I recently installed Cosworth Cams in my IX went to get tuned and we ran into all sorts of problems. I picked up 0whp and about 10-15 tq off the cams. We tried a bunch of things, went over the cam install and everything looked fine, but still couldn't get any WHP gains.

I went to a local shop last night and they did a boost leak, compression and leak down test on my car. Cylinders 2,3 and 4 came back with good results 145psi and a little higher, however cylinder 1 gave a lower compression (128 psi) and had a 35-40% leak down. They opened up the throttle body and it seemed like air was leaking out from the intake manifold. The spec compression for the IX's is 145psi.

I did some searching last night and it seems that if I had a bent vavle I would have had almost no compression and a lot more leak down on the cylinder. Is it possible that something is just obstructing the vavle?

The leak down tests were done with my crank set at TDC.

The shop I went to said that I have either a improperly grounded camshaft or a bent valve. Anyone have a problem similar to this before? Is it weird that it is only happening on one cylinder? I really want to be sure of the problem before I end up spending over $1k in parts and labor for someone to pull the head only to replace a $20 valve.

 

Any other signs? Sounds or noises?

 

Nope, no noises, car runs fine, just can't get it to make power with the cams.

 

30 views and only one person has replied? :\

 

Hmmm, cracked piston on #1 maybee. Pull the plug on #1 and take a look at the piston top with a bright flashlight. If it's wet then you probably have a cracked piston.

As far as the power goes, you said you picked up 15 ft/lbs but 0hp, could be a mivec problem. If the cam was staying advanced you would not pickup any power / loose power up top.

Who did the cam install?

 

I installed my own cams.

If I have a compression problem, wouldn't relate with the lack of power? I'm guessing there's some tuning that needs to occur, but I don't want to tune my car around a mechanical problem.

 

I had a cracked piston, so that may be what it is

 

If Cyl-1 is at TDC, it could be at 2 different strokes. What stroke was it beginning when you set it at TDC? If it was beginning the intake stroke, aren't the exhaust and intake valves slightly open here?

I'm no expert. Just throwing out ideas.

 

^ good advice. I suggest looking for a valve imprint as well.

If you know someone with a bore scope that might help you see in the cyl better.

Does the car smoke? How does it idle?

If you did your own cams I'd probably pull the new ones and put the stockers back in then do another compression test.

You didn't have any extra parts left over after the install did you? (joke)

 

According to the shop that did my compression and leak down test last night, it should not be leaking at all on any cylinder. I'm not sure which of the 2 strokes it was beginning.

Sorry if I am not the most helpful with answers, but I am not the most knowledgeable regarding how the internals work with each other.

 

haha, no "extra" parts

Car doesn't smoke at all, just a little cloud from the exhaust when I WOT. However, I have a somewhat rich tune as well. The idle is fine, it has the lope from the cams.

 

Crank the car over and perform compression test again.

 

Damn, im about to do a Cosworth install myself. Hope i dont run into this problem. Good luck man.

 

I'm going back this weekend to pull out the Cosi intake cam and do another compression test.