THEhomelessONE

Just bored thinking I might eventually get an H sleeved with some custom pistons instead of a big nitrous setup. I have access to pump e85 and hondata can play nice with flex fuel sensors. I know there's not much space in the chambers especially once some aggressive cams are in. Folks are running 93 pump with over 13:1 compression on mildly aggressive cams. I think 16:1 is approaching the limit of pump e85 from what I picked up browsing on other forums, mostly v8 stuff.

THEhomelessONE

Bump, I'd really rather go full time e85/sleeved/high compression vs nitrous.

TheShodan

iTrader: (14)

You are not likely to get much feedback on this area. Even the V8 guys only go up tlo 14.0:1 on VP fuels of C16 & Q16 field.

there's more to power than just compression increase.. bit you won't find much of a discussion here. Your best bet is to try it for yourself and be a pioneer for this endeavor if you want to get more information

THEhomelessONE

Thanks, yeah only site I was able to dig up anything substantial was unlawful, yellowbullet and all the big block v8 1/8 mi racing sites. I know DCR is what I should focus on but haven't found much info yet on what the limits of NA e85 are. I think epa did some tests up to 22:1 in tdi engines and some racers claimed to have gone up to 18:1 but I'm sure the massive cam(s) they run bleed off a ton of cyl pressure. I keep reading the usual "no more than 14:1 on e85" but that sounds too conservative when guys are regularly running 12:1 with over 30lbs of boost.

I'll ask some piston makers what they can get compression up to with the h22. Personally I think 15:1 would be totally safe, 16:1 with stage 2/3 cams and 17+ with some ddtech reapers. Lol just trying to find an easier way to 325whp NA.

lxrd_vtec

I'm just curious as to why a 14-16:1 compression for a H22? As an N/A guy, I feel like this is at the point where you might as well go turbo and save yourself the hassle. Or, go K. If I recall correctly, 4Piston's K27 was a 15:1 static CR and was pushing over 400 hp all motor, but was running alcohol (it's been awhile since I've read the article but I believe it was on super street if you want to look it up).

AllMtrRex

No need for anything but a stock bottom end 99% of the time. Tons of guys are going low 11's and high 10s. If you want to run methanol (Which is way cheaper than building a super high compression 10K short block) Mid to low 10's have been done, with stock K, F, H and J series. Some even with stock heads. If you are not concerned with ET's and are only after the numbers for some odd reason, that can still be achieved with stock bottom end. Mid 300 whp with the right fuel. Pop one, and buy another. Although, you shouldn't be blowing these up regularly.

If you are after 325whp, I'm sure you will be happy with 300whp while saving a few thousand dollars. H23 blue top long block. Used CNC ported head from reputable source. Used set of Skunk 2 Pro 1 cams. New valvetrain (Do not risk your engine on used valvetrain) to support the cams. A large plenum intake (Skunk2 ultra). A fuel system that will support Methanol (M1/M5). Rev the engine until it quits making power no matter what the internet tells you. 280-300whp!

Chance EG

I do not believe there is any Honda 4 cyl capable of making mid 300 with a stock block even with race fuel. Low 300s on an 11:1 stock K24 with a built head, maybe.

Bear in mind OP that if you go uber high with the compression and a really aggressive dome design on the pistons, it will likely impact what you're able to run as far as cam overlap and timing. There's a reason why people tend to stop pushing CR past a certain point, you reach diminishing returns and eventually it even does more harm than good, as far as practical applications.

AllMtrRex

This shop has a couple cars making right at 300whp....stock short blocks.

Jaywest ending up making 290-300whp on stock H22 short block back in 2015-16

Maxh2b went 10's with 280-300whp...stock f20B short block end and stock cams

K24's Stock short blocks have been making over 300whp and running mid to low 10's for 3-4 years now. Too many to list.

Several guys using nitro/m5 mixture and making ridiculous power. 300+whp....

But none of these guys will post on HT about which cams to use in their GSR/p30 piston build. They actually build all motor 4 cylinder drag cars.

AllMtrRex

11:1 can easily be achieved with 90% of all H/B/K/J/F/D stock bottom ends.

Chance EG

That wasn't the point I was trying to make, just stating what I thought the limitations of a stock bottom end/piston to be.

THEhomelessONE

Thanks for all the great info guys. I was set on 14-16:1 because it would run on e85 only and I'd like to get the most out of it. I know the h23v has a sweet crank compared to the other H's. Lighter, better balanced and stronger rods. But I'd fail inspection with an h23v so I'd have to swap internals over. They go for about $700 locally, not bad. Add some type s pistons (I don't think they just bolt up though and p2v would be a bigger issue?) and it's right at 1k. Or stick with the h22a1 crank, type s pistons and scat h rods for under $600, $200 for balancing and $200 for arp rod/main studs. Yeah I'm not afraid to spin it with decent valvetrain, actually plan on 9k with 5.13 fd. B18c5 has same RS ratio and we'd beat it to 9200, rod bearings maybe every year or two but that's it. Had a race shop tell me they've spun stock h23v short blocks to 10 or 11k in their drag cars lol.

I don't get how they're getting 280+whp with only around 11.1-11.5:1 compression though. Going to try and find some dyno graphs but pretty sure pro 1's drop off by 8.5k and I keep reading pro 2's want over 12.1. Interesting stuff thanks AllMtrRex.

mattfreezy

with enough money you can do anything