94AWDcoupe

iTrader: (125)

a rebore will not be as true as the factory stock bore. factory blocks are machined on equipment that far exceeds your local machine shop accuracy. you can hone a stock block .001-002 over no problem. but even that will be ruining what the factory gave you. I would order shelf stock stock bore pistons and hand sand the top of piston above top ring land. make the piston top .002 smaller will do the trick. its the piston top the expands the most. this way you are not disturbing the factory true bore that will give the best ring seal.

havent you yet noticed how easy it is to make power on stock shortblocks? everything done aftermarket is a step down. this is a much longer conversation. but that is an important bit worth sharing.

batty200

iTrader: (3)

I would also honestly the stock bore on the new block. If you are going to bore a used stock motor is just as good.

badev0

iTrader: (74)

I wouldn't even touch the blocks bore like 94AWDcoupe said. I'm sure you can tell the piston manufacturer a custom spec for your bore.

EvoDan2004

iTrader: (94)

I run the 4 heaviest springs in my tial MVR gates and only see 23psi which is what Tial shows as max aloud wgp. Mind showing me the paper your talking about?

d-bo

iTrader: (14)

Mine was the same as evo dan. Unless you ordered other ones. The ones that come in a brand new tial 44 mvr box only allow 22 or 23 psi

phizzalot

iTrader: (3)

I think 94awdCoupe makes a good point. If you already have the new block then throwing the piston in a lathe to polish/sand down evenly would set more room at top of the cylinder wall... you could even measure the weight after each reduction as well to make the rotating assembly a little lighter.

batty200

iTrader: (3)

Tom has a single scroll and you have a twin scroll right Dan? I think you having dual waste gates prevents boost from being higher. My single wastegate runs higher boost than the springs. I hit 27-28 with "23psi" of springs and a friends car hit 38psi on the same springs. Both TiAl V44 waste gates.

batty200

iTrader: (3)

Wiseco already makes stock bore pistons. If the block is new there isn't a need to mess with the home either because it will have a perfect cross hatch too.

tscompusa

iTrader: (31)

Ya mines single scroll vband. I also have very large runners on the manifold & im forward facing. I run 31-32psi on wastegate pressure. Steve has almost an identical setup to me, but hes on smaller runners and standard placement and his wont go any lower then 26psi.

I don't think i have those paper anymore Dan, but ill check for you in the drawer where I kept the springs.

Ya I ordered stock bore pistons from Wiseco. I'll mic piston when they come and check bores with a dial bore gauge and see what I got. I suspect its gonna be around whatever is preferred from wiseco on paper.

The block came today. Heres a pic of it.



Also I appreciate the insight and knowledge guys. Thank you!

I had .010 pistons ordered, but canceled them now. I have standard on the way now.


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Also if anyone's interested in that Blue evo I have I am gonna let it go for 25K firm. i want to pick up a 13' GTR. I will keep my silver evo and have the GTR also.

The Silver evo i will keep for the rest of my life. For me the GTR will be an investment, since it will be another platform I can tune.

SLVRNBLK

iTrader: (169)

Just curious Tom, are you going to use a stock HG?

tscompusa

iTrader: (31)

With the 4g63 yes absolutely.

tscompusa

iTrader: (31)

I'll keep this short and sweet (or not (I tried to but couldn't) since I am still behind on tuning customers cars.

I need to bolt the torque plate on the 4g63 block with my 625+ ARP studs. If the bores dont distort and stay straight then ill use the existing work from mitsubishi. If it distorts then obviously I will straighten it out.

Now onto the 4g64 / 2.4L:

I dug into the engine more then I originally anticipated on doing mainly because I was "curious" because upon assembling this engine i didn't really do to much measuring. Only used plastigage which is trash and anyone who uses it is not a engine builder and should never be called one. I am sorry if that offends others. That includes me also when I used to use it.

So lets start with the good first. Here are the rod bearings from running anywhere inbetween 750whp to 800whp, with 300 miles on SAE straight 30 weight oil only. This oil should only be really used for seating rings, not going out and beating on the car, because if your clearances are on the loose end you certainly dont want thin oil as a cushion when pumping 250hp per cyl.

