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I don't know how fast a l67 is with my setup... But this thing pulls hard and will screech the tires at 40 around 3/4 throttle (only boosting about 6lbs). Is that fairly normal or does that sound like the engine is putting out a little more power than normal (as the higher compression L36 will do with less boost).
It's real... If I take the s/c belt off I can beat on it with zero KR. And as long as I don't let the boost get over 5-6lbs the KR is at or close to zero. I'm seriously considering buying a 4.0 pulley for it... lol
Are you using an mps system or press on?
A couple things to check IMO:
Catalytic convertor clogged?
DP 3"?
Compression ratio
I think you are on to something with the compression ratio. The L36 should be about 160psi and the L67/L32 should be much lower. Like the other guys said, have someone with tuning experience take a look at it if it appears to have the lower compression pistons.
I have ZZP's MPS
No catalytic converter. I have headers with 3" dp.
I'll try checking the compression on it sometime. I'm also thinking about closing the gap on my plugs a little... maybe .045 or so. They are gaped at .053 right now. Maybe that will help...
CC's are both 64 cc.Quote:
Originally Posted by rolyat
The only difference in the bottom end are the rods, pistons, pins, balancer, flexplate, and cam gear.
You cannot check compression ratio short of boroscoping both types of blocks or CC'ing the pistons.Quote:
Originally Posted by Rico
The cam gear in a N/A block is 1* advanced. Not exactly detectable.
Compression test values are quite a useless figure considering ring wear and valve/seat wear would negate any differences.
Closing the gap isn't the best way to solve this.Quote:
Originally Posted by rolyat
Have a known good ICM you can swap in?
When I first top swapped my car wouldnt run KR free past 2 psi until I swapped out the ICM for another unit.
Hmm. This argument has come up before. I think that 2 engines with the same exact cam profile and 12% difference in compression ratio would create pressures that are noticeably different, especially at cranking speed. I understand that that the NA cam is degreed differently (only 1% as you say) but the lobe separation is exactly the same...no? If the rings are bad enough to negate the pressure differences then the motor will probably need rebuilt anyway. Then you'll surely see what rods and pistons are in there.Quote:
Originally Posted by matt5112
BTW
CC'ing the cylinders at BDC is not that hard and may be an option for you.
Matt5112
I understand that you are probably much more experienced than I and if I'm wrong go ahead and beat me up. I'm learning like everyone else here.
Its possible, but I challenge you to find accurate and repeatable numbers for both short blocks.
Boy I wish my L67 was back in the GTP 'cause I have an L36 in the driveway. The curiosity is killing me. LOL
My compression tester wasn't holding the pressure, but it looked like the needle was bumping up to 145psi and maybe a little higher.
I just swapped the ICM and it made no difference.
I took off my ZZP plug wires and put in my brothers ZZP wires. It got rid of all the misfiring and gave me a noticeable power gain... due to the fact that I can finally put the pedal on the floor! There is still some knock (around 5*) at full throttle and higher rpm's. I'm thinking the ZZP plug wires are crap in general and I'll get some OEM replacements. I guess I just went from one bad set of wires to another and another lol. Maybe that will get rid of all the KR.
That's supposed to be common knowledge now haha
I guess I missed the memo... lol
Does anyone have any recommended quality plug wires that aren't overpriced and will get the job done? Accel, Walker, ACdelco?
Advance, buy a lifetime set of autolites... Done
Were talking about the sc motors not the na
Android Fire
How, are the wires different?Quote:
Originally Posted by z3r0
I went to oreillys and bought the lifetime Borg Warner's. Ready to get these sh**ty ZZP wires off my car and soak them in some gasoline... then watch them burn!!! I'll buy my brother a new set too. Lol
The new wires helped. I can go full throttle without any misfiring and the KR stays between 0-4* so it was definitely an improvement! I'd love for it to stay at zero, but this is the best it has been since I've owned the car so I can't complain too much.