cylinder head trouble

[440charger68]

I bought some 318 cylinder heads cast#302 they are closed chambered i figured they would bump up my compression ratio but i think my problem is i gasket matched them without changing out the small 1.78 valves i have lots of rpm now but no bottom end torque like i use too. Does that sound like the problem??

[chargd72]

Periods are everyone's friend.
I have a set of 302s as well.  If you gasket matched, I'm assuming you upgraded manifold and carb too?  If so, that might be where your torque has gone.  Give us your full engine package and we could probably be a little more helpful.

[440charger68]

ok thanks, i have a edelbrock air gap intake, and a 600 cfm holley carb. My cam is a lunati vodoo Duration 262/268, Lift .475/.494 and i have hooker headers. The cam was reccomended to me by firefighter ron eventually i wanted to upgrade the 1.78 valves too 2.02

[440charger68]

Come on you guys! help will be much appreciated!

[heyoldguy]

When you changed the heads, is that all you changed?

[440charger68]

no i changed out my intake for a edelbrock air gap intake, changed out my carb for a holley 600 and also changed out my cam and lifters lunati vodoo Duration 262/268, Lift .475/.494. I also added some hooker headers replaced all gaskets too. I didnt do anything to my heads just gasket matched them, the heads were rebuilt when i got them.

[heyoldguy]

Okay from what I see, with the parts you added, you TOLD your engine to make more power higher in the rpm range and to loose a little on the bottom.

That cam is 112 LSA and calls for 108 ICL. Where did you time the cam it when you installed it? What are you running for initial and total ignition timing? An adjustment in those two areas could get you back what you feel you lost on the bottom, if they are now incorrect.

As for the heads, they are not the problem. They probably flow as good as the heads you took off, and gasket matching without doing other things to the heads will make little to no difference in how they flow. You will have to make big changes in the valves and the areas under and close to the valves, before the gasket and pushrod pinch areas will have any flow effects.

There are some areas you don't want to skimp on when you are looking for power. There has been some great advancements in intake manifolds so we must not leave them out, but, Dad told me over thirty years ago when he was building engines in NASCAR, "Jimmy, there are three secrets for building horsepower. The first two...........are cylinder heads...........and the third and MOST important, CYLINDER HEADS!" All throughout the Chrysler engine line, from the 318 to the 440, the factory valves and ports are so small, that you cannot port them out enough, or install a valve so large, that you loose your bottom end torque.

[440charger68]

so i found out LSA is lobe separation but what is ICL?? when i installed the cam i just lined up the dots i have did some research and some places say i shouldn't of done that, but instead should of advanced it to where the dots line up. Is this right? my goal in adding parts was to gain low end torque thats why i went with the closed chamber 302 heads 

[heyoldguy]

ICL = Intake CenterLine. The number of degrees after TDC that the center of the intake lobe should be according to the cam card. In your case 108* ATDC. If it is retarded, say, 112 degrees instead of 108, you will be loosing some bottom end power. That is why it is always best to degree the cam instead of just lining up the dots. There is a great deal of information on the net about degreeing a cam.

Before people jump my case. Your cam is ground 4 degrees advance, i.e. ICL 108 on a 112 LSA. 112/112 would be straight up and  114 ICL on 112 LSA would be 2 degrees retarded. You should have been able to line up the dots and the cam should be  ICL 108, but you can't count on it, the timing chain and gears my have not been made right or the cam grinder my have made a mistake. You should always degree in the cam and not just line up the dots. I'm sure this has been covered extensively in these forums somewhere. Use the forum search engine and search, degreeing a cam, I betcha there is a lot of discussion on the subject.

[440charger68]

ok so it sound like i should advance my cam a bit, any way i can do that without the degree tool?

[heyoldguy]

Please don't go changing the cam timing without finding out where it is right now. Find someone who has the proper tools to time the cam or buy the tools for yourself, they are well worth the cost. The piston stop, a degree wheel and a dial indicator with a magnetic base will only cost a total of about $60. Besides you may be able to get the improvements you wish with just a simple distributor or carburetor adjustment.

[440charger68]

word of wisdom! much appreciated will get that set up pronto!