Ok, the oil rings in my ITR are shot at 90,000mi and I want to replace the pistons with Civic Type R ones. At the same time, it is also time for a new transmission, so I am a bit limited on funds. My question is, if I install the new pistons and replace all the lower end bearings, which would bump my compression up to around 11.8:1, is it mandatory to install bigger cams? I plan on replacing the valves, springs, and retainers with Skunk2 parts, and putting in new valve seals, so the upgrade in cams wouldn't be as difficult in about 3 months, but would I kill my engine running this setup? Its just driving me nuts the amount of oil my car is burning, and I would like to get the problem fixed right away. Would getting a Hondata and bigger injectors before the pistons solve the problem?

Thanks,

Matt

 

limited on funds.. but replacing parts where there is no need to replace? maybe I'm just confused..

and why replace the valvetrain when you are not installing bigger bumpsticks? there is no reason to unless there's a problem.

 

You can run ctr's w/out getting bigger cams, but the compression will be about 12.5:1 at all times since there will be no overlap on the stock cams (i.e. static and dynamic compression will be the same). That will ikely require something other than the stock ecu, i.e. hondata. If you plan on getting bigger cams in the future they are a good call, but don't forget all the other things that you need w/ big cams: injectors, engine management, valve springs, possibly timing belt, etc. If you want a compromise, get Civic Si pistons. They will raise compression enough that you could take advantage of mild cams later, and you won't have to worry about the stress of the extremely high compression ctr's will give you.

 

I am replacing the valvetrain, because I will be installing bigger cams, just not for 3-4 months. I dont want to have to pull the head a second time, so I am doing all the mandatory work now.

Thanks,

Matt

 

If you really want to do it right, get ctr or si pistons that are .25 over, get the block bored and honed, then go from there. Also, you will have new rod and main bearings. Rods and crank should be fine. That should solve your oil burning problems. BTW, where are you getting this done? I live in NOVA now and noticed you are in Alexandria. Good luck.

 

I am contemplating doing it myself, but I usually go to Inline Pro.

Matt

 

Please explain static and dynamic compression. I thought NA vehicles always had static compression. Enlighten me.

 

1. Your CR will be OVER 12. around 12.2-12.5:1
2. You need to pull the block and have it honed before installing new pistons
3. Smaller cams means dynamic CR is higher, which increases the chances for detonation.
4. hondata and injectors wont help the rings seal
5. Static CR is just the ratio of volume at TDC to volume at BDC. Dynamic takes into account otherfactors, such as cams.

 

When I said Hondata and injectors, I meant before I installed the new pistons and rings, not as a remedy for ruined piston rings. Can't I hone the cylinders with a ball hone while the block is still in the car? Honing is just putting light cross-hatch marks in the cylinders, not boring them over .25mm which would require removal, right?

Thanks,

Matt

 

Thats right, but i wouldnt do it in the car. I only hone my blocks with a honing
machine. If you want to try it, go ahead, but be prepared to pull the motor out
afterwards anyway to replace the rings again and rehone.

 

only 90K miles and your rings are blown out .......? that pore car musta been beat to hell getting to 90K