Project Tire Fryer

[Bruceynz]

Hi Guys,

Well if you have been following me then you will know I have been playing around with a 360 into my Cordoba. Its taking me a while to realize that the low comp 360 is really a lemon. Doesn't matter what you do if you don't have comp you have a lemon!

My friend in Aussie and I have devised an evil against the grain plan to get the comp up. You guys will probably laugh at this but its worth a try!

I have bought some 318 heads, I am going to have them milled 20 thou, hope to get them at 60cc or below, (260 heads approx. 72cc) going to have the 360 1.88 intake valves installed, square up the intake ports and port match and blend the throats, this should get the comp up to at least 9.3:1

Now before you cry you are killing your air flow, yeah I agree with you! But and here it is, if you can turn the 360 to 4500rpm with 318 heads then it will go like a rocket, sure it won't make as much HP but I don't drive at 5000rpm all day, I want blistering 0-60mph times not top end of 200mph! or 1/4 miles times in the 13.Xs

The air speed with the small ports will be incredible, the off line performance should be tire frying! The compression will be up so the cam will bark into life. The thing should take off well with tire frying performance!

I am going to give up fast 1/4mile times for tire frying 0-60mph times, as this is where most of my driving is done on the street.

I have the heads in my garage, going to start the port work soon.

Anyone got any good advice or done what I am doing?

See You
Bruce

 

[Joe12459]

That actually sounds like a good combination. Of course, another good option for a low compression engine is an old school 6-71 blower sticking out the hood!

 

[slant6billy]

I'm sitting on a similar 360 build. My 360 is from a 92 ram 3/4 ton truck. TheHeads are the high flow, but it only has 8 to 1 compression. That is where the FI Tech fuel injection is key. With the FI tech unit , it acts like a blow through carb. Add a powerdyne or paxton or side vein blower system with an innercooler and now you make power

 

[brotherGood]

I've gotta ask..why not shave the block too if youre going for compression. One big factor in the compression rating being so low is because the cylinders are so deep in the bore.

 

[80mirada]

If you were to deck the block you may as well put in new pistons................actually if there is minimal ring wear a piston swap is doable with a fresh honing and new rings.

If you can get the ports close to 360 size, splitting the difference between 360 and 318, it should pull pretty damn good. The super stock guys ported 302 castings to about 90% of 360 sized and ran back cut one piece 1.88 stainless valves.

 

[Bruceynz]

you can't change 360 pistons much off stock without rebalancing the whole thing! external balance engines are a pig man!

 

[AJ/FormS]

I tell you what, I did something like that in the early 70's.
I put a complete 2bbl teener top end and cam, in/on to a junkyard 340. No machining.Shazzam! Torque out the wazoo.
I was in my early 20s and broke as could be, and all the parts came to me for services rendered; so basically,free.
I called it my big-bore teener;experimental, heehee.
But for you,you are starting with the pistons way too far down in the hole.
Personally, I think I would skip the big-valve thing, and all the port work. Actually,I think I would skip the whole teener head thing.
I would just put some gears in the back and call it done. Well maybe an A-500 too.
Adding 20% to 30% more gear,going from 2.7s to 3.5s say, or higher will get you waaay more footpounds than with your plan.If you've never had the chance to ride in a car with 3.91s say, well you are in for a surprise! Hang on,man!Top of second will be a tick over 65; so perhaps 4.10s will do it. (60x1056x4.10x1.45)/(26.5tirex3.1416) =4524 rpm. AND, 2.45x4.1=10.05 starter gear, times the TC ratio, will be right in the zone.
Swapping gears is easy,cheap, and effective. For the cost of all your proposed machining, there's more effective ways to spend that cash.And then you have to make all those machined parts play nice together.Sometimes they don't, and you have to re-machine, on account of somebody messed up. In the end your 360 might pick up a few ftlbs . Whereas a starter gear in the range of 10 or 11 to one, will absolutely annihilate the tires.Even with a lemon of a 360

I've done lots of gear swaps over the decades, and nobody ever came back,not smiling.........

In any case, whatever you decide,let us know how it works out.

 

[Bruceynz]

cars got an open 3.21:1 8.25" in it now and it can't spin the tires on take off!

 

[AJ/FormS]

There you go; 4.10s would be a 28% improvement over 3.21s. It would take a turbo to equal that,or about 460 cubes.
Either the 360 is very tired, or perhaps the TC is not working right, or the car is a real tank.

I recommend a compression test, a stall test, and weigh-scale.

 

[Bruceynz]

Gas is $8 a galon in New Zealand

 

[AJ/FormS]

Hi Guys,
I have bought some 318 heads, I am going to have them milled 20 thou, hope to get them at 60cc or below, (260 heads approx. 72cc) going to have the 360 1.88 intake valves installed, square up the intake ports and port match and blend the throats, this should get the comp up to at least 9.3:1
I want blistering 0-60mph times not top end of 200mph!
I am going to give up fast 1/4mile times for tire frying 0-60mph times, as this is where most of my driving is done on the street.
Anyone got any good advice or done what I am doing?
See You
Bruce

