Stroke, bore, and motor integrity questions

[Weou09]

I'll probably be tearing it down once a season anyways. This is, after all, a race car.

If it is going to be that serious I'd bet you could do certain things to make that extra 80lbs work to your advantage or at the very least negate it. What are your plans for the chassis? Suspension?

 

[Dubstep Shep]

I will confirm with you the following, even though a completely different motor the principal is the same.


With my motor setup, we determined the 4.5 stroke was the maximum just for that reason, as we felt with the 4.75 stroke the piston skirt just came out too far, which would put excessive wear on the piston skirt.

Also, piston speed becomes a factor which you can not ignore, based on your expected rpm range. In my case 4.600 bore X 4.500 stroke = 598 cid with a maximum expected rpm of 8200 but peak power probably 7600 or so. Don't forget your rod/stroke ratio can affect the cam specs you may want to go with.

I probably won't be spinning it that fast. I am planning on a new engine management system at some point, so it would be possible, but I would rather have a ton of low end torque than higher power. That was one reason I would like to have a longer stroke. I do see where the piston skirt could be an issue.

That said, I'm looking at my current motor and part of the skirt is hanging down under the sleeve.

The OEM short block I have has the pistons no where near the bottom of the sleeve. now I'm wondering if my builder accidentally gave me a stroker crank lol. He forgot to bill me for my valve springs so I wouldn't be surprised.

If it is going to be that serious I'd bet you could do certain things to make that extra 80lbs work to your advantage or at the very least negate it. What are your plans for the chassis? Suspension?

Griggs full suspension. Full cage. At some point I plan on swapping steel and aluminum panels and what not for carbon fiber. The Griggs setups weight savings should offset my blower and manifold, or at least get me in the ballpark. stripping the entire interior, deleting heater and AC. Lexan windows. Etc, etc.

Also its worth noting that if I do cryo and WPC everything, wear will be a very small concern.

 

[eighty6gt]

I can't wait to see this build - I was just over checking a similar one in the 4.6 tech forum. It's unreal how much money you can bury in a car that has variants at a $20,000 price point!

 

[Dubstep Shep]

I can't wait to see this build - I was just over checking a similar one in the 4.6 tech forum. It's unreal how much money you can bury in a car that has variants at a $20,000 price point!

I'm already 60k deep in this car including the original rebuild when we bought it wrecked, not including the 10k for the R-spec. I'm looking to drop another 10k on brakes and a full floating setup, a few thousand on an axle, plus 10k finishing up my griggs setup. I've also got a few thousand to spend on a cage and wiring harness through Vorshlag.

No idea what this next motor will cost, but I would guess at least 20k. Probably closer to 30k depending on which route I go.

If I can make it out the door under 150k total, I'll be happy. The money isn't important at this stage. This is about building a car I can race in anything and do well, and learning more about everything.

Once I get settled into my permanent position this summer I'll probably start a build thread. Right now I'm saving as much $$$ as I can.

Talked to Darton today. They confirmed most people go with a 94mm bore and it's MUCH stronger than the factory setup. They also said they've had zero failures when they do the installation, and there is a lifetime warranty against manufacturers defects on the sleeves and one year warranty on the installation. Not too bad.

I emailed them back to see about some specifics. Prices, what they recommend for other stuff like clearances and what not. I'm halfway tempted to let them do all the machining on the block since I'll have to ship it to them anyways...

Can anyone tell me if GT500 4v heads will bolt up to the 3v block without modifications of the oil and cooling passages? What about the 4v terminator heads?

Reason I ask is the guy mentioned something about having to modify one of the oil passages in the head to work with the sleeves. He said the 4v heads are correct, but idk if he meant the terminator or GT500 heads. I asked him to clarify but I want to double check here.

 

[Sky Render]

I've got nothing to add other than for the suspension, I would spec out GT500 front dampers and springs to deal with the added front weight.

 

[Dubstep Shep]

I've got nothing to add other than for the suspension, I would spec out GT500 front dampers and springs to deal with the added front weight.

I'm way ahead of you brother.

When I get around to doing my Griggs SLA setup I'll have them spec me out the exact setup I need based on everything else.

 

[Pentalab]

Can you even use anywhere near that power....for autocross, even dialed down ? Depending on the layout of the track, the few I have seen, are not really hp type circuits.

With the power dialed way back, will it run ok, for a 30 min track session, in hot wx ?

