<newbie post alert> Are SCCA IT honda's running their JDM counterpart motors? In short, I need a new motor for my tired Integra running a B18B1 motor. Its JDM counterpart is a B18B. The B18B is the same motor except for its slightly higher compression (9.2.1 vs 9.4.1). I'de hate to get a B18B motor just to find out that it can never run in ITA. The GCR reads as though this is OK to do for ITA.
Running a JDM motor in IT Honda
- Thread starter CPeirce
- Start date
Welcome!
IT rules require that you run US-spec parts only. For example, Canadian VW Golf III's (the make/model I race) were available with manual steering racks. No US model was, so we all run PS. Go download the SCCA GCR (our rule book) and get familiar with the specifics before you spend any $$. You were right to check!
K
IT rules require that you run US-spec parts only. For example, Canadian VW Golf III's (the make/model I race) were available with manual steering racks. No US model was, so we all run PS. Go download the SCCA GCR (our rule book) and get familiar with the specifics before you spend any $$. You were right to check!
K
mossaidis
New member
Welcome SIR!
Questions? Why does the B18B have higher compression? Different pistons? Are the TB/IM setup the same as well? what about port size?
Kirk is correct. USDM only per the rules. Why? 1) Though you are allowed to change pistons in IT, they must be similar configuration, dome, dish, etc. 2) There are undocumented variances between USDM and JDM which make it very hard for tech and others to determine if you are legal at min to the "sprint" of the rules.
My advice if you are truly set on using a JDM engine, take the trouble to make sure you have USDM pistons and your region is "ok" with your setup. Make sure your competitiors are aware of your adjustsments. BUT do not complain when/if someone protests you for having B18B stamped on your block and not B18B1 eventhough you have "made" a "USDM" IT legal-ish motor... cause you have not.
I was in the same boat as you. I could have purchased a D16A SOHC ZC JDM motor which is EXACTLY like a D16Z6 USDM motor and I could prove the were the same... (IM, pistons, head all had the same part numbers). Still, someone could protest me and legally win.
Look it into getting your old B18B1 motor refreshed.
Mickey
Questions? Why does the B18B have higher compression? Different pistons? Are the TB/IM setup the same as well? what about port size?
Kirk is correct. USDM only per the rules. Why? 1) Though you are allowed to change pistons in IT, they must be similar configuration, dome, dish, etc. 2) There are undocumented variances between USDM and JDM which make it very hard for tech and others to determine if you are legal at min to the "sprint" of the rules.
My advice if you are truly set on using a JDM engine, take the trouble to make sure you have USDM pistons and your region is "ok" with your setup. Make sure your competitiors are aware of your adjustsments. BUT do not complain when/if someone protests you for having B18B stamped on your block and not B18B1 eventhough you have "made" a "USDM" IT legal-ish motor... cause you have not.
I was in the same boat as you. I could have purchased a D16A SOHC ZC JDM motor which is EXACTLY like a D16Z6 USDM motor and I could prove the were the same... (IM, pistons, head all had the same part numbers). Still, someone could protest me and legally win.
Look it into getting your old B18B1 motor refreshed.
Mickey
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mikelawson
New member
very nice suggestion Many Thanks 
this. parts availability for the B18B1 is very good, and you can get oversized pistons directly from honda if you need them. If you aren't comfortable doing the work I promise there is someone near you who is.
Andy Bettencourt
Super Moderator
Just so we can help you here too, what rule(s) are you citing?
even if everything else is the same, the block lacks the "1" in the desingation stamp (about an inch under the head, bell housing side, flat area facing you) so it'd be hard to defend it in an ARRC win type scenario.
regionals? run it if you have no other viable option.
I disagree, Chip. Given the "equivalent parts" rule in IT (and ST, too) then if the part is functionally the same, then it's legal. I don't think the intent of the rule is to require the parts be absolute copies; after all, if it did, then things like logos and stamping which are copyrighted by the OEM could not be placed on otherwise-legal aftermarket parts. - GA
I was under the impression that head and block castings were to be OEM. I guess I never thought about it as the rule makes no distinction. interesting.
still asking for a can of worms in some cases, but by Greg's reading it should be OK -ASSUMING EVERYTHING IS IDENTICAL- which I belive, but cannto prove it is in this case.
still asking for a can of worms in some cases, but by Greg's reading it should be OK -ASSUMING EVERYTHING IS IDENTICAL- which I belive, but cannto prove it is in this case.