Fresh Engine. Low Compression

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Gotta say I've not heard of washing down the cylinders on an EFI setup. You'd need to crank that sucker over 1000's of times with the injectors firing. Cranking with the starter is maybe a few hundred rpms. Now on a carb yeah maybe. Your oil would smell of gas and plugs fouled.

Sounds more like either bent or wrong length pushrods, or the valves not adjusted properly. Have you squirted some oil in the spark plug holes and rerun the compression test? That may do the trick.
 
i dont mean to be a dick but........ the oil reaked of fuel. i pulled the dip stick and could smell fuel.
I agree though i have never heard of it happening myself. now i did try to get her to start for the better part of an afternoon pulling my hair out.... thought maybe it was a timing issue, the dizzy is stock from an 87. the plugs were fouled out. blew her dry with compressed air and new plugs newer dizzy redropped dizzy. shoulda fired right up. then the compression test. i have checked the push rods and rockers that was my first thought. the heads have all new parts.
thanks for the advice i will try the oil and see if it fires.
 
heres a thought, a long time ago in high school i helped a friend rebuild, we were excited to get the engine reassembled... went well... never noticed they gave us the wrong rings for a non bored 302.... similar wtf.... just a thought....
 
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That is possible that the wrong rings, i bought the pistons as a kit and used the rings supplied.
up with a mighty thirty pounds of compression in each cylinder! I just know that shortly there is going to be one of those Doh Moments
When you put oil or trans fluid on top of the ring it acts as a seal. look up wet compression testing this is not some far fetched practice. it is the correct way to test for bad rings, other than a leak down of course. i am going to use it as a way to get enough compression to fire the engine and retry the break in. if it does not work i will then rebuild again.
 
That is possible that the wrong rings, i bought the pistons as a kit and used the rings supplied.

When you put oil or trans fluid on top of the ring it acts as a seal. look up wet compression testing this is not some far fetched practice. it is the correct way to test for bad rings, other than a leak down of course. i am going to use it as a way to get enough compression to fire the engine and retry the break in. if it does not work i will then rebuild again.

Hopefully they gave you the correct kit for a 306 (4.030") and not a 302 kit. It'd be difficult for a bad hone to get the same low compression in all 8 cylinders. Seems like a problem with the rings IMO.

You didn't use synthetic oil for break in right? Is it possible your injectors are stuck open? Have you checked to see if you have good spark?
 
i checked ptv with stock pistons it was a no go with the new heads so i broke it down and balanced the assembly with new sealed power pistons hyperutectic .030 over... heafs are ported gt40s with a new valve job and 2.02 valves e303 cam and 1.72 rr. port matched cobra lower and upper ported for 75mm tb. 32 lb injectors feom cyote motor lightning maf and sct tune. i have done the injector leak down test. they passed. during build i shimmed the rockers. i even did the leakdown test with the rockers off the head.
 
i checked ptv with stock pistons it was a no go with the new heads so i broke it down and balanced the assembly with new sealed power pistons hyperutectic .030 over... heafs are ported gt40s with a new valve job and 2.02 valves e303 cam and 1.72 rr. port matched cobra lower and upper ported for 75mm tb. 32 lb injectors feom cyote motor lightning maf and sct tune. i have done the injector leak down test. they passed. during build i shimmed the rockers. i even did the leakdown test with the rockers off the head.

32# injectors are pretty big for your combo but not so big it'd flood it so long as the tune is good. What size fuel pump? Are you customizing the tune yourself? Seems that maybe the injectors are dumping too much fuel possibly and your not getting enough spark. What duty cycle are the injectors set for?
 
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fuel pump stock. have new 155 waiting. the tune was burned by bama tunes worked fine before i tor it down. i only had e7 heads and an untouched cobra intake previously. idk what the duty cycle is cant be much for now. hopefully if all goes well a supercharger in the future.
 
i checked ptv with stock pistons it was a no go with the new heads so i broke it down and balanced the assembly with new sealed power pistons hyperutectic .030 over... heafs are ported gt40s with a new valve job and 2.02 valves e303 cam and 1.72 rr. port matched cobra lower and upper ported for 75mm tb. 32 lb injectors feom cyote motor lightning maf and sct tune. i have done the injector leak down test. they passed. during build i shimmed the rockers. i even did the leakdown test with the rockers off the head.

You really lost me here... So did you check PTV with the pistons that are currently in the motor?