87 GN done by spring or die.

corkatoa

New member
Not really. Would be nice to be done any time next year really.

building an 87 GN, body is coming off to the metal guy by december 1st(haha); 87 engine is at the machinists right now and decisions are being made. My first GN engine, have a bunch of upgraded parts to use, looking to beat the car hard through the mountains of BC. With the family, under the posted speed limit of course...

Basically, a stock GN would make me happy. Not going to be stock though, a little better for sure.

Just deciding on engine parts right now, from pistons(0.030) to bolts.

All informed opinions will be appreciated. G-body suspension tips also welcome.

Happening right now. Machinist waiting on me.

Thinking of the following:

Federal Mogul Premium Engine Rebuild Kits MHP111-311
ARP Pro Series Connecting Rod Bolts 123-6001

IMG_1092.JPGIMG_1055.jpg
 
Stay with a 2618 Alloy Piston, the 4032 Pin bosses don't live over time, especially if you ever lose the factory tune or play with the boost ?
I am sure you have already educated about GN crank under cutting, oiling, etc., ? the "tricks" ?
 

corkatoa

New member
Stay with a 2618 Alloy Piston, the 4032 Pin bosses don't live over time, especially if you ever lose the factory tune or play with the boost ?
I am sure you have already educated about GN crank under cutting, oiling, etc., ? the "tricks" ?
Here is a piece of info on this topic that I had found a few years ago when doing some research on rebuilding a 5.3.

"Most aftermarket pistons use the 2618 alloy (low silicone alloy <1%). this alloy has a higher overall strength and can untimately take a bit more abuse, but you have to run higher piston-to-wall clearances...usually .003" to .004" and will likely have more cylinder wall wear.

the 4032 has a higher silcone content which allows for less piston expansion...hence you can run tighter wall clearances. more like .002 - .0025." My understanding is that this alloy also has greater "durability" than the 2618 alloy."

I am aware of the reason, unfortunately I may end up making a compromise based on what is readily available and will suit my needs.
I plan on driving the car, but wont be taking it to the strip for sure. Still trying to find a reasonable .010 piston, not having much luck.

As for the mods you mention, I have forwarded a good tech article from GNTType to the machinist that covers all the basics when rebuilding these engines.
 

corkatoa

New member
Having said all of that, I have not been able to determine conclusively the material of the federal mogul forged pistons, other than this FM propoganda from their site, which says..
"Features and benefits include:
A patented Elastoval™ skirt for the highest strength-to-weight ratio
A range of proprietary high-temperature alloys including FMB2"
 
Federal Mogul are all basically 4032 variants, just playing with "silicon" contents in the alloy, "eutectic" for their own proprietary thermal stability characteristics.
IMO,
Do not even think about fitting a 4032 for the Boosted GN application without a Torque Plate, and thorough knowledge/experience of how to use it specific to the GN engines thermal stability and wall finish req's.
Even since the 80's..... manu's have moved to square cut oil ring faces.... NOT covered for boosted apps even to "stock" specs ?
Zinc, Moly, Phosphorous all gone from Oils replaced by parafins ?
just say'in....
IMO,
without experience, it can be a very long learning curve getting up to speed..... specific to rebuilding boosted GN engines in today's environment ?
 
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