 

[Dubstep Shep]

Can you even use anywhere near that power....for autocross, even dialed down ? Depending on the layout of the track, the few I have seen, are not really hp type circuits.

With the power dialed way back, will it run ok, for a 30 min track session, in hot wx ?

I won't be using the full power for autocross. I'm pretty sure I've said that a few times lol. That said, there's no such thing as too much power in my book, only a foot that's too heavy.

Gmitch (DOB) has a car with the 3.4L whipple that he runs road and track races in. Zero heat soak issues because the R-spec has the best cooling capacity of any manifold out there. Hence why I'm using it.

I really didn't make this thread to debate the merits of the R-Spec manifold or where I should use it. That decision is made. I'm merely trying to figure out if I can make Gmitch eat his words about me never needing a 4.0L whipple hehehe. But before I can do that I need a motor that can max out the 3.4L whipple.

 

[Weou09]

I won't be using the full power for autocross. I'm pretty sure I've said that a few times lol. That said, there's no such thing as too much power in my book, only a foot that's too heavy.

Gmitch (DOB) has a car with the 3.4L whipple that he runs road and track races in. Zero heat soak issues because the R-spec has the best cooling capacity of any manifold out there. Hence why I'm using it.

I really didn't make this thread to debate the merits of the R-Spec manifold or where I should use it. That decision is made. I'm merely trying to figure out if I can make Gmitch eat his words about me never needing a 4.0L whipple hehehe. But before I can do that I need a motor that can max out the 3.4L whipple.

Not doubting the r spec, but doesn't he have a crazy custom cooling setup?

 

[Wes06]

Your talking to Shep. Of course he's just as crazy

 

[Dubstep Shep]

Not doubting the r spec, but doesn't he have a crazy custom cooling setup?

Indeed, and I'm planning on one upping him. He still has his A/C. I'm removing mine

Your talking to Shep. Of course he's just as crazy

Bingo!

 

[05yellowgt]

Did you talk to Darton about the length of the sleeves? I believe that they can be made to keep the piston skirts from protruding out of the bore, but I think that might limit your stroke options. Just something else to consider.

 

[Dubstep Shep]

Did you talk to Darton about the length of the sleeves? I believe that they can be made to keep the piston skirts from protruding out of the bore, but I think that might limit your stroke options. Just something else to consider.

I'm not sure if that's possible with the MID sleeves, but I went ahead and asked the guy. I'll chime back in with what ever he says.

I also got final pricing. The sleeves are $1400.00 for the set and labor is an additional $1175.00 through Darton.

Additionall, there is a little bit of machine work required on the heads. One of the oil passages needs to be modified to match the GT500 head design. I'm trying to get a hold of diagrams of both heads to determine exactly what's required.

 

[ford20]

The Darton Hat Style Sleeves I have going into my car are going to reinforce the block and reduce deflection and help with the strength and integrity of the block. Just as a reference they were $3500 to buy and install on a 5.0 so you can use that as a rough estimate for you and that is with a stroker crank.

 

[Dubstep Shep]

The Darton Hat Style Sleeves I have going into my car are going to reinforce the block and reduce deflection and help with the strength and integrity of the block. Just as a reference they were $3500 to buy and install on a 5.0 so you can use that as a rough estimate for you and that is with a stroker crank.

Interesting, thanks for the info!

 

[v6tungsten]

Expensive from what I can tell. Sleeves are like $1,400 I think, plus installation, which I would be letting Darton handle. I have no idea how much installation will run.

Yea, having a 334 cubic inch motor would REALLY bring out that 3.4L whipple. Plus having a 3v that big with that much power would be AWESOME.

My vote is sleeve current 4.6 aluminum block. you are already going to spend 10k on the supercharger kit. why be cheap on the block.

 

[Dubstep Shep]

My vote is sleeve current 4.6 aluminum block. you are already going to spend 10k on the supercharger kit. why be cheap on the block.

That the exact reason I'm looking at the MID sleeves. I'll take anything at this stage that may add some strength to the 4.6 block. I'm probably going to add some external bracing to the motor and chassis at Dartons recommendation as well.

 

[v6tungsten]

SSPSTANGBANGER has custom Barton dry sleeves not MID sleeves for his block

 

[s8v4o]

Dude, just sleeve an aluminum 5.4 or get the GT500 5.8L block

 

[Dubstep Shep]

Dude, just sleeve an aluminum 5.4 or get the GT500 5.8L block

I hope you're kidding...