Re: USDM Timing Belt for B20a
Quote:
Originally Posted by
carotman
Very interesting post. I don't know if 26.4mm would work. I measured 3 OEM Honda Timing belts I have here and they all are 23mm wide.
The aftermarket belts we are using, 25.4 mm (1.0") wide work good and I do not see 26.4 being a problem. Having a high quality race bred belt would be a welcome addition to the B20a arsenal of hi perf parts I am sure.
I have not laid hands on the Motorcraft version of the belt, but I am sure it would be superior quality as well considering it is an oem part.
thanks for posting Espirit2, it is always interesting and exciting to see other car entheusists (especially a high end car like Lotus) share in knowledge and community here with us at 3geez.
Re: USDM Timing Belt for B20a
Well, I would buy one of those belts for sure! We just have to check if the width will work.
Re: USDM Timing Belt for B20a
I just talked with Jeff at JAE about their HNBR belt's width.
(805) 967-5767
It turns out that Gates made the HNBR belts using the tooling set-up that makes the T188 HCR and T249 HSN belts, so they're the same 25.4 mm width... not the Lotus 26.4 mm width. If you're already using those Gates T188/T249 belts with no fit issues, then the JAE/Gates HNBR belt should fit as well.
Belt life is a function of lots of engine-specific factors, in addition to the belt design. It's unrealistic to expect Gates or any belt manufacturer to make a mileage claim for any engine without lots of testing (normally done by the engine manufacturer), and that's just not happening for old engines. But in generic terms...
HCR belts (Gates T188) were roughly 50,000 mile belts.
HSN belts (Gates T249) were roughly 100,000 mile belts.
HNBR belts are the next step toward 150,000 belts.
In any case, any given engine's belt service interval might be more or less than that based upon testing and how aggressive management wants to be.
In the USA, there are govenment mandated durability standards, including for timing belt life. That's what drove the introduction of the HSN ~100k mile belt, and now the target has been moved out to 150,000 miles.
HNBR belts are the next step toward that goal. I don't know if they've fully achieved that goal, but they're going in that direction and are currently the best timing belt technology on the market. HNBR isn't a Gates exclusive, but Gates Racing and JAE are the only ones making an HNBR belt in the 188/249 size we can use. If we want one, it's our only option.
I wouldn't suggest that you slap an HNBR belt on your B20A and leave it there for 150k miles, or even much longer than the original Honda spec... that's your decision. But it is a stronger, more durable belt. If you drive the car hard, track it, or otherwise spend lots of time bouncing off the rev limiter, the new belt could be a good insurance policy even if you don't stretch the service interval.
That's the way the Lotus crowd is approaching it. Our engines are not clearance designs. If the belt goes, the valves & pistons collide, and things get very expensive in a hurry. Anything that reduces that risk is seen as a good thing.
Tim