mchapman

iTrader: (1)

I found this in the FI forum:
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I emailed Darton and this is the response:

"We do have a MID kit for the VQ35DE. It is a closed deck design that comes at the standard bore of 95mm and has a max bore of 100mm. The kit retails for $1075.00 plus shipping. The sleeves are custom made to order. "
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So there are some overbore sleeves out there.

With these 100mm sleeves and larger pistons the VQ35 would become a VQ38. (Obviously you would get larger high compression pistons if you were sticking to NA.) The stroke isnt increased so you dont have to worry about increased friction. Which means if you were planning on increasing the revs you still can. Changing the rod bolts or upgrading the rods might also be a good idea while you have the motor apart.

RQ1Driver

iTrader: (1)

The sleeves are standard bore and after they are installed the sleeves are honed to match the pistons. so if you had standard pistons the displacement would be the same. They are just giving the upper limit before the sleeves are too thin

mchapman

iTrader: (1)

Ok so I have to buy them and bore them out to 100mm.

I cant get them already bored out to 100mm from Darton? They custom make each order?

Nathan

Murray
Why dont you price the AEBS 101.5mm sleeves with the 11.5cr pistons. With the stock crankshaft this conversion would be a
3949cc motor & those 11.5 cr pistons would now be 10.51cr just right for our 98ron fuel.
You would have to use Pauter rods with extra drilling for under piston oil supply as any sleeve up around 100mm would interfere with the stock squirters.
The AEBS stroker kit uses drilled Pauter rods & blocks off the original squirters, but you could not use those rods as they are designed for the longer stroke.
I am getting excited writing about this as I would estimate with a set of cams& headers & an 80mm intake pipe it should make a very reliable 360 to 380 HP now thats Porsche & Ferrari teritory

mchapman

iTrader: (1)

Originally posted by Nathan
Murray
Why dont you price the AEBS 101.5mm sleeves with the 11.5cr pistons. With the stock crankshaft this conversion would be a
3949cc motor & those 11.5 cr pistons would now be 10.51cr just right for our 98ron fuel.
You would have to use Pauter rods with extra drilling for under piston oil supply as any sleeve up around 100mm would interfere with the stock squirters.
The AEBS stroker kit uses drilled Pauter rods & blocks off the original squirters, but you could not use those rods as they are designed for the longer stroke.
I am getting excited writing about this as I would estimate with a set of cams& headers & an 80mm intake pipe it should make a very reliable 360 to 380 HP now thats Porsche & Ferrari teritory

I will contact AEBS but I believe that they want to install the sleeves themselves and I dont want to fork out for another block supplied by them. I'll see what they say though. Fingers crossed.

Wouldnt the compression stay the same, as the rods are only longer to make up the distance from the longer stoker crank? Meaning the pistons would still go up to the same location, leaving the compression at 11.5:1. AEBS does offer 11:1 compression pistons.

Doesnt the M3 run that compression safely on our fuel? Do you use normal fuel for your race car?

I believe you can get Pauter rods with the holes already drilled by Pauter, but at an additional cost. I doubt it would cost much more.

Yeah the power gain should be good and with these sleeves, pistons, rods and cams you could increase your RPM a decent amount giving alot of power up top and still maintain a very good bottom end because of the extra displacment.

VQ39.5

Nathan

Murray
No the CR would not stay the same.
CR is the swept volume + the unswept volume divided by the unswept volume. That is the volume of the cylinder plus the volume of the combustion chamber piston cutouts ect, divided by that same amount.
As the stroker AEBS unit is over 4.3 litre the volume of each cylinder is bigger but the combustion area remains the same.

I have just realised that the stock squirters are problem because of the increased stroke & may not be a problem with the larger bore.
Ring me and I,ll tell you what questions to ask them.
I've got three VQ 35 engine blocks one of which needs sleeving

mchapman

iTrader: (1)

Note: I should have written rods are shorter, not longer, for use with the stroker crank.

mchapman

iTrader: (1)

Peter, please check your PMs.

mchapman

iTrader: (1)

Incase anyone else is interested in this, I spoke to AEBS about using their sleeves and pistons with stock 'spec' rods to create a VQ39.5 as suggested by Peter, with the same stroke as the stock motor. And it can be done.

AEBS 11.5:1 Pistons:US$1150
AEBS Sleeves: US$120 each x6
AEBS Gasket: US$80
Rods from Someone: ~US$1100
Fuel Pump from Someone: AU$200
Getting the sleeves installed here: AU$1000
Getting the engine put together: ~AU$2200+ (Very Ruff Guess)

Basically with all this you would have a very strong engine, a slightly higher compression 10.5:1, a ~12-13% increase in displacement and it would be capable of higher RPM when combined with cams. An ECU solution would be necessary to tune all of this.

Note: For the prices of the AEBS parts, I mentioned that there would be 3 possible buying interests, but I think price didnt change and is for a once off purchase. Not sure though.