Ok, last year around March I had made my final decision to stop going the N/A route and start putting together a turbo kit. Around that same time I had started to collect my pennies and put all of my change in this water jug, the big blue ones that you get from like Ice Mountain or Schwann's. Either way I had dubed that water bucket of change the money I was going to use the summer of '08 to pay for a lower mileaged L61 to drop in my car and put my turbo parts on that. My car right now has 103xxx on it and by the time the boost comes will probably be in the 135k area. In my opinion that is too many miles to be boosted on (7-10psi w/ the GMPP S/C reflash). My question is when looking for another motor to drop in, how many miles would be too many miles? Also how long should it take for me to drop a new L61 in?
this is a very controversial subject, because some people think thats too many miles, but some people think it would be fine. We have people on here who build engines to handle boost, and we have people who put it on there stock engine with somewhat high miles.....My opinion is you should answer a couple questions before deciding and it will help you.
1) How many of those 103,xxx miles have you drove and were they driven hard?
2) How much boost do you plan to run at MAX?
3) Is it a daily driver or a occasionally driven car?
the milage question is kinda iffy, you see some people would buy an engine with 60+ thousand miles and boost it, and some people would build it before boosting. Me personally, I bought a eco with 40,xxx miles that was in great condition, and still decided to build it and use aftermarket parts....thats just me, I wanted to be safe..Although its recommended to build an engine (or at least forge the rods and pistons) its a preference because people have done both....
hope this help
PROUD MEMBER OF JBOK.
i dont think I have heard of an ecotec failing due to high mileage yet. keep us posted
LE61T PTE6262 Powered 
1. I have driven the car since its had 62k on it, and the car is only driven hard at the track (its made 9-10 passes). Oil has been changed every 3000 miles and for the last 15000 synthetic has been used.
2. At a very max, 10 psi out of a Garrett T3 .63 a/r turbo and above said tuning.
3. The car is daily driven, being that it is my daily driver a EBC will be used. Daily driven at 5-7 psi and a high boost setting of 9 or 10 psi on above said turbo.
do a compression test and be sure, id say if your seeing 195 or better on all 4 your good to go, I did a check at like 96k or around there after being boosted for 25k and I got 210-210-183-209, a sign that #3 is starting to go but still well within safe range
1989 Turbo Trans Am #82, 2007 Cobalt SS G85
Good deal rodimus, do you think that running a leak down test would be grounds for good results on this subject also?
well both of those will be done, ill put the turbo on this motor and see how it likes it and ill let you guys know what goes on.
well did a compression test today and the compression in cyl. #1 was 180 so we stopped there and just decided id get a used motor.
