Finished!! Forged piston block, Custom valve head (flowbenched)

[Una]

Wild.. So it'd be what, a 3.3L with the .2" overbore? Do they make stroker cranks? hahaha..

[irocelectric93]

Brent do you have a separte cardomain for your duster? If so i want to see it.

[Reaper1]

There was a stroker kit out there made by RPW. I happen to have one in "The Beast"(no I haven't had a chance to run it yet...got other things I'm trying to get done first). I went looking for it a couple of months back to see if it included pistons, but I couldn't find it on their site. There "MAY" be another company offering a similar kit here in the states, but I'm unsure of that.

BTW, if anybody knows if the RPW kit came with psitons, can you tell me if they were cast or forged units? Thanks....

[Ondonti]

For those looking to spend every last time of their retirement savings.......

http://www.3si.org/forum/showthread....3&page=1&pp=10

The 6g72 3.7L billet steel stroker crank has just been completed.

I wont be able to afford it for a few years. Next they are working on a crank that will stroke the 3.5L to 4.5L
Can you say baddest 6 cylinder motor in motorsports? GM 3800 and 2jz-gte fear this!.

[Ondonti]

Quote:

Originally Posted by irocelectric93 Brent do you have a separte cardomain for your duster? If so i want to see it.

The previous owner had a cardomain site for it.

As yet my car stuff is basically on the Spirit's page.

I got the front end of the car on. had to do some interesting work to make the P body bumper cover fit without the steel bumper.

Im going out right now to do the last welding on the suspension rust problem I had (top of wheel well rusted out including the top of the shock bracket).
Welding at night is so much nicer then during the HOT day.

[Reaper1]

That 3.7 stroker is nice, very well thought out. My question is the same as another person's on that thread...what's the rod ratio? I suppose it still wouldn't be bad if it dropped it down to 1.65 or so(still better than the 2.2). I still think that messing up our already perfect(VERY close to it) 1.82 is kind of a waste. I can see dropping it a bit by upping the stroke to like 3.25. That'll yeild about a 1.7 IF you could raise the pins in the pistons high enough to accept the stock length 5.5" rods. I'm willing to bet that the 3.7L stroker uses pin caps because the pins are way up in the oil ring lands and the the rods are stubby little buggers. Nothing TOO worng with that, just not practical. We ***** about spending $5000 on a car! That kit alone costs $7500! It's a RACE set-up. It won't be practical for the street at all. It is meant to move a volume of air so that larger turbos can be spooled lower in the rpm range.

My point is this...it is a work of art and will serve its purpose VERY well. It tests the limits of the 6G72 and undoubtedly will make HUGE power. It isn't something any of us could actually use. Even those VERY nice heads that were just completed won't flow enough air to make it worthwile.

IMHO the 3.2 stroker was/is(if it is still available) a good upgrade for a powerful street car. It gave more displacement, more power, was fairly affordable, and was capable of working in conjunction with the rest of the engine even if it wasn't modded to the max.

With all that being said, now I have to find out if it is still available!

The one thing I liked about the 3.7 kit that I used on my stoker for my 2.2 was that it used larger bearings/pins so that standard Chevy rods could be used. I did that on mine, and I think it's a good move. The only thing I still have to work out is if I have to chamfer one side of those rods(they're meant to be run back-to-back, not individually, so one side of them doesn't have a chamfer IIRC...).

[93sundance]

Im going to have to make a trip out west someday just to see this beast in action.

[Ondonti]

Quote:

Originally Posted by Reaper1 That 3.7 stroker is nice, very well thought out. My question is the same as another person's on that thread...what's the rod ratio? I suppose it still wouldn't be bad if it dropped it down to 1.65 or so(still better than the 2.2). I still think that messing up our already perfect(VERY close to it) 1.82 is kind of a waste. I can see dropping it a bit by upping the stroke to like 3.25. That'll yeild about a 1.7 IF you could raise the pins in the pistons high enough to accept the stock length 5.5" rods. I'm willing to bet that the 3.7L stroker uses pin caps because the pins are way up in the oil ring lands and the the rods are stubby little buggers. Nothing TOO worng with that, just not practical. We ***** about spending $5000 on a car! That kit alone costs $7500! It's a RACE set-up. It won't be practical for the street at all. It is meant to move a volume of air so that larger turbos can be spooled lower in the rpm range. My point is this...it is a work of art and will serve its purpose VERY well. It tests the limits of the 6G72 and undoubtedly will make HUGE power. It isn't something any of us could actually use. Even those VERY nice heads that were just completed won't flow enough air to make it worthwile. IMHO the 3.2 stroker was/is(if it is still available) a good upgrade for a powerful street car. It gave more displacement, more power, was fairly affordable, and was capable of working in conjunction with the rest of the engine even if it wasn't modded to the max. With all that being said, now I have to find out if it is still available! The one thing I liked about the 3.7 kit that I used on my stoker for my 2.2 was that it used larger bearings/pins so that standard Chevy rods could be used. I did that on mine, and I think it's a good move. The only thing I still have to work out is if I have to chamfer one side of those rods(they're meant to be run back-to-back, not individually, so one side of them doesn't have a chamfer IIRC...).

