Exhaust can? Cam? Polished? A little damaged? Well there ya go. There is no such thing as a camshaft a little damaged. Base circle of the cam must be round to within .0005" inch. If there was a nick or a ding in the cam that was polished out, that's more than likely your issue.

 

Understand the concept of hydraulic lifters, oil pressure fills the lifter and holds it against the camshaft. When the lobe comes around and pushes it open the oil doesn't compress. When the valve is closed the lifter is in constant contact with the lobe, but this part of the cam is round so the valve doesn't open. If there is a low spot even .0005" your done. Once the lifter gets past the low spot on the cam it will hold the valve open ever so slightly. It don't take much since the rocker ratio exaggerates the bad spot in the cam.

 

I do.

 

Bleeding the lifters fixes the issue, so that's why I don't think your valve stem clearance is the issue. Besides as soon as the car cooled down your valves would seal back up.

 

Is there a way to check and see if my cam is ok? the shop that did my cam told me that everything was true and within spec. i have the GSC Billet S2 cams. i still have the stock cam should i try swapping that in and see if that will fix my issue?

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Bleeding the lifters fixes the issue, so that's why I don't think your valve stem clearance is the issue. Besides as soon as the car cooled down your valves would seal back up."

I have done compression test when my car was cold like a day latter and i still got the same result. doesn't the lifters bleed themselves when there is no oil pressure in them? few knows shops that i have called are all pointing towards the valve stem height. i will measure the valve stem height before i take the head off so if that is not the issue i don't have to take anything apart.

 

Compression tests don't often work well on cold engines, though.

 

If it was the stem height bleeding the lifter would not have fixed the issue. Plunger would be bottomed out in lifter if it was a stem height issue. To make absolutely sure it's not a sticking valve you could make sure the cylinder has no compression then check between the camshaft and the rocker rollers with a .002 feeler gage ( some sets go down to .0015) if you can fit a feeler between any of the rollers at TDC on the compression stroke for that cylinder, it's the valve sticking open. Look for loose lifters when the rockers aren't up on the lobes.

Note: you should run the engine for a couple of seconds right before you do this

 

We will see but I bet they ****ed up the cam when they polished it. Has the cylinder head had new valves and guides installed? When it blew up was it the #1 cylinder with damage?

 

Yes everything is new in the head besides the lifters and all are GSC products and jiggly HLA.

 

Well if that is the case it certainly could be the valve stem clearance is to tight causing the valve or valves to stick slightly open. This happens when the engine heats up, the valve stem expands causing it to stick in the guide. Usually when the engine cools the valve closes, but not always. Do the above checks.

 

I fixed it for you.

 

As you can tell from my avatar, I too am a big fan of Jiggly products!

 

unless you get 0 psi

Depends on what you're trying to find

 

true dat. Should be SOMETHING there.

 

So an update I finally figured out what the problem was. What happened when I blew my motor my exhaust cam was damaged so I send it to a cam shop to get it fixed apparently they didn’t get it right. I swapped it out for a used cosworth I had and whala it worked like a charm so I oedered a gsc exhaust cam and got compression on all cylinders. Just wanted to let you guys know about my find. Thanks everyone for the helpful tips