Rod bearings looked perfect almost, minus one rod that looks to got some dirt in there.

Pics below of rod bearing stuff:







Moving along:

Here is where it gets good (not really). actually its quite bad, and its because I didnt have the knowledge before that I now have now.

4g64 blocks are NOT like 4g63 blocks. if you run STD bearings in the mains and make big # you are going to eat bearings quick. May still survive, but its not proper wear. The 4g64 has a tighter main then the 4g63 from the factory. If you have the measuring tools i have you have the ability to see this clear as day.

Either way here are the mains with STD bearings. And no the 'lower halves' are not supposed to be wiped clean like they are in the pics. The upper's did not look to bad but still more wear then id certainly like from only 300 miles of abuse.

uppers:



lowers:



You have two options.

1. you can get extra oil clearance bearings and run just one half .0005" more then the other which is perfectly fine and ok to do granted you can measure down to .0001" and monitor what you're doing.

2. or you can get a line hone and open it up some. I am just going to run a half set of extra oil clearance to set me where i want and be done since this engine is not going to be in the car for much longer.

Just for reference on a 2.244" main journal diameter you certainly dont want to be anywhere near .0015-.0016" which is what standard bearings set you at.

The rule is .001" per each inch. so using that we come up with roughly .0022"

Now on a high performance app you may wanna go alittle more. up to .0005" even which would set you roughly around .0027" alittle loose for my taste on a main but a hell of a lot safer then .0016" when pumping 250hp+ per cyl

halves will put me right around .0023" ish or so on my particular application, which should be right where i wanna be.

I am putting the 2.4 back in temp with fresh bearings while I get the 4g63 ready. I am going to order custom pistons for it also to around a 10.1 compression.

Also upon further review and multiple others giving advice we come to the conclusion the crank was flexing as well, putting uneven load on bearings as you can clearly see by the bearing wear. Im switching to the standard weight billet crank since I plan on making big power temp with this block once its back in.



I guess thats it for now. Will update later. Once this is back together I am gonna get it around 800whp+ and run it down the track and get a time before i take it apart then i will run the 4g63 block & this block will be for sale.

Jwhalen07

iTrader: (6)

How many 64 blocks have your measured to make the claims the 4g63 having a different main housing bore size? I have measured many(mostly 4g63's) and most of them do not hit the number on the 0 out of the box regardless if it a 63 or 64... I believe your main problem is your slinging a 100mm crank around. To prevent main problems Kiggly welded on something like 20lbs to the 100mm crank to calm down the harmonics plus an array of other tricks he has learned over the years.

That is why the 2.0L is so popular in the drag world by the top companies. The 88mm crank has much less harmonics to deal with, better rod/main overlap making it overall a stronger crank, ect, ect.

Not trying to argue with you but push your mindset possibly in a different direction.

tscompusa

iTrader: (31)

Its fine I don't mind you questioning it.

Over 10. They are all tight vs 4g63. check for yourself next time you get a hold of one.

4g63's all are around .0019-.0022" (out of the 15 or so ive done so far)

If it was only crank flex the lower bearings wouldn't be wiped down to the 2nd layer in 300 miles like they are.

I've tore down engines with 5000 miles and the outer layer was still intact on both upper & lower. Not the case here.

Also with .0005" half shells i got a consistent .0021-.0023" last night on this block in 70F temps.

If you half shell a 4g63 you will be in the .0027"~ area on every bore 99% time.

No doubt the crank flex isn't helping though. the crank was polishing the bearings from flex you can see it.

I'll update the thread in a little bit with some more pics of my progress.

Technically i think minus the crank flex the mains would of survived no problem, the engine just wore its own clearance in, but that's not really the right way of doing it! as we both know.

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Also keep in mind the specific clearances i mentioned above are with the Manley crank. Other cranks will vary of course.

Jwhalen07

iTrader: (6)

Right on man. Interesting and good information.