I think the Rod Ratio is 1.58:1
I dont personally have a problem with it. The honda guys run a much lower #. stroked 2jz-gte guys run lower. They all rev beyond 10,000 rpms.

The low rod ratio was actually dont on purpose to help control detonation. I would never use that setup with anything besides a Dohc cylinder head.

I was just throwing up a link so you guys could check out out and dream about it like I do :P

[Reaper1]

That's a crappy compromise to make to control detonation if you ask me! You loose mechanical advantage on the crank(what makes the torque), put more stress on the rods and pistons due to the accelerated piston speeds, increase side loading of the pistons on the cylinder walls, and you make it harder for the head to breathe properly.

Propper design of the heads and pistons, along with propper tuning will ultimatly yeild more power, more reliability, and an easier to tune engine.

I'm not arguing this approach doesn't work, or that the person that did this doesn't know what they're doing(he obviously knows something!). I'm just saying I think there's a better way.

Yes, displacement helps, but I beleive that good design can take the place of a little more displacement...

[Ondonti]

This is the way to go.

The baddest 6 cylinders all compromise rod ratio.

When you arent building a road racing car it works fine.

If you have 1000+hp and you plan on hitting the gas for more then 10 seconds you are insane.

The cranks were designed as the Crank expert thought was best also.
you cant really complain because the 2.5 TD guys already use a crappier Rod ratio.
The 3000gt dohc heads bone stock flow better then any head I have seen. If you need more breath, just slap on some more duration and port the heads.
Stock they outflow the "AMAZING" Indy cylinder heads for the 2.4L guys.

[Reaper1]

What if I'm not going for a 1/4 mile wonder? I'm going for top speed, and holding close to top speed for a long duration. Specifically Silver State Classic type racing...all out for 90 miles.

I never questioned the DOHC heads, I was questioning the SOHC heads. You've proven what I've thought for YEARS. They have a lot of hidden potential, but you have to work for it. But, they also have their limits. I simply don't see how you could effectively use the 3.7 stroker with our heads and the current stage of development. Please don't take this wrong, I'm at awe at what you've accomplished and applaud you for it! I REALLY want to see it go!

As for the 2.5 TD guys, yeah, I know all about that crappy rod ratio! I'm one of them! I have a plan to fight back and get a somewhat acceptable rod ratio, and have parts to see if it works, but have since come up with another way to do it. I *might* see if what I have works first, but I'm uncertain right now. The major parts are aquired and the major work accomplished, but it's the little things that have held me back. That and the fact I have nothing to put the engine it! My end result will be about 2.4L and will utilize a DOHC PT head. I'd like to see around 700hp on pump gas, but that's a stretch.....

The whole reason we like the 3.0 is because we like to question convention. I'm all for that. For years adding stroke has been "the way to do it". Now so much so that the rod ratio has suffered greatly. This is the way it's done. It's the way the V8 guys do it. It's the way we are copying. What's wrong with questioning that? I've seen some amazing things come from engines that you would never think could make the kind of power they do based on displacement and their origions. The secrets lay in the head, and combustion chamber relationship. Combine that with propper induction and exhaust design and amazing things happen. We all know this, but seem to loose sight of it when we see somebody else already making power the conventional way, so we stop questioning. I don't, I question it. I'm not saying it doesn't work. I'm not saying that it's wrong. I'm just saying I think there's another way, that's possibly better. Note, I also never said it was easier or less expensive! Saying either would be EXTREMELY false!

Anyways, happy 4th! Today I'm greatful I can sit here and discuss things like this and live in realtive freedom...

[Ondonti]

Most 3000gt guys avoid the road race because they have SERIOUS overheating problems. 4000lb and very bad airflow across a radiator which I guess is pretty small.
I dont think we have that same problem. The only heat problem I ever saw was when i went up a 8% grade in oregon for about 4 miles with the turbo on the 3.0.
I was pushing probably 4 psi boost in 5th gear going about 75-80mph (up the 8% grade) and the temps were climbing steadily till I got out of boost. The car weigh'd about 3500lb at the time since I was driving to school again.

If you were doing that kind of all out racing for 90 miles I would just stay stock stroke and bore it out .120" or so.
Not worth the cost of a stroker setup that only gives 0.1L

Those other stroker cranks were just offset grind stock cranks and I dont think that is the way to go with the big ends of our rods.

Most of the displacement gains from that kit were based on using a larger overbore, not much gain'd in stroke.

[Ondonti]

Woooot.

I finally repaired enough electrical gremlins to get the fuel pump working and the starter to go.

In the end I had to permanently ground the clutch safety switch. I couldnt find anythign wrong with the relays or the harness so I just did what is done on my spirit, ground the clutch safety switch.

I have never driven a manual car with a functional clutch safety switch so it doesnt bother me.


I got the motor to turn over without any spark plugs in it about 5 minutes ago.
Now Im gonna put the spark plugs in, dist cap and plug wires. Then fill up the tranny, power steering and coolant.

[Reaper1]

GO BABY GO!!!!!

[Ondonti]

The duster is off jackstands for the first time in 6-8 months :P