85 Project

[rollie]

Just wanted to post my friends 85 GN project car Shawn bought the car for 3500 and started doing the 86/87 conversion and cleaned up orignal owners twin turbo MESS. We will ne taking the car to the track in a couple of weeks.

Before

After

If you have any questions about the 85 to 86/87 coversion give Shawn a call 810-614-4902

 

[forcefed3.8's]

Compound turbos like a diesel. What size turbos?

 

[rollie]

stock upper and a 70mm lower (from a DT 466e Semi) it feels pretty good at 20 pounds of boost we will see what it runs at the track, Shawn is building the 86 motor to put in the car over the winter.

 

[forcefed3.8's]

Compound turbos want alot of boost. Will be interesting to see what it does.

 

[rollie]

How much boost can the 85's handle if the tune is right I was told the head bolts and crank are a little weaker than the 86-87 motors?

 

[forcefed3.8's]

They are the same.

 

[rollie]

I thought the 86/87 had rolled fillet crankshafts I guess I was told wrong

 

[charlief1]

I thought the 86/87 had rolled fillet crankshafts I guess I was told wrong

All of the TB engines and the 4.1 came with the rolled fillet cranks in them from the factory. There are some minor differences in the blocks with oilling passeges and deck height but everything pretty much interchanges from 77 & 1/2 till the end of the RWD blocks. The only diff is the 77-78 heads are low port and the 79 up are high port except for the TTA.

 

[usetaboost]

subscribed. Would like to see more on this. Looks interesting.

 

[rollie]

All of the TB engines and the 4.1 came with the rolled fillet cranks in them from the factory. There are some minor differences in the blocks with oilling passeges and deck height but everything pretty much interchanges from 77 & 1/2 till the end of the RWD blocks. The only diff is the 77-78 heads are low port and the 79 up are high port except for the TTA.

Good to know Thank you!

 

[rollie]

a few more pictures

 

[Spooln1]

thats a lot o piping on the original set up. Cool looking set up.

 

[rollie]

hey guy's need some help the car runs great under boost when the car first starts once the car warms up it has a slight miss fire we did the 86/87 conversion I checked/changed coil, plug wires and plugs and it still misses when the the car warms up.

The car ran fine before the conversion we did notice it is blowing black smoke now under boost.