and the incoming will be a tic more than that.
For dragracing,I would gear it to trap at 5500 to 5700.
For the street, I would gear it to hit 65 at about 5700 in second. That would be 3.55s.
As to the TC, the 2200 might be fine if your Dcr is up. Me personally I would use a 2800; I love a good 2800 with reasonable Dcr. A 2800 will get you about 210hp on the start line, vs 150 with a 2200. That is a huge improvement of 40%! That will get the 3.55s a-humming!
210hp@2800 is about 394 ftlbs. Simple math gets about; 394x2.45x3.55=3427 ftlbs on the line. This is well into tirespin on most any A-body and street-tires.
And here's the clincher; With a 2200 and no tirespin, you would need to get up to about 23mph to match the 2800 on the line.........Shazzam!
With a 904/727 the ratios are 2.45-1.45-1.00 and the splits are .59 and .69.
The 1-2 shift on your graph should occur at 6500 to drop in at .59x6500=3835.. The outgoing hp is about 280 and the incoming is a tic over that.
The 2-3 shift should be at 6150, to drop in at 4244. The outgoing power will be about 310 and the incoming will be a tic more than that.
For dragracing,I would gear it to trap at 5500 to 5700.
For the street, I would gear it to hit 65 at about 5700 in second. That would be 3.55s.
As to the TC, the 2200 might be fine if your Dcr is up. Me personally I would use a 2800; I love a good 2800 with reasonable Dcr. A 2800 will get you about 210hp on the start line, vs 150 with a 2200. That is a huge improvement of 40%! That will get the 3.55s a-humming!
210hp@2800 is about 394 ftlbs. Simple math gets about; 394x2.45x3.55=3427 ftlbs on the line. This is well into tirespin on most any A-body and street-tires.
And here's the clincher; With a 2200 and no tirespin, you would need to get up to about 23mph to match the 2800 on the line.........Shazzam!
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