So next year I'd like to run H1 Honda Challenge (road racing) with my car (it's currently an H2 car with a 180 whp B16A2). Here are the rules:

• Any OEM B18 block/crank/rods (LS, GSR, ITR) - cannot sleeve the block
• Any OEM head (B16A2, GSR, ITR), does not have to match block/crank/rods
• Any compression ratio, can deck head/block
• Any cams, valve springs, retainers, and valve job, but must use OEM valves
• Any intake/exhaust
• Any head porting "from the block up", must use untouched OEM ITR IM & TB
• Must use OEM Acura/Honda pistons (PCT, P73, P30, etc), but do not have to match block/head, can bore out block
• Any gas/E85 can be used
• Will use S300 and lots of dyno tuning

Off the top of my head, I see an ITR block, ported B16A2 head, Toda C cams, and P30 pistons being a safe pick, but I thought a GSR block yielded a higher CR, may be worth looking into. Thoughts?

The K-series and B20 VTEC guys are almost all 240-260 whp, I'd be coming in at a lower weight, but I'd like to see 230 whp or more.

 

itr/gsr block are the same.

 

I used to run H1, it's going to be real hard to make 230whp+ out of 1.8l engine.

Also the rule stated that you cannot port the head more than an inch from the head flanges, meaning from the opening of the port, you cannot port more than an inch inward, intake and exh ports. Which really mean port matching only. I'd use a stock unmolested type R head and port match it. That would still complies by the rule since the pockets are ported from factory. I can see 210-220whp, 230 is a stretch.

 

b18c block align honed, bored out .020" over.
b18c crank balanced and polished.
b18c rods, upgraded arp rod bolts, resized rods, balanced.
b16b pistons with total seal rings.
acl race bearing, I ran acl x bearing for the rods (0.001" looser).
arp head studs.
b18c5 port matched cyl head.
supertech springs/rets.
ported matched b18c5 intake mani/throttle body.
S2stg2 cams
I made my own header/exh.
the car made 218whp/145ftlbs

that was my old setup

 

-Stock ITR longblock (or B16A head if you already have one, they're basically the same). EDIT: after reading the above post regarding the rules a Type-R head would be best.
-RLZ (or similar) portwork, and millig (or welding) to get the CR as high as possible and a good squish area.
-"ported" 82mm pistons (stock usdm type-r, or jdm type-r if they are possible to get), and the valve pockets will probably have to to be enlarged (because of the headwork/milling).
-Thinner head gasket.
-E85, big bosch injectors.
-Custom kinsler ITB. Custom header (SSR? DTR? hytec?)
-AEM EMS with COP.
-Pro2s, or maybe M24X? Or bigger (pro3, or M25).
-Maybe low friction coating?

 

Those are the old rules from maybe 2007 or prior, B-series can port the heads in H1

 

Responses:

• Since we can port the head, does that change your pick?
• Yes, JDM ITR pistons are obtainable in this timeframe, but only up to 81.25mm
• RLZ valve job and port work...how did you know
• Got Injector Dynamics injectors already
• COP, good point, hopefully Hondata will finish theirs, then I can keep my S300
• Custom header...I have my sights on an SMSP B20 VTEC header that's for sale
• Interesting you don't mention the Toda C's. Are the Pro2's and M24X's clearly better?
• Can't do friction coating beyond what the OEm part comes with

 

Ok, well, if that's the case it does not matter if you use the b16a head or the b18c-r head.

If the high CR JDM pistons only come in 81.25, what about buying a JDM B18C-R longblock, and not replacing the pistons? (save money on pistons and cylinder boring).

I guess it's either that or using USDM 82mm P73 pistons (more displacement butt less CR).

I you already have Hondata S300 it definitely should do the job. COP is probably not the first thing you should spend money on either (AEM and COP was more like if money was not an object :p).

I don't have first hand experience with Toda cams, but other people in here do, so just wait for response. Choosing cams is always hard.

 

I agree with most of what huey, crx=si, posted but I disagree with the rings.

Here is what I would amend or add below:
Bearing clearances should 0.0018 for the rods and 0.0018 for the mains except the middle which should be 0.002".
I would run PTW clearance at 0.002".
I would run standard hasting rings at 0.019" top and 0.022" not total seal.

