Rebuilt engine no compression

[rsbad454]

Has anyone ever experienced a no compression issue with a rebuilt engine? I have a 304 bored to 310, rebuilt heads,, edelbrock performer intake, cloyes double roller timing chain installed straight up, comp cams 252 cam kit, holley ta 470...I cranked engine over repeatedly and no luck starting, didn't even sound like it wanted to. I thought dizzy was off 180, but made no difference. I notice by pulling #1 plug out to verify tdc I wouldn't get any pressure on my finger. I only noticed some suction on down stroke. I put compression tester on and read zero with throttle wide open.
I thought maybe comp pushrods could be too long, lifters are pumped up, cam timing off? I know I installed can dot to dot on chain sprockets with zero timing. Maybe. Sprockets were marked wrong....it's just very frustrating to sink all this time and money into something like this only to have a major issue. Any advice would be appreciated. Of all the engines I've built, never once had an issue like this.

[jeepsr4ever]

IF what you say is 100% accurate your timing set is off.

[rsbad454]

I was thinking that too and to pull the front of engine apart sucks, but I guess I need to go back to the beginning.

[rsbad454]

I suppose I should verify pushrods too...

[tufcj]

My bet is the pushrods are too long or too tight, holding the valves open. Even if the cam was off, you'd get some compression.

Bob
tufcj

[rsbad454]

My bet is the pushrods are too long or too tight, holding the valves open. Even if the cam was off, you'd get some compression.

Bob
tufcj

I totally agree....I don't get any attempt to start....I have spark and fuel just no compression. Only thing in common is the cam and pushrods. What else is odd these are non adjustable rockers, so it isn't like I adjusted too tight like on a Chevy.

[rsbad454]

Ok, I took a break from the Jeep for a bit, but decided to take another look at it. I pulled valve cover off and took rocker assembly off number one cylinder and used a remote starting button to bump engine around with my right middle finger over spark plug hole. I used my left hand to depress remote start button and two other fingers on left hand to feel pushrods as they cycled up and down with revolution of engine. My findings are when both pushrods are at the same level (should be at base circle) with number one piston at TDC and zero mark at TDC indicator on timing cover, I go to reinstall the rocker assembly, both valves are being opened slightly. I checked pushrods with stock units and they are the same length. Does anyone think the pedestals for rockers need to be shimmed?

[tufcj]

The base circle for the lobes on the cam you used may be larger than stock. You can put a shim under the bridge, but the ideal solution would be a shorter pushrod. Was the engine rebuilt, and the block decked or heads shaved? Both would also affect pushrod length.

Bob
tufcj

[rsbad454]

Yes, the engine was completely rebuilt....the bottom end was bored .030 with stock replacement pistons and the block was not decked. The heads were shaved only enough for a clean up. This is just an odd case scenario that I've never encountered before. I agree, I either need shorter pushrods or to shim the pedestals. I guess I can check and see if I didn't accidently get solid lifters instead of hydraulics. I did find these incase I need them.

http://www.jegs.com/p/Crane-Cams/Cra...03&Ntt=1659559

[rsbad454]

Here is the cam kit I bought.


http://m.summitracing.com/parts/cca-k10-200-4