408 Stroker build who's keen to watch this one :)
- Thread starter Bruceynz
- Start date
Bruceynz
Well-Known Member
I don't want to start up the biggest debate on the planet, so this is not to wind anyone up or provoke and all out brawl,
400BB vs 408 stroker - the engine bores and strokes are vastly different, but what one hots are the best, as far as I know and I could be wrong as I don't live in muscle car land the 400 was a non performer, I am not sure if that was due to emissions laws or the combo was not good or whether it was simply the 440 was bigger so people opted for 440s.
Thanks
Bruce
400BB vs 408 stroker - the engine bores and strokes are vastly different, but what one hots are the best, as far as I know and I could be wrong as I don't live in muscle car land the 400 was a non performer, I am not sure if that was due to emissions laws or the combo was not good or whether it was simply the 440 was bigger so people opted for 440s.
Thanks
Bruce
80mirada
Well-Known Member
They can both build great power, but it comes down to heads, cam and compression. Built in the same way they will make nearly identical power, but at different RPM. The 400 is going to peak at higher RPM and the 408 will be at lower RPM. That is simply a function of piston speed
A few BB 400’s was built without (much) emissions and they ran like a scalded dog – but most BB 400’s (99%) was heavy on emissions and ran, well, a person trying to jog with ankle weights on while pushing a shopping cart. No, not a good shopping cart either – but one that a wheel vibrates which limits your speed to about 0.0063 MPH.
The 400 HP engines, like used in mid ‘70’s B-body’s, were no faster than a 360 HP (same era) engine – almost more of a joke. Now a ’72 400 HP 4-speed ran just as good as good as the ’68-71 383 HP – and some feel even better than because of the Thermoquad. The pre-emission 400 loves the RPMs and was also quick to get into the RPM’s.
An interesting fact:
318 and 340’s has a stroke of 3.31 inch (84 mm).
383 and 400 has a stroke of 3.375 inch (85.7 mm)
360 has a stroke of 3.58 inch (91 mm).
My 470 stroker (400) has a stroke of 3.915 inch (99.5 mm)
543 (440 with max stroker kit) of 4.5 inch (114.3 mm)
Back in the late ‘70’s (before stroker engines), I had a friend with a factory ’69 Super Bee 440 6-pack and he raced it constantly.
Around ’81 (or so) the original 440 developed a problem (but repairable – I don’t remember what), so he put the engine under his bench and got a 400 engine. He put some higher compression pistons (I “think” 12.5 to ones . . . maybe) and a 383 6-pack intake and raced it that way. He said he netted better times with the 400.
Visually – you couldn’t tell it was a 400.
BudW
The 400 HP engines, like used in mid ‘70’s B-body’s, were no faster than a 360 HP (same era) engine – almost more of a joke. Now a ’72 400 HP 4-speed ran just as good as good as the ’68-71 383 HP – and some feel even better than because of the Thermoquad. The pre-emission 400 loves the RPMs and was also quick to get into the RPM’s.
An interesting fact:
318 and 340’s has a stroke of 3.31 inch (84 mm).
383 and 400 has a stroke of 3.375 inch (85.7 mm)
360 has a stroke of 3.58 inch (91 mm).
My 470 stroker (400) has a stroke of 3.915 inch (99.5 mm)
543 (440 with max stroker kit) of 4.5 inch (114.3 mm)
Back in the late ‘70’s (before stroker engines), I had a friend with a factory ’69 Super Bee 440 6-pack and he raced it constantly.
Around ’81 (or so) the original 440 developed a problem (but repairable – I don’t remember what), so he put the engine under his bench and got a 400 engine. He put some higher compression pistons (I “think” 12.5 to ones . . . maybe) and a 383 6-pack intake and raced it that way. He said he netted better times with the 400.
Visually – you couldn’t tell it was a 400.
BudW
Oldiron440
Well-Known Member
Back in the mid 70s the best STOCK performance mopar was an Abody 4v 360. The Bore and long stroke worked better for emissions and was still able to maintaine decent power with low compression. The big blocks just fell on there face with emissions and leanburn. Remove the leanburn and convert the distributor, rejet the carb and give it some cam and a bb would respond with 350hp and 450 lb of torque.
But showroom stock it was the 360.
But showroom stock it was the 360.
Bruceynz
Well-Known Member
My mopar friend in NZ says I have not given my 360 a fair try before going 408, and he is right! hence me starting to get my carb sorted, you may have seen my other post, my car is going to 10.6 at about 3000rpm, so its rich as! I could be down 20 plus HP also I maybe able to get more timing into it as well, that can make more power to! I need help with carb to be honest and I don't know much about them to be honest! Current carb is 600 holley. Just your budget standard run of the mill holley!
Check out this video and don't laugh at my shoes, sorry about the video, the camera kept tipping over.
Check out this video and don't laugh at my shoes, sorry about the video, the camera kept tipping over.
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Oldiron440
Well-Known Member
Something cool for the small block coming out in January is Trick Flow is bringing out a new head. This is something that has been needed for the bigger inch small block mopars.
