Fan clutch to waterpump issues

[H8DAG8]

Hi guys

1984 Sigma, 2L 4g63 SOHC carby 8 valve engine (RWD).
Just putting the last of the stuff together after an engine overhaul now that my water bypass pipe FINALLY arrived from japan and ran into an issue.

How hard should the fan clutch be to put onto the exposed bolts from the waterpump?
It's a new waterpump so not the one that was previously on it, and it's the old fan and fan clutch.
The bolt holes etc all line up with the waterpump pully and waterpump bolts but I'm pretty sure it's the center dowl (I think that's what it's called?) of the waterpump being a fraction too large for the hole in the fan clutch.

Has anyone run into this problem before? I've rubbed some vasaline around the dowl to try and help it in there but it's just too big (just!) so as I tighten the nuts it just pivets and then stops and won't tighten any more - whilst being about 5-8mm off the pulley so not holding it on there.

What would be the easiest solution? I got an engine reconditioner to do some work on it and they got the waterpump and installed it but surely they got the right one because everything else fits fine, just not the fan clutch.

Everything closed now so can't call anywhere.

Any help MUCH appreciated!

Thanks:)

[H8DAG8]

Help?

I'm not an engineer so don't want to try drill the hole in the fan clutch bigger as if it's off center by a fraction I'm assuming it will cause major vibration in the fan and probably other parts too and most likely wreck something.

No one has run into this issue before? Don't for the life of me know why Mitsi would make the new fuel pump so the frickin dowl is bigger than the hole in the old original fan clutches!!

[geezer101]

Is there a parts listing for clutch fans somewhere? Maybe a variation between triton/sigma/L200? Might be easier to track a matching clutch fan for your water pump...

[H8DAG8]

Is there a parts listing for clutch fans somewhere? Maybe a variation between triton/sigma/L200? Might be easier to track a matching clutch fan for your water pump...

So you'd recommend trying to find a fan clutch (and possible fan too) that will fit rather then boring out the hole on my current one?
And even if I do get a different fan clutch for a Sigma wouldn't it be the same as my current one and not fit? Just seems odd to me that they don't match but they are both obviously off a Sigma 4g63 engine!

[geezer101]

These engines wound up in a couple of different vehicles so there could easily be some subtle differences between them. There could even be differences from JDM and local parts. I ran into a sitution where a friends alternator gave up so I picked up one from the wreckers that was missing the mounting bushes pressed into it. Knocked the bushes out of the dead alternator and tried tapping them in to the new one- bushing holes were slightly smaller and wouldn't go in. The joys of motoring... Me personally, I prpobably wouldn't be game enough to run a drill through the centre of the clutch assembly either!

[H8DAG8]

These engines wound up in a couple of different vehicles so there could easily be some subtle differences between them. There could even be differences from JDM and local parts. I ran into a sitution where a friends alternator gave up so I picked up one from the wreckers that was missing the mounting bushes pressed into it. Knocked the bushes out of the dead alternator and tried tapping them in to the new one- bushing holes were slightly smaller and wouldn't go in. The joys of motoring... Me personally, I prpobably wouldn't be game enough to run a drill through the centre of the clutch assembly either!

Hmm, now that I think about it knowing Mitsi there probably are variations in the same parts depending on when they were made!
I'll give the engine recon. place that de-balanced my engine (and also purchased and fitted the new waterpump etc.) tomorrow and see what they say - I'll try make it their problem ;)

[geezer101]

Well, they did supply it. Technically it is their problem. If they can cross refer the part numbers they should be able to work out why it doesn't match your fan assy. If not, say hi to Mr thermo fan! It will make the engine bay look less cluttered and free up your revs a little too (plus take some strain off your water pump bearings). I know some guys say they don't work as well as the pump mounted fans but you can always fit up a missile switch as an emergency over ride to run your fan whenever the cooling looks like it's struggling. I set up one in my Galant wagon and even had a water micro sprayer running off an old washer bottle onto the radiator as a fail safe (adelaide gets FREAKIN' HOT!)

[H8DAG8]

Well, they did supply it. Technically it is their problem. If they can cross refer the part numbers they should be able to work out why it doesn't match your fan assy. If not, say hi to Mr thermo fan! It will make the engine bay look less cluttered and free up your revs a little too (plus take some strain off your water pump bearings). I know some guys say they don't work as well as the pump mounted fans but you can always fit up a missile switch as an emergency over ride to run your fan whenever the cooling looks like it's struggling. I set up one in my Galant wagon and even had a water micro sprayer running off an old washer bottle onto the radiator as a fail safe (adelaide gets FREAKIN' HOT!)

HAHAHA love it. Yea was thinking about an electric fan but didn't really want to fork out the extra $$ after all the money I've recently spent on the panel and paint AND then the engine cracking and blowing up on me.

Will see what they say on Monday and if they are still w*nkers then I'll have to look into getting an electric one. How would I go about doing that? What's involved?

[81GL]

Have you got some vernier calipers? or better yet a micrometer set?
Would be interesting to measure the two surfaces and see what the difference is.

Wouldn't be too much work at all to slightly open up the hole in the clutch to suit; would require a lathe to do it properly though.

Setting up a thermo fan is pretty easy, but... not really as effective on our cars set up when you live in a warmer area. All I'm going to say here is, never skimp on the cooling system, if you do end up going for an electric fan, spend a few and get something decent.

[geezer101]

An upgrade to an electric thermo fan can be done on a reasonable budget. About $75- $100 for an 11" thermo fan kit ($100 will get a kit with wiring and relay), about $20- $25 for an "in hose" adapter for the sender unit, add $10- $20 for the sender unit and extra hardware. Get a fan that's reversible (can be set up to push or pull air through). I'd mount it in front of your radiator. As for it cooking your engine- only if you botch setting it up... and you're not watching the temp gauge! All late model cars run electric thermos and redicuously thin radiators and they work efficiently enough.

[H8DAG8]

Thanks for the info. guys. Unfortunately no I don't have vernier calipers or a micrometer set otherwise I'd have it suss'd by now ;) and the 2 engineers that I know that do live close to me are both away overseas as my luck has it.

I'm going to try and match a bolt to the size of the dowl today, and go and buy or borrow a drill bit that matches and drill out the fan clutch to see how I go.
Hopefully it all works out, if not - I haven't really lost anything as I was going to have to get a different fan clutch or a whole new elec. setup anyway.

Will try and keep it as is for now - but if I HAVE to .. I'll go elec., just don't really want to fork out more $$ for it right now, has cost enough as my daily driver over the last 6 months (4.5 of which it hasn't been able to be driven)

Cheers!

[81GL]

Not meaning to sound rude, but probably not worth the trouble of finding a twist drill that will do it. My guess is you would have a difference of .2mm or .3mm, something small. drill bits arn't really available in those increments (unless you have an awesome shop/shed lol).

Just wait till Monday and see what your engine builder says about it

[H8DAG8]

Sorted it. Got sick of waiting so just put a drill bit in a high powered drill and went round as smoothly as possible once, then tested, then repeated, then tested, after 3 tries got it perfect.

Cheers

[bruggz351]

[geezer101]

I had visions of it grabbing and blasting it's way straight through the fan's guts! Nice work.