cam advice

[thallium]

I recently aquired a 70 cuda. The guy who had it before me does not know what is in the engine.  I have not checked yet, but i'm pretty sure the way the car drives it has close to 2:76 gears. The engine runs good, but does not have any ummfff.  It starts crappying out at 4,000 RPM's and it's all done by 4500 RPM's. It's a dog for sure.

I know gears are one reason. but i do know it's not all gears. I have a 68 charger with a hughes 2328 cam with 3:23 gears and it runs high 12's in the quarter, so gears do help, but with all the torque with a  440 it should pull decent with 2:76 gears. i do like the tall gears for the street, so i'm going to leave them in. I was looking at this cam.

http://www.hughesengines.com/Index/products.php?browse=category&level0=QmlnIEJsb2NrICA0MTMtNDI2LTQ0MCAoUmFpc2VkIERlY2sp&level1=Q2Ftc2hhZnQ=&partid=21847

Is there any way to tell if I will have piston to valve clearance without pulling the whole engine and tearing it apart? I think the cam above would give it some pep if it will go in without hitting the valves.

It's a 440 engine, 4 speed 2:76(pretty sure, they are tall), seems pretty stock, might even have an RV cam in it. It runs good, but craps out around 4000 rpms. Not sure what heads are on it. They are cast iron, but i'm not sure if they are 906's heads or what yet.

[71chally416]

The rearend gears will no make an engine "Crap out" abouve 4,000rpm. If anything it should be a dog down low and then run better at higher RPM.

If it's really that weak running I doubt that a cam change will transform it into a top end screamer unless the valve springs are really bagged or the lifter preload is way off. I'd do a compression check before doing anything else.

[dodge freak 2]

It could be weak valve springs--not everybody puts new springs with a new camshaft. I would pull the heads and get a valve job and new HP springs. This way it be all set upstairs if and when you change the camshaft.

[Moparal]

I'd pull the heads, see how far the pistons are in the hole, see if they have valve reliefs, and that will help determine a cam shaft for you. I'd bet the cam is not installed on center correctly. A cheap timing chain can throw the center line off as much as 10 degrees. Also go through the heads. I would check and see if you have enough fuel volume to. If you only have a couple of lbs, that will keep you from running higher rpm's. But not the reason for it being a bottom end dog

[Chryco Psycho]

you can check piston to valve clearance by using a dial guage & depressing the valve with the piston 6* before TDC for exhast & 6* after for intake

[thallium]

Thanks, that is a little beyond my scope of skill. I can find TDC of the number 1 cylinder, but I have never used a dial gauge. I might have to find someone that knows how to do this. Thanks for the info Chryco and all. Thal

[72cudamaan]

I'd suggest the basics first, like checking to see if your vac. advance is working properly. Fuel level in bowls is okay?