December 2013 Fastrack

[mossaidis]

Just guessing here, I would imagine that many HC cars in H1 and H2 have JDM swaps.

[Greg Amy]

Just guessing here, I would imagine that many HC cars in H1 and H2 have JDM swaps.

Likely. However the component parts are typically the same as USDM engines expect for cams and pistons. If that were the case, and assuming the cams are within STL specs, I contend the engines are compliant to the regs due to the "aftermarket source" reg and specific JDM approval is not required.

I've gotten into spirited debates with folks over this interpretation. Many contend that since the engine has "B16A" (or whatever JDM designation) stamped on it, that automatically makes it non-compliant. I disagree. The reg states something like parts must be "the exact equivalent of the original parts". However if we can obtain parts from, say, NAPA and use those, are you going to argue that the NAPA parts are not compliant because they may have different part numbers cast into, or stamped on, them? In my mind, if the parts are dimensionally and metallurgical the same between the USDM and JDM engines, and no component exceeds either OE or STL-allowed specs, then it's compliant to the STCS.

If having that "B16A" stamped on the block bothers your competition, then just grind it off.

- GA, inviting people to read his signature at the bottom...

[Andy Bettencourt]

Aren't JDM engines specifically disallowed except for specific line-item inclusion?

While I understand your position, and tend to agree with the fact that the resultant unit would be compliant, it would seem that starting with a non-USDM core is not allowed specifically by the rules and any 'core' without proof of USDM origin would be technically illegal.

Maybe a rules re-write is in order?

[tom91ita]

I guess I am thinking more along the lines that if the "A" of B16A bothers the competition then that is a reason to add one to the "B16"

[Greg Amy]

Maybe a rules re-write is in order?

Nope. Alternate parts are allowed per the regs, as long as they're the same part (dimensions and materials). As long as the specs are the same, the parts are allowed.

If you disassemble both a USDM and a JDM engine, spread the parts all across the tech shed floor and compare them, and find that they're all exactly the same part, yet the only difference is one is stamped "A" and one is stamped "B", then - as per Roffe Corollary - "if it says you can, then you bloody well can!" And if you counter that the stamps and casting marks and ink spots and everything else has to match on allowed replacement parts, then I'd counter the regulation is completely pointless, because were a supplier to attempt to sell parts with all the same casting marks and stamps and ink spots they'd get sued by the OE manufacturer.

The reg is clear: the parts must meet "dimensional and material specifications of new parts from the manufacturer".

These do. They're compliant.

And, before this board gets all high and mighty about it, maybe it should look inward to find out where that reg came from...and where else its interpretations may apply...?

- GA

P.S. Here's the reg:

Replacement parts may be obtained from sources other than the manufacturer provided they are the exact equivalent of the original parts. The intent of this rule is to allow the competitor to obtain replacement parts from standard industry outlets, e.g., auto-parts distributors, rather than from the manufacturer. It is not intended to allow parts that do not meet all dimensional and material specifications of new parts from the manufacturer, unless otherwise allowed in the Super Touring category or class rules.

"Same old axe. Replaced the handle twice and the head once, but it's still the same ole axe."

[mossaidis]

... having flashbacks... of prior... threads on UDSM vs non-USDM...

https://improvedtouring.com...ht=USDM&page=3

https://improvedtouring.com...&highlight=JDM

https://improvedtouring.com...&highlight=JDM

https://improvedtouring.com...highlight=USDM

... enjoy this long, boring, non-racing (a few exceptions) weekend.

[Greg Amy]

... enjoy this long, boring, non-racing (a few exceptions) weekend.

Give me the Cliff's Notes version...I'm busy drinking beer.

It's always been my contention that extra-US-market engine are compliant as basis for IT/ST builds as long as the components used are exactly the same as the US-spec car. This goes back to the early 2000s when someone (honestly, not me or "a friend") wanted to use a JDM SR20DE as a basis to build an ITA engine. In my opinion, it was legal to use a JDM SR20DE to build an ITA engine, as long as everything that ended up in the final assembly was the same - dimensionally and metallurgically - as the US SR20DE.

Same applies to STL. If someone wants to run, for example, a B16A (versus a US-spec B16A2) in STL in their Civic, I say it's compliant as long as the compression ratio is below 11:1 and the total valve lift is within .425" (dunno if it is). I know the B16A has different pistons and cams, but the compression ratio is within 11:1. And pistons and rods (and cams) are free (within prep limits.)

Now, if someone installs a JDM B16A engine with some wild-ass intake manifold and throttle body that was never installed in the US and tosses that into the car? Not compliant. Parts are decisively not what was installed in a US-spec car.

Otherwise, in the end, it really is the same thing, except for what the Shinto eunich ex-Ninja monk stamps on the block as it passed by on the production line. Compliant to the alternate parts letter, and compliant to the alternate parts spirit.

- GA

[Z3_GoCar]

Give me the Cliff's Notes version...I'm busy drinking beer.

It's always been my contention that extra-US-market engine are compliant as basis for IT/ST builds as long as the components used are exactly the same as the US-spec car. This goes back to the early 2000s when someone (honestly, not me or "a friend") wanted to use a JDM SR20DE as a basis to build an ITA engine. In my opinion, it was legal to use a JDM SR20DE to build an ITA engine, as long as everything that ended up in the final assembly was the same - dimensionally and metallurgically - as the US SR20DE.

Same applies to STL. If someone wants to run, for example, a B16A (versus a US-spec B16A2) in STL in their Civic, I say it's compliant as long as the compression ratio is below 11:1 and the total valve lift is within .425" (dunno if it is). I know the B16A has different pistons and cams, but the compression ratio is within 11:1. And pistons and rods (and cams) are free (within prep limits.)

Now, if someone installs a JDM B16A engine with some wild-ass intake manifold and throttle body that was never installed in the US and tosses that into the car? Not compliant. Parts are decisively not what was installed in a US-spec car.

Otherwise, in the end, it really is the same thing, except for what the Shinto eunich ex-Ninja monk stamps on the block as it passed by on the production line. Compliant to the alternate parts letter, and compliant to the alternate parts spirit.

- GA

And there you have the rub, because:

e. It is permitted to use the OEM intake and throttle body from either the chassis or the installed engine.
1. Regardless of the intake chosen, the total number of throttle bodies must remain the same as the installed engine.

and:

2. All cars shall use the installed engine’s stock air throttling device (e.g., throttle body, carburetor) and intake manifold, unless noted otherwise.

If you install the JDM motor then you have to install the JDM ITB manifold, which as you point out isn't allowed as the JDM is a non-USDM item.