Mitsubishi EFI V8 Closed Deck Alloy Block 2mm Dry Iron Sleeves, how to replace or bore?

I've imported a mitsubishi V8 I found in korea. its a Transverse 4.5L DOHC V8. I'm planning on putting a decent sized turbo on it, lowering the compression (from 10.7 to something boost suitable) and going forged internals.

I'm in the process of figuring out a torque plate for honing the cylinders. however, it's an aluminium block with 2mm dry iron liners (sleeves). I want to know if I need to remove the sleeves and hone and then put in new sleeves, or if I can just hone the sleeves. The motor still has it's machining marks in the bores, however with new pistons it was recommended I go 1mm larger and rehone due to factory blocks usually not being perfectly cylindrical in the bores.

What do I need to do!

Cheers,

Lindsay

It all comes down to the thickness of the sleeve that will remain and your intended power level. Personally I wouldn't want to reduce the sleeve thickness below 2.0 mm if you're aiming for serious power. This gives you the option of using pistons that will only require a light hone of the existing sleeves, or fitting thicker aftermarket sleeves which may be a huge task with an engine that isn't well supported in the aftermarket.

Thanks Andre,

I did some more measuring of the sleeves and realised that the advertised 2mm isn't actually correct. they're around 3.5mm thick each.

A mechanic mate recommended getting a torque plate made up and thought that with new ARP headstuds I'd need to hone the block to bigger than standard to ensure a cylindrical hone for new forged pistons.

Also looking for recommendations on where to go for rods, pistons. but i'll watch all the course material before I get into that stuff so I know what to ask.

Thanks again mate!!

Cheers,

Lindsay

We're just getting into a GM LS1 build where it's not possible to bore the block due to sleeve thickness. in this case we have a set of Wiseco pistons specifically for this block that just require the block to have about 0.003" of material honed out. This retains as much strength on the block as possible but provides a fresh honed bore for the rings to bed against. Granted this allows little to no scope to rectify any out of round or taper though.

With an unusual engine or one not common in the aftermarket, your only option may be to have custom parts made for you. This shouldn't be a problem but will cost you more than shelf stock parts.

Thanks heaps for the advice Ben! As it has 86mm bores... I’ve been looking at 86mm pistons, but I realise there’s a lot more to it than just bore size. I need to think about compression, pin size, skirt design etc.

as it’s a 4.5L... and it’s a Mitsubishi. I was wondering if a 2.2L stroker kit for an Evo (x2) would work? With a V motor is the piston design different due to the angles of the rod off the crank? or is there just too much involved in it and I’d be better off going with a custom set up?

I just thought it would be cool to have a V8 with Evo forged internals... which is probably ridiculous. It does have a forged crank from factory that I hope it up to scratch for the job.

Also looking for a machine shop to do my machining atm. Wondering if I get a light hone first to make sure the bores are round. Then look into pistons from the outcome?

Cheers heaps mate!

Your first problem is that the crankshaft is the key to a stroker kit, so you're not obviously going to be able to utilise a inline 4 cyl crank in a V8 engine block. The pistons and rods 'may' fit but I'd be very surprised. I'd almost guarantee that you'll need to consider custom parts if you wanted a stroker kit, however it's possible that 4G63 aftermarket pistons may be compatible. You'd need to confirm compression height, wrist pin diameter and crown profile/valve pockets though first and foremost, and then consider the impact on the compression ratio.

Thanks Andre,

I definitely won't be able to use an evo crank. haha! The engine has a 96.8mm stroke and an 86mm bore. so if anything it'd be a de-stroker kit!

In researching the piston and rods from the stroker kits, I've found that some of the piston/rod combinations may be correct. I need to look into them a bit more and also ensure the big end is the right size as well.

If I was to use 8x evo pistons, you're right! Chances are i'll need custom rods to suit them. alternatively I could just go for custom for both, as price wise, a custom set of 8 won't be much more than 2 sets for an Evo. (good old evo tax)

who would you recommend sourcing them from if I did go that route?

There's so many brands out there- Wiseco, CP, JE, Ross, Supertech, Ross, Manley.

I'm also wondering if I could get sponsorship for a build like this? It is a one of a kind engine and no one else has ever built one before. I think it will get a fair bit of attention moving forward, and I'd happily promote products I use. But i'm unsure if it'd happen? Or, who would even be interested.

Cheers,

Lindsay

You do need to be careful of the crown profile and valve pockets if you use a set of pistons from a different engine as there's almost certainly going to be some differences and this will affect clearances to the valves as well as the final compression ratio. I'd imagine any of the mainstream piston companies would be happy to work with you on something custom. Personally I used JE through our drag engines but I don't think you'll find much separating the popular name brand companies - Forged piston technology is a relatively mature industry sector now and there aren't too many large advances in technology.

By all means it may be worth approaching a company for sponsorship, however without some existing achievements it can be very hard to get companies to take an interest.

Thanks Andre,

Cheers for all your help. I will try for some Sponsorship, and you're right about having previous achievements would help towards that a lot. I have an Audi A4 with a fair bit of work done to it that I've been meaning to get into some track days with. So I might explore that a bit more and look at developing some good contacts in the industry here.

I'm not in a huge rush to get the build done. I want to take my time, use good quality products and create a well rounded build that is competitive through a range of Motorsport areas. The Legnum shell isn't really that heavy and this motor is quite a bit lighter than the standard V6 as well as having a lower centre of gravity. I'm thinking it will have some very favourable power to weight ratio outcomes once complete and will be fun for drags, track, hill climb and a weekend car. Which I know is a lot to ask for from any car.

I was planning on keeping the build relatively quiet. but maybe making a build page on instagram, facebook etc and getting some followers would help me to get Sponsorship.

Cheers

Linds