my dad and i are building my crx hf for track and auto x use for nasa events. i read the honda challenge rules back and forth about 3 times now and i dont see anything that says i cant run vtec head on a a6 block. so my question to ht is would i be able to run h4 with this setup

 

No. The VTEC head was never stock for a CRX, or any EF chassis, therefore it would be illegal.

You should note that the EG & EKs that DID come with that head are classed at a higher minimum weight in H4.

You could run it in H2 at 2000lbs with the following allowed:
• Cam is unrestricted
• Compression via head gasket and head shave is unrestricted
• Intake Manifold is unrestricted (with the exception of Individual Throttle Bodies)

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by thawley &raquo;</TD></TR><TR><TD CLASS="quote"> .

You could run it in H2 at 2000lbs with the following allowed:
• Cam is unrestricted
• Compression via head gasket and head shave is unrestricted
• Intake Manifold is unrestricted (with the exception of Individual Throttle Bodies)</TD></TR></TABLE>

you sure the mini-me is legal in H2? I am not sure but think it isn't legal....

10.3 H2 Limited Preparation Vehicle Engine Preparation

1) A USDM
D16A6 may not use pistons from a D16ZC engine and a head from a D16Y8

 

I think that rule more pertains to swapping pistons from a different block... BUT since the B20vtec is not allowed in H2 I would assume that Mini-me swaps are also not allowed

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by unrealwrc &raquo;</TD></TR><TR><TD CLASS="quote">I think that rule more pertains to swapping pistons from a different block... BUT since the B20vtec is not allowed in H2 I would assume that Mini-me swaps are also not allowed </TD></TR></TABLE>

how to you figure it only applies to pistons... It says "d16a6 block..... d16y8 head."

 

a6 block with zc pistons.


But what you should have copied is 10.3.a

a) The entire engine assembly, (cylinder head and block) MUST be constructed entirely of Honda/Acura
OEM parts. Cylinder head and internal engine parts must be OEM parts for that particular engine code.

 

but it also only states ...

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by slammed_93_hatch &raquo;</TD></TR><TR><TD CLASS="quote">

10.3 H2 Limited Preparation Vehicle Engine Preparation

1) A USDM
D16A6 may not use pistons from a D16ZC engine and a head from a D16Y8 </TD></TR></TABLE>

so what if you chose 1 or the other. zc pistons OR y8 head with the a6 block. thats why you copy a more descriptive part in the rules

 

I guess I just meant single-cam VTECs. Seems like there's no shortage of them in the bone yards. If it takes a complete long block to be legal, so be it.

Is there an advantage to doing a mini-me head swap over just getting a complete single-cam VTEC engine?

Thawley – who knows nothing about this single-cam world of which you speak

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by unrealwrc &raquo;</TD></TR><TR><TD CLASS="quote">a6 block with zc pistons.</TD></TR></TABLE>

Not legal according to what I read in the rules:

7.1.c

"c) Factory replacement pistons or the exact equivalent shall be used. Exact equivalent shall be defined as the same dome/dish/valve relief configuration, weight, ring thickness and location, and pin location as the OEM replacement piston."

Anything other then the factory pistons, their exact equivalent, or the overbore pistons are illegal in H1-5 unless class specific rules state otherwise, H4 does not have separate rules outside of the main rules.

They are not legal in H2, H3, H4, or H5, the only class that the hybrid engine would be allowed in is H1.

Here is the specific rule for H2:

10.3.a

"a) The entire engine assembly, (cylinder head and block) MUST be constructed entirely of Honda/Acura OEM parts. Cylinder head and internal engine parts must be OEM parts for that particular engine code. Updating and backdating of parts for that engine code is permitted. No aftermarket parts are permitted in, the “bottom end,” of a Limited Prep Vehicle engine (except were specifically stated). Example(s): 1) A USDM D16A6 may not use pistons from a D16ZC engine and a head from a D16Y8. 2) A USDM B18C1 may not use ITR crank and pistons with ITR head and call it a B18C5. 3) A JDM B18C (GSR) may use ITR crank, pistons and ITR head and call it a JDM ITR engine since that is the proper engine code for both engines."

 

no there is generally no advantage to a mini-me swap that cannot be achivied by sourcing the right vtec engine. only difference you can create becomes I-vtec, E-vtec and Vtec heads on different blocks. also many heads generate different compression rations on different d blocks. IE a z6 compression is like 9.6 and a y7 block is like 9.4 when y7block+z6head is used the compression drops to 9.1-9.2

 

This being said and rules clarified... How many people are actually competitive in H2 with a D engine?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by unrealwrc &raquo;</TD></TR><TR><TD CLASS="quote">but it also only states ...

so what if you chose 1 or the other. zc pistons OR y8 head with the a6 block. thats why you copy a more descriptive part in the rules </TD></TR></TABLE>

That is getting a little net picky, in the English department there.

Bottom line it isn't legal...

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by thawley &raquo;</TD></TR><TR><TD CLASS="quote">I guess I just meant single-cam VTECs. Seems like there's no shortage of them in the bone yards. If it takes a complete long block to be legal, so be it.

Is there an advantage to doing a mini-me head swap over just getting a complete single-cam VTEC engine?

Thawley – who knows nothing about this single-cam world of which you speak</TD></TR></TABLE>

I think that there can be advantages gained through compression, via different combustion chambers.

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by unrealwrc &raquo;</TD></TR><TR><TD CLASS="quote">This being said and rules clarified... How many people are actually competitive in H2 with a D engine?</TD></TR></TABLE>

I have won a few races in H2 with my H4 93 civic SI, but we really didn't have any real H2 cars.

This is H2s first year, so it will take time, but i don't think the D will be very popular.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by unrealwrc &raquo;</TD></TR><TR><TD CLASS="quote">This being said and rules clarified... How many people are actually competitive in H2 with a D engine?</TD></TR></TABLE>

In a Civic EG Chassis I had trouble making weight, I was ~200lbs overweight, and with me on a diet and a few more things removed from the car it could have gotten close to the weight limit.

Power wise, I don't really think that anyone has explored the posibilities, as the D16 can use a can, and any intake manifold outside of ITB's...so you never know how competitive the D16 really is outside of a build car, but it might just be a damn good car once someone has fully explored the rules.

 

Z6 and Y7 have the same chamber volume so CR is not changed. Attention to any possible OEM valvetrain parts swaps might be allowed could free up a couple hp.

 

Colin Botha, the 06 H4 champ is running H2 this year. I dont know if he has a d or a b though.

 

cool thanks for all the info guys .. so i guess i will just have to run a full a6 head and block to run h4

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by smokin rubber &raquo;</TD></TR><TR><TD CLASS="quote">Colin Botha, the 06 H4 champ is running H2 this year. I dont know if he has a d or a b though.</TD></TR></TABLE>
I'd bet a D. He's got a lot of parts for them...

 

yes he does from his super D in H1 experiments, but you cant combine parts like that in H2, plus he never had a lot of luck with reliability during those times.