Continuing with Wilson's problematic 72 Skylark

That's my plan.

I am getting one of the Quadrajets off Mark @ Quadrajet power. I am not sure what distributor is out of. Its an HEI , but I am sure its gonna need tweaked.

Hoping this finally resolves the issue so I can start driving the car.

 

Best I can tell, you've never tested ignition supply voltage with the engine running. Testing it with the engine NOT running is futile. You could have ten thousand ohms of resistance, but if there's no current flow, the voltage will be where it should be. Engine running, alternator charging at ~14+ volts, you'd better have AT LEAST 13 volts at the HEI power connector.

Engine fails the power-balance test. Could just be #6 spark plug. Clean plugs and re-test.

What is the elevation of your locale? I'd be PISSED at 120--125 psi on a cranking compression test around here. I expect to see ~150, and I'd really like to see 170. Low cranking compression can be a sign of mis-timed camshaft...or slow cranking, or high altitude, or a defective pressure gauge, or a wild camshaft, or low static compression ratio, or...or...

The good news is that the leakdown test is fine. Valves seal. You have visual proof that the cam 'n' lifters are OK. I wouldn't trust adjustable pushrods any farther than I could throw them...but they'll get you by for now IF they're properly adjusted.

The ohmmeter readings for the plug wires are fine other than they're not especially even. Could be an invalid test, could be wires are just starting to "go". You have spark at the plugs; I'm not too worried.

WILL THE IGNITION COIL FIRE AN HEI-CALIBRATED SPARK TESTER?

Fouled plugs, no power, hard starting, runs bad, sometimes backfires. Could easily be a weak ignition coil. That doesn't account for the crappy compression test results, but maybe you have a bad gauge, or live at high altitude.

 

Not much different than here. It's certainly not Denver.
FIRST: Verify your compression-tester gauge. I compare to other gauges using my shop compressed-air supply. A bit of brass, a few air system quick-couplers... (One coupler to match whatever quick-connects are used by your shop system, and at least one more--a Milton "M", also known as "Industrial Interchange". Every compression tester and leakdown tester I've dealt with that had a quick-disconnect has used that style coupler)





Assuming that the compression tester gauge is reasonably accurate and repeatable, I'd be looking at cam timing. At TDC Compression, both valves will be closed. At TDC Exhaust, both valves should be VERY SLIGHTLY open. Within a few degrees of TDC-E, the valves will be open about the same amount. Advanced of TDC-E, the exhaust will be open more, and after TDC-E the intake will be open more. Squishy lifters makes this harder to verify. Anything more requires a degree wheel and dial indicator equipment.

After that, you could drop a borescope into the spark plug hole to see how big the dish is on the pistons, and--maybe--how far down in the hole they are.

 

When I did cylinder leak down, I verified that I was on TDC compression. Both valves closed and piston right at top. If I bumped it, exhaust valve started to open.

My compression tester I used was bought at HF.

Weird thing is, the guy I bought the car off of said the car ran great for the 1st couple months after the 455 swap. He said it started to go downhill slowly and got to the point where it is now. That is what made me think cam lobes/lifter issue right away.

One would think that if the cam timing was out, it would have never ran good from the beginning.

Original owner also stated he re-verified cam degree. I have not done that.

I too, thought it was ignition related too. I replaced the cap, rotor, coil, and module. Car still ran the same.

I also suspect the carb as well. It's a Street Demon carb that I know nothing about. I ordered a performance Qjet from Mark @ Qjet power. Would rather have that rather than that Street Demon.

I have not verified base timing, maximum mechanica advance, or vacuum advance.

I wanted to make sure motor was sound before tackling the easy stuff.

Does anyone know how accurate the cam grind is on TA Performance 212 cams? Again, both original builder of motor (Wildcat Performance out of GA) and owner verified cam degree.

Chris

 

Larry,

Degreed many cams in my time but was just wondering if TA's cam grind was better/more representative than some of the other manufacturer's cam specs.

That's what I heard too. That is why I wasn't too concerned with cam not being degreed correctly.

Chris

 

Here is some information that the original owner sent me from when he got the motor built.

I guess he was dealing with Richard Lesseter and he was the one who had Mike from Wildcat Performance do the work.

 

I've seen where people can just install cams straight up and not degree them in to verify mfg's grind specs. I know that Buick's are a little more "touchy" when it comes to that; hence why Buick cams are degreed more often than say... a SBC.

My question was are TA Mike's cams historically better with the specs than say Comp, Crower, etc...

 

I'll shoot Jim a message.

Other thing I noticed is that if you look at the .PDF I attached, the cam was degreed by Mike @ Wildcat to 108.5 intake centerline. LSA is 112. Any reason why the cam would be advanced 3.5 degrees? BBB run better with advancing the cam?

I'm a turbo Buick guy by heart so BBB are still somewhat new to me.

 

That was my thought but I am sure its not the case. I am assuming that that is what is in this motor, never took off the front cover to confirm. They are but my cam was a custom grind and was dead on.

I sent Mike @ Wildcat a message... haven't heard back from him yet.

 

So you say you have not verified base full advance or vacuum advance concerning timing at all yet changed all these parts?

 

Only parts I changed were ignition parts. No matter what condition ignition parts are in, I always change them...it's just something I like to do.

I planned to change the carb from the beginning regardless if it ran good with street demon carb.

 

Find someone who can check your timing.

 

I know how to check timing, just wanted to cover everything else 1st.

Car sat for a long time after these issues arose and I wanted to verify all issues; focusing on stuff that cost more money to repair 1st. May sound nutty, but that's how I operate.

Long history of easy stuff not being the culprit.

 

Where are we at with this one? Carb change?

 

Got one of Mark's carbs specifically built for my configuration.

Havent had a chance to put it on yet. Right now, we are sitting with the manifold on and just waiting to get carb on so I can see how she runs!

Hoping that it the issue; well that and timing.

I will keep you guys posted!

Chris