is it normal to have a bit of a "knock" after initial startup??

[Goobdog]

If cylinder #4 is full of oil Id say that it is bumping your compression number up, it would be the same thing as doing a wet test if theres that much oil in there. Also your #2 cylinder doesn't sound very well either for a freshly built motor, it sounds like its having some blow by issues. The next thing I would do is a leakdown of all cylinders to see what that tells you.

 

[TSIfreek]

Steve, I would pull the motor out and you check all the clearances or the guy that built it. Its the only way for sure what you have going.
Like I said before have all the pistons micked out and add what wall clearace you want (I would go with .0054- .0055 for your turbo and boost levels. Have the guy right down all the piston sizes and final bore sizes when he machines it. With your boost and HP level you need to know what clearnce you have so you know your not going to scuff the pistons at 30 psi. Did you call ross and discuss it with them? They may help you understand it better.

 

[Forces32psi]

If cylinder #4 is full of oil Id say that it is bumping your compression number up, it would be the same thing as doing a wet test if theres that much oil in there. Also your #2 cylinder doesn't sound very well either for a freshly built motor, it sounds like its having some blow by issues. The next thing I would do is a leakdown of all cylinders to see what that tells you.

i did a comp test this morning the same way on all 4 cylinders and i got 130, 130, 145, 160. 160 being the #4 and there is quite a bit of oil in there.

 

[Forces32psi]

Steve, I would pull the motor out and you check all the clearances or the guy that built it. Its the only way for sure what you have going.
Like I said before have all the pistons micked out and add what wall clearace you want (I would go with .0054- .0055 for your turbo and boost levels. Have the guy right down all the piston sizes and final bore sizes when he machines it. With your boost and HP level you need to know what clearnce you have so you know your not going to scuff the pistons at 30 psi. Did you call ross and discuss it with them? They may help you understand it better.

now when you say go w/ the .0054-.0055 is that ON TOP of the .020? or would that allready be figured into the .020 overbore since im running ross pistons??.. i will be calling ross monday, i wanted to wait to call them till after the guy that assembled the motor comes over here, and then he can call the machine guy and get up his ass..as of right now im looking for another stock bore 6 bolt..well just to locate one incase another one needs to be used. the pistons that i got from ross were part# 99869, 85.5 (3.366) bore, 9:1 comp. steven

 

[Forces32psi]

so the guy that built my shortblock heard my motor, he said he doesnt think its piston slap. he seems to think that slowboy racing sent me the wrong size bearings for my turned 4g64 crank?? i have NO idea why he thinks this. i pulled my motor lastnight and got the head off ,there are 2 or 3 scuffs from the piston in the #4 cylinder, and are you suppose to be able to use both of your thumbs and push down on the piston back and fourth and hear it wabble in the cylinder, front to back and side to side?? its not alot but its enough that i can clearly hear it. i can do this w/ ALL 4 pistons. is it suppose to be this way so the pistons can expand?? im pulling my oil pan off today to take a look at the rod and main bearings, but the motor spins fine and i cant get the crank or anything on the bottom end to make any noise..yet anyways.

 

[TSIfreek]

Chris, why dont you dissasemble the motor yourself. I can walk you threw it over the phone . No special tools are needed for the dissasembly and is very simple. It sounds like you have guys machining and assemleing your block and have no idea. How can he say that he thinks its the wrong bearings?? Didnt he check the oil clearance?? What a domb ass. FIND SOMEONE ELSE to do all the work like I sugested. Its going to come down to the piston clearance and you know that. Im sure that nice moly coating on all the pistons is gone and that would make me go thew the roof. Pistons maybe damaged as well but you wont know for sure untill you take it apart.
If you have to take a loss do so but dont go back to those guys. I just hate to see people get fcked. PM me

 

[Forces32psi]

nice molly coating? LAFF you mean the teflon coated skirts and ceramic coated tops that i sent the pistons off to get these coatings.. ive taken a couple of these motors apart, so i can do it. i got a digital micrometer so i can mic the cylinders tonight. i called ross today and they said that the motor should be bored .020 over and thats it!! BUT if i plan on running 30-40 psi like i want then i should leave the shortblock loose like that??? and the guy that assembled the motor said that its put together .020 + .003 for clearance.. steven