NA build question

[sickocb7]

ok so ive tried searching through numerous threads and cant really seem to find my answer.


what oem pistons will give a nice bump in compression, if there is any?

im just looking to build a reliable DD with saving some money.....im looking at 85 or 86mm bore

ive heard k20 pistons work!? maybe h22? or usdm h23 pistons?

any answers are welcome!

[wed3k]

Ive been trying to figure that one out as well but none atm. its not like a vitara drop in for your D15/d16

here's the options:

1.F20b piston and cut the deck .020

2. RS engineering's B20B domed piston .040 over = 85mm
need to rebush the rod to run the smaller wrist pin or hone out the piston

3. K20 piston but also need to rebush the rod for the smaller wrist pin but the K20's are designed to run in the opposite direction.

[Father Time]

you could also find someone selling some JDM F22B DOHC pistons. They are 85mm and have like 9.2-1 compression.

[HondaFan81]

First of all, I assume you have an F22ax. Here are my suggestions:

1) Get a JDM F22B DOHC good condition block assembly for cheap or good condition pistons from same application. This will increase CR from 8.8 to 9.2. This application retains 85mm piston bore.

2) Milling an F22ax head .020 inches will yield a 0.2 CR increase, but you should get an adjustable cam gear to set your physical timing properly. Doing this tip, plus #1 will approx. increase from 9.2 to 9.4.

3) Buy Bisimoto 86mm bore piston kits at 10.5 or 12 CR for a very reasonable price ($459). The kits come with pistons, rings, wrist pins and locks.


NOTE: Regardless of the mentioned, check ALL options and price them out. Then, compare and see what is the best bang for the buck at a price you can afford!

[SOHCinWA]

IMO .. I would go with the 3rd option. This will give you a forged piston that will handle just about anything you decide to throw at it later. If you dont have the funds at the moment, you may want to wait a little while until you do. It is worth the investment in the long run.

[sickocb7]

thanks guys! overall i dont think i would be save that much money, and i dont really like the idea of cutting corners especially when it comes to a motor build! i guess its time to start saving!!!!

[wed3k]

or you can just run with some k20 oem pistons.

its not cutting corners, it's called being on a budget. plus you dont need a forged piston for 200hp.

[HondaFan81]

SOHCinWA,

I was thinking the same, but wanted to throw other options.

I believe that when you do all the calculations to compare your options and determine what is the best bang for the buck, the Bisimoto piston kits will be the choice.

Remember, options #1 and #2 will cost money, but you will only gain a few points in CR increase. I think the 10.5 CR Bisimoto piston kit will suit you nicely and will yield the best bang for the buck.

I think many people fail to realize that to even make OEM hybrid setups work, IT WILL TAKE MONEY and well planned execution. Nothing comes for free! You may save some money, but it will probably take you more time to make sure it all works out together and much trial & error. Sometimes simplicity is the best option and when it gives you more CR increase to boot, why not?!

You make the decision.

IMO, too many people trying to reinvent the wheel, when there are quality options out there. In addition, many of these people don't have the knowledge to know how to make a hybrid setup work properly, as they never built a motor before and don't know what to measure, look for, etc. You have to know what you're doing and what to look for or it can be an expensive mistake.

[SOHCinWA]

or you can just run with some k20 oem pistons.

its not cutting corners, it's called being on a budget. plus you dont need a forged piston for 200hp.

When it comes to reliability IMO , it is called cutting corners. I am all about being reliable and longevity. I have built "Budget" setups myself. Why? Because they were less expensive than doing it the right way the first time. Sure its great. But what most of us dont realize. After having to build the "Budget Build" 2 or 3 times over. Its no longer a Budget. It ends up costing more than doing it the right way with the higher quality parts.

Sure the parts may not cost as much. But having to go take your engine to get machined every time it needs a rebuild , and another set of gaskets, etc. It gets expensive.

When it comes to N/A builds. Especially with a DD. Yu want to get everything out of the engine you can. Weather its on the street or at the track. When you get beat by a bumper. You will have wished you had gone with the right parts in the first place.

[wed3k]

thats not cutting corners, that's just not knowing how to build it.

[sickocb7]

ok so i have been doing a lot of research the last couple days and this is what i found out:

the k20a2 pistons will work. they have the same compression height, same wrist pin height. they just need to be rotated 180 degrees.

the k20a2 pistons with f23 block, crank, rods, and f22a1 head will yeild a static compression ratio of 12.36:1

i feel with that setup and a built head you should see some really great results

[HondaFan81]

ok so i have been doing a lot of research the last couple days and this is what i found out:

the k20a2 pistons will work. they have the same compression height, same wrist pin height. they just need to be rotated 180 degrees.

the k20a2 pistons with f23 block, crank, rods, and f22a1 head will yeild a static compression ratio of 12.36:1

i feel with that setup and a built head you should see some really great results

Rotating pistons 180 deg...did you make sure your valve reliefs will work for the F22ax head assembly you plan to use? Did you do the appropriate measurements or research?

Have you even done a comparison using Bisimoto necessary parts to these hybrid parts, what is the price difference?

Also, have you planned for the type of camshaft you plan to use in the future and appropriate piston-to-valve clearances? How much will the pistons be in/out of the block?

[flcb7]

or you can just run with some k20 oem pistons.

its not cutting corners, it's called being on a budget. plus you dont need a forged piston for 200hp.

correct me of Im wrong but dont the k series pistons ware down the cyl walls faster b/c the pistons has to be flipped in to work with f series blocks???

[jdm92_accorn]

look man, imo the bisi setup is the best, its what im doing. i got the rods and the pistons for less than 1000 shipped. the machine shop shouldnt charge much more than 500-600 to bore the block and thats if they're high. a top and bottom gasket set from tas auto is around 300 for every gasket, the rod and main bearings from honda should be around 120 maybe a lil more but not much. then a new timing belt kit from tas auto is about 140 for the timing belt, balanceshaft belt(trash it), p/s belt, alt/ AC belt, new waterpump and the tensioner seperate. it could be build for around 2500-3500.

[sickocb7]

Rotating pistons 180 deg...did you make sure your valve reliefs will work for the F22ax head assembly you plan to use? Did you do the appropriate measurements or research?

Have you even done a comparison using Bisimoto necessary parts to these hybrid parts, what is the price difference?

Also, have you planned for the type of camshaft you plan to use in the future and appropriate piston-to-valve clearances? How much will the pistons be in/out of the block?

i will have the have the vavle reliefs cut as the exhaust reliefs will now be the intake reliefs......i can pick up a f23 block with pistons and rods for $100, the k20a2 pistons will cost about $50-$100. i have not checked with my machine shop on the amount it will cost but it wont be more than $700 for everthing

the piston-to-deck height is right at 0.000 using my calculator with f23 crank/rods, f22a1 head, and k20a2 pistons using a OEM .026 headgasket

as for the cam, im thinking of using the bisi stg 2......my setup will be clayed for proper piston to valve clearence

if my calculations are correct i should have no more than $1200-$1600 in the entire build........which with setup runing 12.36:1 or so compression, should yeild me 180-190 wheel hp