Cog/Gilmer Belt Drive for FD - Thoughts?
 

With regards to the problem of the water pump pulley slipping when eliminating the airpump, I know that there are idler kits out there to prevent this. But I was thinking that another solution might be to use a Cog/Gilmer belt drive system, similar to the one that Mazdatrix or tweakit.net offers for earlier RX-7's. Obviously, you need to get rid of P/S and A/C for this to work, but the main problem is that the waterpumps on FD's spin the opposite way. So, to get around this, what if you were to use a double-sided Gilmer belt, similar to the attached picture of a double-sided timinig belt? To me, that seems like it would provide enough grip to prevent the water pump pulley from ever slipping. What do you guys think?

greene brothers in NZ makes a kit for the fd. vest racing uses the kit on his car hes building. He has a thread on here you can see some pics.

heres a pic of the fd one off vest racings thread hope he dont mind if i use it.

Attachment 710628

Aha, thanks, didn't know anybody made one for the FD. The waterpump pulley in that kit is still smooth though. My idea was to have a cog type water pump pulley as well and use a double sided Gilmer belt, seems like it would eliminate the chance of slippage that way.

It would be tough to find a timing belt that small. Plus i dont believe that second gen WP pulley will fit our wp.

where can i purchase this? I've looked all over the interweb and I haven't found a thing. Also there isn't much on this forum about that piece for the FD.

thanks

betty

It's a custom built setup (i.e. not mass produced for sale).

Only problem is, this appears to STILL rely on the smooth backside of the belt to contact the water pump.

Would a longer belt and a gilmer style pulley on the water pump be possible?

Like it's been mentioned, the waterpump spins the opposite direction, so it'd have to be a double sided Gilmer belt

pacman....it sounds like there aren't many options on this proposed set up....unless you can find a custom fabricator/speed shop type business to do it.

You are correct, I must have forgotten that fact sometime between finishing reading the page and hitting the reply button.

Being that there are a few idler pulley solutions to combat belt slippage, what's the point?

I never saw problems with my old setup (greddy pullies) that I ran for approx 7 years but I couldnt deny that I disliked being able to move my water pump pully by hand when reaching in the bay.

I'm now running Dan Chadwick's (tweakit) idler pulley and the wp pulley definitely will not move no matter how hard I crank on it by hand.

Not the most scientific test, but it gives me better peace of mind.

My last engine was sold running and with good compression to someone who promptly did an extended burnout with zero fuel in the tank. As such, it's back at our shop and disassembled with massive detonation damage. I'll check the bearings for abnormal wear to see out of curiosity if the 7 years of use with the greddy pullies (and presumably over-tightened belt) caused any issues.

I saw some traffic about using the series 5 front housing. any thoughts?

I messaged the greene brothers racing yesterday to see what the deal is on the pulley kit.

I just like mods that make people know or don't know what is in your car. like twin or tripple plate clutches, diff's, etc. etc. etc.

if your that serious and ready for some work:

TII front cover, water pump and housings, FC CAS (re-wire to use this, Microtech or similar needed), and i cant remember, but i think some work to the oil pan is needed for the TII front cover.

then get the TII Gilmer pulleys... but this is a lot of work for some useless pullies. they do look awesome though!

As said above, get intouch with Green Brothers Engineering, in Tauranga here in NZ. These guys make alot of custom/aftermarket bits for early RX's through to the FD series, INCLUDING a Gilmer belt kit for the FD motors (all bolts etc included). As for belt slippage on the water pump, I think you'll be lucky to have slippage with such a big belt running against the pulley...
I've heard a few FD cars running with these fitted, sound amazing!!

http://i427.photobucket.com/albums/p...lrailkitFD.jpg
this is an example of what they can do

can't find a pic of the gilmers at the moment, when i do i'll post it up for you

I shot them an email last week. I haven't heard anything back. their website looks like its under construction so I guess i'm playing the waiting game.

their fab skills looks up to par so far.

Rich... don't forget to post up your findings on teardown. Would be curious to know the results.

found a pic of these gilmer kits, NZ$650

ditto and +1

can anyone post a link for purchase?

They don't make one for the 13B-REW (as sen2two already pointed out):

http://www.tweakit.net/shop/index.php?cPath=57_52_194

IMO, cogged (Gilmer) belts are ideally suited for high loads (dry-sump oil pumps, for instance), or, obviously, where the relative location of the pulleys is critical, such as cam drives, etc.

In cases other than these, they can and are used, but offer little advantage over the now common surpentine belts, other than not needing a tensioner in many applications.

:lol::lol::lol::lol::lol::lol::lol::lol:

I'm looking for a link to purchase from the greene brothers racing in NZ.

Look at your message. You asked for a link to purchase a kit, and quoted a post about the "Gilmer" pulley kits.