Ok, i got a D15B Block with a D16z6 Head and p28 ecu. i had a full z6 before this so its all good. only changed the block out. well i messed with my timming so much till i gave up. all it would do is sometimes backfire. i finnally checked compression and realized my number 4 cyl is only getting 120 and all other cyls are getting no compression at all. so the piston closest to the distrutor is the only one getting any compression.

for the mini me swap i used a d16y8 head gasket and my stock d16z6 head bolts. what causes me to loose compression?

 

and used d16z6 timing belt.

 

common compression losses are bent valves, and timing. teh chances of three bent valves for the 3 cylinders is unlikely. i would assume timing is off to a good degree but general if timing is off you would have 2 good comp readings and 2 bad.

 

Timing could be off. i align the cam to TDC and the crank i align the marks and that should be good enough.


what else could i be looking at. i think i put the wrong head studs in because i herd when using a non v tec block and a v tec head u gotta use certain head bolts but which ones?

 

also where was in backfireing at?...intake (hood area) or tailpipe area.

if it is backfiring from intake i would highly assume timing is off.

since you say you were messing with timing till you gave up i will point out some tips. the camshaft timing lines (3 oclock and 9 oclcock) positioning should match and line up with the valve cover to "complete" a line.

the crankshaft should line up with the arrow on the timing plastic cover. there might be four marks on crankshaft. the three marks close together are for timing referance and are unused at this stage. the single mark is your timing mark that you will use right now. line up the single mark with the plastic arrow on cover.

for the water pump you do not need to line any marks

the tensioners are known to stick so it would be wise to grab a screwdriver and force tension onto the belt then tighten the tensioner down.

rotate the crankshaft two full rotations (8 compressions) and see if your marks line back up. they should if properly done.

 

it backfired out the muffler a few times. and one time it sounded like a flame thrower real deep and i felt the heat inside my car lol. its open header right now. but no never through the intake.

 

so i should take off the timing belt and put the plastic on and align the single little mark on the timing belt sproket with 4 marks on the plastic? and the 2 marks on the cam should align at the valve cover? and UP stright up?

 

could the timing posiblly be the reason for no compression ?


anyone, what are the correct head studs to use in a mini me z6 swap?

 

no... there are four marks on the crankshaft sprocket. the single mark (the mark all by itself) on the crankshaft sprocket gets adjusted towards teh little arrow on the plastic cover.

yes after you think the timing is right..put the plastic cover on then lighlty put the crankshaft on to see if the single mark lines up with the arrow.

the "UP" isnt really straight up. the motor tilts back a little so going by the word UP is a littel weird. yes the UP should be in the up position but a better way to make sure that camshaft sprocket is in correct position is there are two marks at 3oclcok and 9 oclock. theses marks should be lined up where the valve cover and head meet.

as for the corrct head studs to use, i would assume stock is fine to get it running. maybe for future use you might need to replace them since you will be revving the block proably over the limit designed by the block head studs/bolts. i think a general rule is to use the head bolts or studs that are designed for the head and not so much designed for the block. so in this case the head bolts for the vtec head would be the wiser choice.

 

on my block theirs only one mark on the sproket. their might be 4 on the harmonic balancer. but the timing belt sproket has one and its little is hell and i align that to the mark on the oil pump correct?

 

actually yes....the crankshaft would line up with the indent stamped on the block. the harmonic balancer (i was calling it crankshaft..sorry) has four marks. the outside of the plastic cover has another indent in it.

oil pump is in a differnt location. the only "sprockets" that should be there are camshaft, crankshaft, water pump and tensioner.

 

You might want to do a leak down test to pinpoint where compression is lost. While I agree that bad mechanical timing could damage valves and pistons, another possibility is that the head/head gasket was not installed correctly and the gasket is leaking. A leak down test should help distinguish where the problem is.

 

i torqued my head bolts reall good 60ft pounds. and 10 mins later one more time. and it had a brand new head gasket and i sand the head and block nice and good. and the head was good. it has to be my timing but will that cause only one cyl to have any compression?

 

Well, a leak down test may still be worthwhile.

 

what is a leakdown test and what will i need?

 

Click here.

However, first ensure that the mechanical timing is perfect as mentioned above.

 

alrite thanks man.

 

any other oppionions will be great also.

 

just another question. could it possibly be the piston rings? because i did get this JDM block from the junk yard.

 

If addition of oil to the cylinder during the compression test leads to higher compression compared to not adding oil, then you likely have bad piston rings.

Also, are you sure the low compression cylinders aren't flooded?

 

iam just spitballin here but why not check you actuall dizzy and see if its just not giving any fire to 123 but iam just giving another possibly prob...good luck man

 

Ya, the plugs were flooded with fuel why will that cause no compression or what?

 

Excess unburned fuel can cause low compression by thinning engine oil coating the cylinder walls. The viscosity of oil is critical for proper cylinder compression.

 

dude iam telling you its proly your distrbutor module..thats why ur spark plugs had gas all over them cause there was no spark to ignit the gas...

 

OP, have you checked for spark at all the plugs?