I don't know if this is the right forum or not. If not, I apologize.


I am looking at building my car up a bit NA.
Roughly it will include intake, TB, port & polished head, oversized valves, high compression pistons, header exhaust, aem ems. Blah blah...

What I am wondering is the integrity and endurance of the bottom end.
If I raise the compression and beafen up the head, will the connecting rods or sleeves keep up?
I am hoping to rev to 9300rpm, and have the compression around 12:1. I am not sure who on the board has done this, otherwise I would have read up more.
But to rev to 9300rpm and raise the compression, would I need new connecting rods and/or sleeves?

And one more similar question:
I am getting custom pistons, and a redone top end. With that in mind, would new cams be "worth it"? I mean, internals dont show and I don't give 2 shits about bragging rights... But will I be able to squeeze out a few more HP AND remain drivable with Spec B or C cams? I will have the pistons and top end to match the cams, so I will only need a "new" tune, the Cams ($1100), and cam gears ($400). Will that $1500 yield decent power and keep keep my car reliable or daily drivable? Thanks.

 

What pistons are you getting? Sounds like you are planning to combine aftermarket pistons and stock sleeves.

 

its alot cheaper and easier to just go FI i know some guys just love NA power, but i would just reccomend going with an SC, you will see more hp for less $$.

 

The stock bottom end should be fine for your NA build up. Since you're replacing pistons might as well upgrade the rods and sleeve the block since the motor is torn down just in case you go FI some day.

You should be able to rev it to 10krpm with that setup.

 

The crank and block are virtually bullet proof. I ran stock cylinders (no sleeves) on my engine making ~340 hp (NA) without any problems. I personally have not used the stock connecting rods, but it appears that they will hold up quite well to 9300 rpm.

I don't know who is making your pistons, but you might try Larry Widmer at Endyn. He has Weisco pistons made with a specific dome shape that works quite well on the F20C engine.

12:1 CR will require a higher octane fuel (or additive) to prevent detonation.

 

Hrmmm...

Good feedback. Thanks a lot.

Okay, I will get some rods also. Most likely the Cunningham forged Titanium from Alaniz? Dayam money....

Is there something wrong with stock sleeves and new pistons?
Sleeves are so pricey, but if needed, I'll do it.

I know FI is more hp/$.... But... Oh well...

Also, what is the highest CR that can be done on 92 octane?

As for my pistons - they will be custom to my spec (which I don't what that is yet) made by Supertech.

Thanks again.

 

The stock sleeves are not iron and require a very high silicon content piston. Aftermarket pistons for the most part are not compatable with the factory cylinders so most go with new sleeves.

 

So if these new pistons had a high silicone content, I wouldn't need new sleeves?
Okay, seriously - no more trying to do it cheaply. Shit. Sleeves.
Where should I look? Only ones I know of are the Benson's from Alaniz.

 

You can find the right piston for stock sleeves. For the octane you are using (92), you are wasting your time raising compression a full point.

Alaniz does RS sleeves not Benson.

 

Asura - You're right, I just checked the website again and came back to correct my error. Not sure where I heard Benson from. Probably a signature in the FI section, haha.

I'll see if Supertech can make sleeves with the silicone content (hopefully they'll understand better than I do) compatible with stock sleeves.

Could you please explain why raised compression (be it 11.5:1 or 12:1) would be a waste of time on 92 octane? (Not questioning your knowledge, just trying to learn).

Thanks for the helpful input from everyone.