Internals for SR20DET - decisions decisions

[Tom Ngan]

So I'm deciding to build my SR20, since its out and its ready to go in.

I'm shooting for at least 350rwhp.
I have HKS 254 cams, greddy IM, greddy 1.6mm HG, GT2871R .86


I have a couple questions.

1)What kind of pistons/rods combinations should I go for?

2)I'm unsore of the choices in pistons that I should pick, bore size? compression? Which would be best?

3)If I choose a certain bore size ie. 86.5mm and the stock bore size is I believe 86mm, I would have to bore out the block correct?

4)I'm commissioning a shop to do the internal work on the motor, what should I expect in terms of man hours to do this from a competant mechanic?


I first wanted to just have the rod bearings replaced and keep the stock rods and pistons, but I'm tempted to get them all replaced as well.


Any advice? Opinions? Experiences? Anything extra I should ask about or know about?

THANKS guys!

[MomentumGT]

Sounds like you 're planning a pretty nice build up, but shooting for 350whp is pretty low for you to do all that work, unless you just want to. Stock should be able to handle just fine.

-Jon

[johngriff]

If you are going to go aftermarket pistons, alter the compression or bore. Otherwise stock with new rings is good.

Rods is a matter of opinion, but if your OEM rods are not warped, i would say keep them.

Building it could be anywhere from 10 hours to 100 hours depending on what work is done. It sounds like it is more about budget to you.

[Wahl 136]

I have a couple questions.

1)What kind of pistons/rods combinations should I go for? Mahle/Eagle

2)I'm unsore of the choices in pistons that I should pick, bore size? compression? Which would be best? 8.5:1 86.5 std

3)If I choose a certain bore size ie. 86.5mm and the stock bore size is I believe 86mm, I would have to bore out the block correct? yes cost me $190

4)I'm commissioning a shop to do the internal work on the motor, what should I expect in terms of man hours to do this from a competant mechanic? 2 weeks down time for me.


I'm running those internals, HKS 262/272 Step 2's, gt2871r .86, yadda yadda yadda.

[Tom Ngan]

Thanks for the quick responses guys.

Budget to an extent, I'm willing to fork over maybe 4-5gs in labour alone, another 1-2gs for the pistons/rods/extra parts.


Just wondering if its a reasonable ballpark. So far the shop said they will do the KA swap to SR, rewire standalone installed, tuned, and put on all the goods including cams/head work/replace rod bearings, plus ETC for about $1800-2000USD. Which I think is pretty reasonable....

[Wahl 136]

Thanks for the quick responses guys.

Budget to an extent, I'm willing to fork over maybe 4-5gs in labour alone, another 1-2gs for the pistons/rods/extra parts.


Just wondering if its a reasonable ballpark. So far the shop said they will do the KA swap to SR, rewire standalone installed, tuned, and put on all the goods including cams/head work/replace rod bearings, plus ETC for about $1800-2000USD. Which I think is pretty reasonable....

Ixnay on the labor cost. Shop around I had my machine work done for under $500 and that's having the hone redone, I can't image the shop charging that much more to reassemble your engine for you. The piston/ring/rod set is exactly $1000 that I listed.

[Tom Ngan]

Being in canada doesn't help the costs, items crossing the border and customs is a huge blow to the wallet.

What kind of power are you putting down on your setup?

I can only do little things on my own, I have no avaliable time right now to build and swap an engine. That was the plan, but getting that second job wasn't =(

Well these are the quotes my shop gave me:
(Prices in CDN)
20-22hours of labour @ $70 for....
-KA swapped to SR20
-install manifold, clutch, rod bearings, FMIC, turbo, injectors, oil pan, water pump, ETC

Probably cost alittle extra for the HG installed with machine work on head for cams ie. $400-500.

So i'm looking at $2000CDN roughly.

Would wiesco pistons or CP pistons be any good? So stick with the 86.5mm? Any other corresponding parts that I should look into while the pistons/rods come out?

[johngriff]

Ehhh, almost any piston is going to be the same. Stick with OEM 86.5, if you are going to pay for custom forged, get a larger bore or raised compression.

[Tom Ngan]

Would a higher compression piston mated with a HG that lowers compression be a problem?

I'm thinking 9.0 CP pistons or something along those lines....

[yaba94070]

did you search for this question cause i just did this thread... and about 10 other peopel did it but its kind of unipue i guess because your asking about compression but thats the only realy diffrence.
I am doing the same build but going for way more HP.
Just to let you know my opioun CP piston is probally the best bang for your buck, and im going with crower rods but if you want some thing cheaper go with eagle rods there about $200 cheaper. I am blancing my block and getting it blue printed and my pistons are 87.5 mm and i am boreing the block out to that. I have a built head though so theres a lot more. I alos repalced prity much every thing though so i spent a lot more money. Put i figured if im going to take apart the block i mise well save up and go all out on it so i know every thing is brand new. PM me if you want the mod list for the intrenals or any info or what exactly i am doing i would be glad to help with what i can... I am kind of new dealing with SR20s but i have been doing research for 6 months and found out almost every thing there is to know about them. All i can stress to you is oil oil and oil. Get and oil cooler and catch can jsut in case it will be the best investment ever rofl. I ended up getting rod knock on my last block because of an oil issue. So on this build i bout a new oil pump, oil cooler, oil catch can. and i already have the greddy oil pan.
good luck let me know on anyhting else

[yaba94070]

i will let you know on how much my entire motor build cost for the botom end. the esemate isa bout 5000 - 6000 but i keep adding parts so we'll see. I will keep ya posted.

[johngriff]

The Headgasket thickness will not effect compression all that much. I would use the APEX 1.1 if you are going to use stock bore.

Other wise your up the cometic creek, which wont be that bad because you'll have the block decked.

Http://www.rpsportengineering.com <-- a look into my 2.2L 9.5/1 SR