By your own admission,"mostly street driving".
The plus 28% torque multiplication just means minus 28% hi-way cruising rpm. So slow down. Cruise rpm at 65 with 3.21s and 26.5s is about 2600rpm. Cruising at 50 with 4.1s is also 2600. With the 4.1s the engine is way less loaded, and throttle opening will be considerably less;so fuel mileage (at 50 now) may actually go up! Higher hi-way revs costs gas, there is no arguing that. But wind resistance costs money too.
With a given engine and transmission,you cannot have it both ways; blistering acceleration and minimum fuel useage.Well you can but not with your combo.
Freshening up the 360, if it is tired, is a step in the right direction; but I think, and this is just my opinion, you need to rethink your plan.For what you are about to spend in both money and time, you can take a heck of a bite out of the cost of installing a turbo, and 2.7s. There is your blistering acceleration AND better fuel economy. Do it to a teener, and Shazzam!Either way,now you can double your low-speed torque(maybe more),do 60 at the top of first, and cruise at 65=under 2300.
But to reiterate, for a streeter;gears is the quickest,easiest,most effective way to accomplish what you are trying to achieve.
Oh yeah, here in Manitoba, gas was $1.32/liter in 2015. It has since dropped,go figure, and has been hovering around $1.00 for several months now. I re-organized my transmission years ago, and now have both 4.10 performance, and 2.76 cruising, in one box.
All that machining,and fitting, will buy a lot of gasoline.Well at $8 maybe not a lot exactly.
Bringing up the compression with pistons is by far the best idea. This will also bring up the performance, AND reduce fuel consumption. You get to keep the 3.21s until you blow 'em up peg-legging it.And the 360 heads will also do the job just fine. Closed chamber heads would be better of course.
If I had to chose just one thing,and the engine was tired, I would put Hi-comp pistons in it. BUT:If the engine was currently making140plus psi cylinder pressure, I would be putting gears in it.
If I could choose two things,it would be pistons and gears.
And if three things it would be pistons, gears, and a higher stall TC.
But in all cases, I would keep the 360 heads, AND install a SureGrip!;unless I still had cash.Then I would upgrade to closed chamber heads. But you don't need those to go 0 to 60mph,quickly.
To go 0 to 60 quickly, you just need a high power to weight ratio, and the right gearing,and traction. Your chassis weight is more or less fixed.Your engine has been selected,and it's power at the current stall-speed is more or less fixed. So that just leaves gearing.Optimize the gearing and the stall-speed and then you will have to take care of the traction issues.If you are worried about gas-mileage, buy a transmission with more gears,or another car.
Oh yeah one more thing; at $8/gallon, I would be shopping for a bicycle.Or maybe a scooter.Or taking the bus.I certainly wouldn't be looking to improve my 0 to 60 times into blistering territory.
Anyway, it's your time,your money,and your learning curve; so try to have fun while doing whatever you will do.

 

[MiradaMegacab]

3.21's and the engine combo are PERFECT for boost........
What cam do you have? A stock or wide LSA would be great......

 

[High Speed Pursuit]

Changing your rear end gear is the solution...all internal things being the same in two engines built identically in the same two model of cars, its the rear end gear difference that will propel one car to win over the other. My opinion is that when u shave the heads to raise the compression in your engine, you will increase the blowby thru your old rings, which will create more pressure on your crankcase, causing a reduction in HP at a minimum and total ring failure at the worst. I would start with the rear end, then transmission, and lastly the engine to find the acceleration you are looking for...

 

[Bruceynz]

OK I bought engine used, it has a cam in it, at a guess something a little more than a 340 manual cam, had sump off and bores looked good and could see cross hatching hone marks, has high volume oil pump, double roller timing chain, heads have after market valve springs and retainers, has edelbrock performer intake and headers, 5500rpm under load and no blue smoke out exhaust. I am using the A998 trans with lock up converter. I do have linkage problems and have ordered lokar cable, in drive it changes into second at 3500rpm and can't seem to adjust any better. My friend in oz built a 318 with 360 j heads, 30 thou off the heads with a 4 speed and 3.23 rear with a 340 cam. It was doughy down low, my engine is doughy down low! Once revs are up and I shift my trans manually it goes ok, its so bad my friend in oz thought my rear end ratio is 2.2 not 3.21, can the trans shifting manually be the problem, is it the torque converter? Advance is 34 degrees, suppose to be a performance graph on dizzy. We think its a low compression problem, cams need at least 9:1 to work, if you floor it, it can't even light up one wheel on a 3.21 open rear end. A 318 2bbl on a 3.23 can!! Something wrong! What is it?

 

[MiradaMegacab]

Forced Induction

 

[kkritsilas]

I think that the cam needs to be looked at. Do you have the cam specs? How do you know "...cams need at least 9:1 compression to work"? Factory ones don't, obviously, and most RV type cams don't, either. From your description, the cam in your car is more aggressive than the one in your friend's car. It may be too aggressive, killing cylinder pressure/dynamic compression. Do you have the stock 360 cam, or does your friend in Oz have his original cam? Maybe a swap to that cam would give you an idea of what is going on? The A998 transmission that you have seems to be "off". Have you put in a shift kit? Was the transmission working OK with your old 318? Part of the problem may have to do with the transmission cable, so you may need to wait for the Lokar one to come in.

 

[Bruceynz]

Have no cam specs, friend in Oz sold that car, only way to get cam specs is with dial gauge and degree wheel. So I would have to pull intake off and rocker gear and pop a solid lifter in and measure lift. Transmission is stock 998 that had the old 318 in front of it. If locked into low gear are you saying the trans can still make you take off slow?

 

[jasperjacko]

The factory converter has a very low stall speed. That will hinder off the line acceleration. What is your initial timing?

 

[Bruceynz]

I think from memory about 14

 

[MiradaMegacab]