New Problem with my FP Miata

H

HPMotors

Member
Just had a bad weekend at CMP - New engine3 tune, runs great, then the alternator/water pump belt jumps off. Checked it out, put belt back on and off she came again. This time I think I overheated the engine.

Stock pump, crank pulley and alternator - alignment looks perfect. All Mazda bits. The outlier, is that we were able to twist her up to 9k.

Anyone else seen this issue? Been running Miatas for quite a while, and this is a new one for me.
Henry
 
Check to make sure the crank pulley and water pump pulley run true. You really shouldn't be running those rpm's with any of that stock stuff fyi.
 
Not sure what caused it to come off, but alignment of pulleys does not appear to be the problem. Checked visually, with straight edge and small rope. All looks good. Ditto with the alternator - spins freely with no binding, noises or discernable abnormality.

Best plan now is to change to multi rib belt. No issue with the alternator or water pump pulleys as 1.8 pieces fit. Problem as I see it is getting a multirib pulley for my SNC harmonic balancer. Don't know if any off shore 1.6's had a multirib belt, but fairly certain there isn't one avalable for the SNC. Guess I will just bite the bullet and put a long nose in.

Any ideas on an electrically operated water pump? Convert alternator to dc motor and run a gilmer belt? This option seems to require a total discharge battery system which is another problem to design around. Mount electric motor directly on the water pump?

cheers
Henry
 
GT6 said:
Have you read pg. 460 of current GCR?
Click to expand...
m. Other Engine Components
1. The use of alternate engine components which are normally expendable and considered replacement
parts, such as fasteners, gaskets, seals, bearings, water pumps, etc., is permitted. Electrically
driven water pumps are prohibited.
 
I've got the November 2024 GCR in my hands, and (.1.5 Production Category starts on page 471, which is Level 1 Prep. Page 476 starts level 2.

However, the section m is what you quoted and despite looking for the mention of electric water pumps, i had missed it when I started this idea. Mea Culpa.

Good thing I don't have done anything other than research on the electric pump idea. Thanks for the heads up.

So, back to my problem. How do I put a multi rib pulley on my 1.6 with the short nose crank? Obviously, next engine will have the LNC but I've got this one in the car and the next event is in 3 weeks.

Other ideas as to keeping the v-belt on my engine are welcome. I am just guessing that the multi rib belt would better handle the high rpms.

Henry
 
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I don't see the November 2024 GCR.

How did you get that soo early?

There's always the option to make your own pulley.
Many people will create a 3D model for you and many quick-turn job shops will make the part for you.

Maybe you could add/bolt/weld guild washers to your existing pulleys? That way the belt has to stretch much further before it jumps off.
 
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