Garage Storage Organization and Garage Cabinets

**lotashelbys** · **Custom timing belt routing**

This was an idea that me and a few others have been talking about for about 6 or 8 months now and I finally did something about it. That is idler between the intake cam and I-shaft run of the timing belt. That is the worst spot for belt deflection and with the idler there I think it will dampen ALOT of that and hopefully keep the I-shaft teeth and and belts alive much longer.

I pulled the motor out of a buddies beater Spirit R/T earlier today(thats why its ugly) and it was just sitting on the cherry picker and I wasnt tired yet,hmmm....
Well a half an hour later and it was all mocked up. It fits like it was supposed to come that way with only grinding a few things off the cast aluminum alt/AC bracket and drilling a hole for the idler pulley and counter-sinking the P/S bracket for a flat head socket cap screw to take place of where the idler used to be. Yes,it still uses the stock belt and you can still run the A/C

Heres a few picks of the mocked up proto-type. I will have to put a prettier version in the next car that goes together for some road testing.....

**Screamin4banger** · **Re: Custom timing belt routing**

That definitely looks like it will keep that belt under control better

Just a few Q's:
How many degrees would you guess the cams are advanced with stock gears?
Do you feel having the idler threaded into the aluminum a/c bracket will last indefinitely?

Looks good

**bansheenut420** · **Re: Custom timing belt routing**

you sir, are THE man.

That is all....

**movaldes** · **Re: Custom timing belt routing**

Sign me up...

Would this change the tension setting on the belt?

Millerman340 · **Re: Custom timing belt routing**

Did it move over a tooth on the belt?

Pat · **Re: Custom timing belt routing**

It will move the cam timing around a bit also...make sure you use adjustable cam gears and get those babies degreed in.

**Blue Iroc R/T** · **Re: Custom timing belt routing**

IMO, you would still time the cam in the same manner as per the FSM, it is just that the slack on the front of the belt would be taken out by the idler on the front. If the crank is at TDC and the Cams are Set to TDC, and the belt is tensioned correctly; as the belt moves, SO will the cams. I don't see that the idler on the front will have any affect on the cam timing.

eski · **Re: Custom timing belt routing**

How about two smaller idlers. One in original spot and one in new spot?

Pat · **Re: Custom timing belt routing**

Quote:

Originally Posted by Blue Iroc R/T

IMO, you would still time the cam in the same manner as per the FSM, it is just that the slack on the front of the belt would be taken out by the idler on the front. If the crank is at TDC and the Cams are Set to TDC, and the belt is tensioned correctly; as the belt moves, SO will the cams. I don't see that the idler on the front will have any affect on the cam timing.

The cams will move a few degrees because if the crank is at TDC and you pull some slack out of the belt on the front side of the cams, it will move the cam gears a few degrees. Typically the slack is pulled out of the back side.

rx2mazda · **Re: Custom timing belt routing**

Quote:

Originally Posted by Pat

The cams will move a few degrees because if the crank is at TDC and you pull some slack out of the belt on the front side of the cams, it will move the cam gears a few degrees. Typically the slack is pulled out of the back side.

+1

**lotashelbys** · **Re: Custom timing belt routing**

Quote:

Originally Posted by Pat

The cams will move a few degrees because if the crank is at TDC and you pull some slack out of the belt on the front side of the cams, it will move the cam gears a few degrees. Typically the slack is pulled out of the back side.

I was thinking about that all day yesterday after what Millerman said and the worst it will do is advance both cam slightly and move the powerband down a few RPMs which wont hurt most TIIIs that arent heavily modified

Millerman340 · **Re: Custom timing belt routing**

But what I was thinking was that if it was exactly the space of one tooth then it should not change, I've been hoping for this fix since my first belt break.

kermit · **Re: Custom timing belt routing**

It might move it, it might not. depends on if the added distance is equal to an even multiple of the tooth distance. It should be off no more than one tooth.

You could fix this by adjustable cam gears, or make the new pulley adjustable so that you can set the distance right so the top and bottom line up.

**lotashelbys** · **Re: Custom timing belt routing**

So,this has been bothering me all week to see if this works so I had to try it. Just got back from the first test run in my white Spirit with the idler on the other side

It seems to run a bit smoother and ALL of the harmonics or belt slap on the rev-down is gone. I guess they should of made them this way just like every other DOHC motor out there. Heres some pics.......

**dragbaron** · **Re: Custom timing belt routing**

Any problems with it since August? Were you able to do this conversion on your car with the motor in place? If you have decided that this works with no problems, could you give some instructions on what all tools and parts are needed(drill bit and tap size, power steering bracket bolt, etc)? The belt is off my car right now, so i thought i'd ask.