Any experience? - "G head" with "fast burn" pistons?

[Putter]

John, where did you get your std bore mahles? As I have some 'on order....ya...' since december 8th...

[Una]

3 month backorder? Only one vendor can provide service of that caliber. ;>

[Putter]

Hehe, I'm not sayin names, because I don't want to sound like an ass.....

[johnl]

Putter - when I asked the vendor "Do you have them in stock and when will they ship?" the answer was "Yes, tomorrow." I suspect our vendors make too little money for too much work, so I am reluctant to name names. It took more than one month; when I started making daily contact - emails or telephone calls - then they were finally shipped. I suspect that they mistakenly thought they could get the pistons ASAP. Screwed me up BIG TIME because I was shooting to have my car ready for the TU dyno day last weekend. Had the vendor been honest about it, I would have ordered instantly available forged pistons from TU.

Sergio/Kedavis/Una - THANKS. I had no idea. For my T2 convert, I have T2 distributor and loom/overlays. I also have three logic modules - (1) Stock T1 GLH, (2)Shelby GLHS 1986-87 Stage II # P5249670, and (2) Mopar Performance T1 "off road" # P4532325.

In the absence of a calibration, should I Grainger the Mopar Performance to get the boost while retaining the T1 advance curve? Or, can I get a calibration "long distance" that will get me the aggressive advance curve that my G head needs?

Darn it, I wish I could had my car running!

[Putter]

I'm in the same boat, I've been sitting with my engine apart since december, and I'm kind of at a standstill for trying to get my intercooler figured out and plumbing air filtration, wiring for the 3bar conversion and t2 elecontrics.....I'm just stuck when I don't know where anything is going without putting it together. It is indeed frustrating. Come time I get one more part ordered I'm putting the damn thing back together and leaving my 9.5:1cr until pistons come or I get fed up, get my refund and go buy forged. I'm ran a G-head and flat tops (heh scary) @ 12psi last fall retarded 4 degrees.

TU should be able to help you out on your Logic module, if all else is stock changing the timing curve to something that is pretty close for your engine should be fairly simple, as VE changes would be more difficult to nail without a dyno.

On the other end of it, if your running 2.2 t2 electronics with the G-head, with the swirl timing curve, you probably will definatly be safe for running a little too much boost if you get carried away one night or a wastegate hose pops off (man does that suck)

An intercooled 2.2 with t2 pistons and bathtub head should be super safe at 15-18 psi on premium fuel, if I ever get mine going again, I've figured that 20-22psi should be do-able with the same setup as long as I keep an eye on whats going on.

Talk to TU about a calibration.

[turbovanman]

Quote:

Originally Posted by Putter Hehe, I'm not sayin names, because I don't want to sound like an ass.....

Why, I know who it is, lol! but thats why the vendor section, to let people know who to deal with and who to avoid.

[beefalobilly]

i know how you feel john, I was wanting to get to the TU dyno day also, but couldn't make it because I'm behind on my omni also, I'm at this point where it's become somewhat burdensome to work on the car with school and work. Of course all it takes is a few moments in the drivers seat to recall the joy of driving the car and then I'm good for working a couple more hours on it

[turbovanman]

Quote:

Originally Posted by beefalobilly i know how you feel john, I was wanting to get to the TU dyno day also, but couldn't make it because I'm behind on my omni also, I'm at this point where it's become somewhat burdensome to work on the car with school and work. Of course all it takes is a few moments in the drivers seat to recall the joy of driving the car and then I'm good for working a couple more hours on it

Thats what keeps me going, otherwise I would have given up last year.

[My96z]

Quote:

Originally Posted by johnl Simon - Your guestimate was about right. In looking at the posts at "induction - 782 chamber," I learn from "4 L-bodies" that the chamber volume of the swirl is 49-50 cc and the G is 55-56cc, and that the piston dish volume for '85 G pistons is 9cc while for the 86+ swirl pistons is 24cc. So, 85 G head w/ 85 pistons is 55 + 9 = 64cc and 550cc/64 = 8.59CR stock. And, 85 G head w/ 86+ swirls is 55 +15 = 70cc and 550cc/70 = 7.86:1 CR for the G head/swirl piston combination. 8.59 - 7.86 = .73 decrease in CR. More than half, less than one.

Thats for a 2.2 correct? Any guestimation for a G head on a 2.5?

Jeff

[Mike Radowski]

do the same calculations but swap 550cc with 625cc.

[moparzrule]

The dish on 2.5 pistons is bigger though, so you can't just swap 550 with 625 or else you get 9:1 + compression ratio.

[Mike Radowski]

my bad, I thought the 2.5 piston cc was listed in an earlier post also.