Sleeving out to 3.8" possible?

Greg55_99 · Post by **Greg55_99** » Sun Dec 16, 2007 2:29 pm

Just wondering if it possible to sleeve a crossbolted block out to a 3.8" bore... and have it live in a street car. An ideas?

Greg

Post by **katanaman** » Sun Dec 16, 2007 2:47 pm

I know 96mm is done via top hat liners which is 20thou less than your looking for. That said there might be a rebore of 20thou on top of that which would put you pretty much bang on your 3.8". What pistons and all that are available I have no idea but V8 development would be able to tell you. Not a cheap option for sure when you can probably go along the street and get an LSx engine.

CastleMGBV8 · Post by **CastleMGBV8** » Sun Dec 16, 2007 3:24 pm

Greg,

The largest liners I've heard of for the Rover Block are 96MM which is 3.78" which is fairly close, ther obviously must be pistons available to fit this bore size which would give you an engine of just under 4.8L with a 4.6 crank at 82mm

V8 Developments above do the liners so you could ask them about pistons or try Dan Lagrou D&D Fabrications inthe US.

Link http://www.aluminiumv8.com

Kevin.

Greg55_99 · Post by **Greg55_99** » Sun Dec 16, 2007 4:13 pm

Thank you Kevin and Marki,
I'm asking about this because another gent and myself were kicking around a "feasibility study". That is, just how much displacement can one get from a Rover motor using off the shelf parts. Some info can be gleaned with this data:

Block: Crossbolted Rover V8 sleeved to 3.7992"
Pistons: Hypereutectic from the Buick Supercharged 3800 V6
Crank: Cut down Buick 340\350 to 2.5" on the mains.
Rods: Stock Buick 300 bushed to take 3800 V6 pins
Intake: Welded Steel single plane with injector ports
Cam: TA Performance modified for Rover V8 cam bearing size.
Fueling: Megasquirt
Oiling: Range Rover front cover with gerotor oil pump driven off of the crank.

When you do the math

Rover V8 deck = 8.96" (or thereabouts)

Buick 350 stroke = 3.85"
Buick 300 rod = 5.96" ctr to ctr

Let's see now: 3.85\2 = 1.925"

1.925" + 5.96" = 7.885" - 8.96" = 1.075" left for the piston. The Buick 3800 V6 piston is pretty darn close at 1.09"

http://kb-silvolite.com/spistons.php?ac ... s&S_id=521

If you destroke the crank 20 thou, that might make something like this possible. Works out to about 347 cid. Of course, for us over here, the larger problem is getting a set of heads that will support an engine that big. Wildcats are out of the question due to the current exchange rate. TA Performance is promising alloy heads for the Buick 350 which can be made to work, but, have thus far, not materialized.

So, it's just a study...

Greg

Post by **katanaman** » Sun Dec 16, 2007 7:55 pm

The biggest I know of anybody doing on a standard block is 5.3 or 323ci and that's with people casting their own crank. Most actually stop at 5.2 but they maybe aren't using top hat liners. Not saying it cant be done but there must be a reason that others aren't doing it. Maybe there isn't enough room for the crank to clear or something?

HairbearTE · Post by **HairbearTE** » Sun Dec 16, 2007 8:20 pm

When I popped into Rpi they were just putting together a 5.5 for their morgan. I'm sure it was a top-hat 4.6 block and not aftermarket. I calculate that a 96.5mm bore and one of Mikes 94mm stroke cranks would be required to achieve 5497cc. Maybe that's how they did it?

Boosted LS1 · Post by **Boosted LS1** » Sun Dec 16, 2007 8:37 pm

^ That sounds about right as I know people have used them to make 5.5 litres so they could be a few cc under that. I can cast them easily enough but grinding takes forever.

To the OP, have you thought of alloy buick 300 heads or at worst the iron 340 heads.

Either would get you going. Also you could use D shaped trw pistons from the 96mm pinto engine. Machine a full dish and you get 21cc iirc. Combine that with an offset ground 4.6l crank and you get a 5.1l turbo motor:) You need the 300 heads though for this conversion. I once did a 5.4 with an offset crank and 94.5 mm bores or thereabouts. It used fuelli 327 rods but I can't recall what the pistons were. They would have been off the shelf yank items though for repeatability.

chodjinn · Post by **chodjinn** » Mon Dec 17, 2007 10:00 am

is there any way of getting more than 4.6 without grinding the crank?

I have a 4.6 block that needs relinering and i dont know what size liners to go with at the moment.

ChrisJC · Post by **ChrisJC** » Mon Dec 17, 2007 1:05 pm

I would have thought that given all the block cracking issues with the 3.7" bore engines, that enlarging the bore would be a bad idea?

Chris.

chodjinn · Post by **chodjinn** » Mon Dec 17, 2007 1:11 pm

I think that the 96mm top hat liners can be bored out to 96.5mm by the sounds of it, so not putting any more stress on the block compared with 96mm as you still have to machine the same amount out to get them in, is that right?

*edit*

Just spoke to V8D - they are officially awesome

Not really worth me spending the money on 96mm liners or fancy pistons or anything really. They advised me to get 94mm liners, keep the standard rotating assembly, and if i melt a piston, i can then have it bored out and forged ones fitted at a later date.

Exactly the opposite approach to DJE, who generally aren't interested in even giving advice unless you're waving a wad of cash at them. I know where my money is going in the future: V8D all they way.