I'm at an impass and would like some insight.

Compression tested both of these motors using standard piston checker and procedure from Kevin Lander's site.

86 GXL. 170k on the original motor.
Rear Rotor: 3 even pulses of 35+ psi, final compression 90psi
Front Rotor: 3 even pulses of 35+ psi, final compression 110psi

87 GXL w/ factory reman at 40k.
Rear Rotor: 3 even pulses of 35+ psi, final compression 120psi
Front Rotor: 3 even pulses of 35+ psi, final compression 130psi

I want the 86 to recieve the turbo conversion, but the 90 psi on the rear rotor bugs me. I was depressed about the rear rotor, but excited that the front one was doing so well at 170k. I don't really want to have to swap motors between the two vehicles.

Would putting some ATF fluid into the rear rotor maybe free up a side seal or something to bring that compression back up? I know someone was making 400+ whp on a 200k engine. I was unable to find anything about his compression tests.

My 5/6 ports don't work on the 86 and i believe one is open and the other is shut. Could this give me false readings?

Thoughts? discussion? I'm awaiting one more part to get here (comes this week hopefully) and I'll be turbo'n one of these motors.

Both motors are NA. Thanks guys.

 

why not just buy a turbooII engine?

 

I couldn't agree with you more!

For all the time, money, and aggrevation just sell them both and by a TII. I just saw some nice ones available here on the forum.

 

i would roll with the 87 just cause it has less miles and better compression then throw the 86 into a cheap shell and have two cars or sell the 86 motor and use some of the money to put towards the turbo conversion

that's my 2 cents

 

I have two RUNNING vehicles, just happen to be in love with my 86 (first 7). I have EVERYTHING I need to turbo one of the NA motors, except my oil pedestal (coming this week). I also put all of this together for under 500 dollars. Mani's, injectors, AFC, turbo, DP, etc. etc. etc.

Why would I want to purchase a TII motor?

Maybe I should elaborate on my plans. I don't want a high boosting motor. I'm not looking to make 400 HP. Hell, I'm not even all that interested in 300. 250 would be a nice mark to shoot for.

I can make that far quicker on an NA, with less $$$. Not to mention, as said above, both of these vehicles are running. I expect to pull this turbo swap off in one day, two at the most (Sat and Sun).

Switching to a Turbo motor involves getting an ECU, harness, AFM, boost sensor, and a bunch of other crap. Who, in their right mind, would believe that swapping in a turbo motor is easier or cheaper?

I would agree, if I had a shell sitting around with no motor or a blown motor.

Again, these motors are in running, daily driven, vehicles.