Bruceynz
Well-Known Member
Any suggestions on carb size, jet size, cam is 209/217 @ 50thou just under .5" lift, Engine quest heads, compression I worked out far from 9.1:1 is more like 8.8:1 we have 91ron, 95ron and 98ron, our 95/98ron is about good as your 87mon over in the USA.
When my 600 was new I took it to a carb guy and told him what I was doing, he told me that he thought it would need to be jetted up a bit for a 360 so he up the jets a couple, I also played around with the vacuum sec spring and got that working, I found out where it stumbled and then put the next strong spring in and it seems to work a treat!
When my 600 was new I took it to a carb guy and told him what I was doing, he told me that he thought it would need to be jetted up a bit for a 360 so he up the jets a couple, I also played around with the vacuum sec spring and got that working, I found out where it stumbled and then put the next strong spring in and it seems to work a treat!
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Oldiron440
Well-Known Member
I think if it's all cast iron your close but header, intake, water pump and housing your closer to 90 then if you do aluminum heads it's more like 75.
The difference in bb and sb in my opinion is that a big block picks up where the small block leaves off.
Your not going to build a NA small block with 600 ft lb of torque and 650 hp in an rpm range you can drive on the street.
The difference in bb and sb in my opinion is that a big block picks up where the small block leaves off.
Your not going to build a NA small block with 600 ft lb of torque and 650 hp in an rpm range you can drive on the street.
Bruceynz
Well-Known Member
Should I be running 600, 650, 750? What I have is a new 770 street Avenger in the garage and a used 870 street avenger!
A while ago I had some emails with a fella named Keith Dunnuck, Keith is one lucky bugger he has his own dyno, he told me had good results with a 625cfm carb on a 360!
A while ago I had some emails with a fella named Keith Dunnuck, Keith is one lucky bugger he has his own dyno, he told me had good results with a 625cfm carb on a 360!
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Oldiron440
Well-Known Member
It all depends upon the rpm range you need, if your only going to 5000 rpm your 600 should be fine plus it will give you better throttle response.
That said I think you should try a double pumper with mechanical secondarys, the throttle response will be addicting.
That said I think you should try a double pumper with mechanical secondarys, the throttle response will be addicting.
Bruceynz
Well-Known Member
what size DP and I am running an auto not stick
Oldiron440
Well-Known Member
Carb size is more important with a DP because a vacuum secondary is more forgiving. I would think a 600 to 750 depending upon the upper rpm limits of your build.
Bruceynz
Well-Known Member
this is my cam here
Hydraulic Roller Camshaft & Lifter Kit; 1992 - 2002 Chrysler 5.2L - 5.9L Magnum 1000 to 5200 Howards Cams CL770055-12 | Howards Cams
I am not sure if it is because it is a roller but its noticeable its got a cam, but its not lopey or anything, check it out, I am thinking 5500rpm?
Hydraulic Roller Camshaft & Lifter Kit; 1992 - 2002 Chrysler 5.2L - 5.9L Magnum 1000 to 5200 Howards Cams CL770055-12 | Howards Cams
I am not sure if it is because it is a roller but its noticeable its got a cam, but its not lopey or anything, check it out, I am thinking 5500rpm?
Bruceynz
Well-Known Member
Oldiron440
Well-Known Member
Having looked at your cam and it says 1000 to 5200 it's a very mild cam. The fact that your adding 50 CID to your small block makes it even smaller. You could add ten degrees of duration @ 050 for it to perform as good as it would in a 360 CID motor. Your rpm range is about 500 rpm shorter than that of a 360. You max torque and horse power will be 500 rpm sooner than that of a 360.
I would go with the 600 vacuum secondary carb.
I would go with the 600 vacuum secondary carb.
Oldiron440
Well-Known Member
I've been thinking about this and I can't not say this, your cam needs to be in the 220 @ 050 range, your giving up a great deal of usable power that you trying to gain by going with the stroker.
Oldiron440
Well-Known Member
What happened to this cam?
Bruceynz
Well-Known Member
that cam is in my garage, problem I have is the springs are not up to it, I called up EQ heads and talked to a guy there and he said the springs they use are just a little better than stock and .500" lift was about the max he would want to go in lift with those springs, the 1.64" install height is a problem.
I have in my garage a pair of Indy X heads with PEP boys titanium coated valves just standard size with mopar performance springs and retainers, the install height came in at 1.58" and the seat pressure was 160lbs, so I had to get the spring bases machined for the 1.64" and now the seat pressure is 130lbs. Good for .600" lift.
Current cam is 209 @ 50thou but thats 262 advertised, the advertised for stock cam is 249/269 at .410/.417
I have in my garage a pair of Indy X heads with PEP boys titanium coated valves just standard size with mopar performance springs and retainers, the install height came in at 1.58" and the seat pressure was 160lbs, so I had to get the spring bases machined for the 1.64" and now the seat pressure is 130lbs. Good for .600" lift.
Current cam is 209 @ 50thou but thats 262 advertised, the advertised for stock cam is 249/269 at .410/.417
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