 

this is also really good , to each and their own. I used loose rod bearings to get more oil between the bearings and journals, although sacrificed a little bit of oil pressure. I shimmed my relieve spring in the oil pump to gain back the pressure though. Cooling system also really important. Here in texas, we see 107 deg outside today and that take a toll on the cooling system. I end up used a griffin mustang 5.0 radiator with a custom built header tank for it, worked great, never see temp go pass 185 deg in 100 deg heat beating it up.

 

Just curious but is a 82mm LSV out of the question? I would feel much better about raising compression ratio with a longer stroke rather than throwing a HUGE domed piston under the head. You can run flatter domes, creating more clearance for larger cams and still accomplish about the same compression. Not to mention you would have a little bit more grunt with the 89mm stroke coming out of the corners. Also use a GSR ported head for more compression if you would like... If i were to build one this is a rough list:

82mm B18B block, crank and rods w/ PR3 pistons and GSR head (12.5:1) Assuming you used a OEM HG and the head and block were virgin.
Skunk2 Pro2 cams and valve train
3" pipe w/ BPi stack
Your custom header selection
ITR/B16 tranny with LSD...possibly shorter FD?

If you ran P30's in this setup your looking at 12.65:1 and JDM ITR's 12.7:1. Swap out for a B16 or ITR head and lose roughly .3 compression points.

Im sure Im missing something but that would be my approach...slightly more displacement will yeild slightly more power.

 

What about a B20 block, .020" overbore OEM pistons (valve reliefs flycut)??

Is that allowed? Or do they have to be stock unmodified pistons?

wait, nevermind. Just saw it has to be a stock b18 block...

 

LS-VTEC is certainly legal! Is it possible to get OEM Honda 82mm pistons? And will the block put up with being bored say 0.050" without needing being sleeved?

We can deck the head/block to get whatever C/R we want (any suggestions?), so I think I'd do a B16 head (supposedly flow better than a GSR, right?). Already got the AEM 3" intake with BPi velocity stack, ITR trans with FD & clutch diff, and got my sights on a big tube SMSP header

Yeah, B20 is another 100 lb of weight penalty, and the blocks crack because the walls are so thin, and we can't sleeve them. And yes, pistons have to be OEM Acura/Honda

 

I'd run 81.5mm P30's in an LSV then and never look back. 2 layer HG w/ a B16 head approx: 12.5:1 and GSR head 12.78:1. Just my opinion but the added displacement can always be used, especially when were talking acceleration out of corners.

 

I wouldn't road race a ls/vtec...arp's or not. Spinning up to 8-9k a couple times down a drag strip or on an auto x course is a whole different ball game then 20 min sessions @ a consistant 6-9k, but that's just my opinion, I could be wrong

 

Are you allowed a dry sump, or at the minimum, a vacuum pump?

 

Its no different than those who road race B20V's. Same crank, same rods.

 

No dry sumps, but I do have an Accusump in the car already. LS/VTEC is definitely a gamble in the oil starvation department, our races are 25-45 mins depending on the event

 

I was thinking more along the lines of using ultra low tension rings and using the vacuum pump to keep the rings sealed. That's usually worth a lot of power.

 

Type r oil pump and water pump and you are set to roll. Maybe even alter the shim in the oil pump to raise Oil Pressure some.

 

Yea I know. Not sure if it's legal but what I would build is a b20 block with itr crank and rods, just a little piece of mind and it would last longer so you could spend more $$$ on tires and gas

 

obd2 oil pumps are all the same and the water pump is same as b16/gsr. But yea, good idea to get new ones.

 

Since gas is unlimited I would run as high CR as possible as long as you can afford the gas for it.
Have you checked what this years winners are running?

 

Never understood why people always say to get a type r oil pump

 

I think your HP goals are off but I would just pick up a JDM ITR motor and trans, good bolt ons and cams, and then... wait for it... not sure on the rules but GEARING! Short gearing does wonders for small displacement low torque motors, gearing is a torque multiplier. The type R motors were built to withstand some serious abuse. There are little details that make it more suitable for endurance compared to every other motor.