[car_overhaul] Track Hack Refesh & Tidy Up.

[Anthony 1,003]

How would the alloy pulley for the alternator belt effect the cambelt?

The rear of the pulley helps to locate the belt, and certainly if you're foolish enough to start the engine briefly without the pulley on, the belt quickly attempts to work itself off the pulleys. My thought was that if the way it has been designed means that the belt has more room to move, that will explain why it's trying to work its way off the cam pulley and tensioner, and is one of the things that you've changed since the old engine that hasn't been ruled out.

[pug_ham 244 3 Cars]

Ok, fair point.

 

The pulley has always been fitted & crank bolt tightened correctly before I've even turned the key but this is one of Tom's alloy pulleys the same as I had on the old engine without any issue & afaik is an exact copy of the original one.

 

Plans are now up in the air since I removed the head off my old engine & discovered what was the cause of my low compression on #3 cylinder.

 

Head off & the head gasket is still nice & clean;

 

 

Turned the head over & immediately spotted the cause;

 

 

Question is should I now simply do the rebuild on the old engine using while the head gets fixed & swap straight over to that?

 

g

[Paul_13 212 1 Cars]

Bloody hell, proper job with that valve head Graham!

[Tom Fenton 1,542]

The rear of the pulley helps to locate the belt, and certainly if you're foolish enough to start the engine briefly without the pulley on, the belt quickly attempts to work itself off the pulleys. My thought was that if the way it has been designed means that the belt has more room to move, that will explain why it's trying to work its way off the cam pulley and tensioner, and is one of the things that you've changed since the old engine that hasn't been ruled out.

 

Disagree there, the belt should run true and does not rely on the pulley to hold it on. I have run engines without the lower pulley and the belt tracks as it should. If the pulley did hold the belt on this would wear away the edge of the belt and also polish the side of the pulley. Neither of these should happen.

[Anthony 1,003]

Fair enough, maybe there was another issue with that particular engine - certainly it did try and throw the belt with the pulley missing, but gave no problems or abnormal belt wear with it fitted, hence suggesting it as something that was worth checking if the pulley was new to this engine.

[welshpug 1,661]

can only think it'll be due to misalignment somewhere, either the tensioner back plate bent, water pump pulley not true, or as Tom mentioned an out of square head which isnt unheard of unfortunately.

[marksorrento205 80]

You did say I would laugh at the pics Safe bet you know what was causing it then

[pug_ham 244 3 Cars]

Bloody hell, proper job with that valve head Graham!

Yeah, it was nice to see what was wrong as soon as I lifted the head off & turned it over.

 

You did say I would laugh at the pics Safe bet you know what was causing it then

, was i wrong?

 

Funniest thing is that the last time anyone off here saw this car would probably be at a Cadwell trackday last year & it was suffering the low compression issue then!!

 

Lasted through the day & a few weeks longer until I ripped it out to start this work.

 

Even though the water pump is new, I'm tempted to try another new one (this time the right one for this engine & not the later one with built in belt guard) just to see if it is the head or not.

 

When I swapped the tensioner I swapped everything over from my old engine to this one where it tracked true so unless the block or tensioner studs are bent it must be the head or water pump as they are the only two parts left except the whole bottom end.

 

g

[pug_ham 244 3 Cars]

I bought a new Motaquip (iMi) water pump yesterday & will be fitting it this week hopefully.

 

My reason for doing this is because I'm sure I've read on here that the later XUD7 & XU10 pumps are very slightly deeper so I'm going to do some measuriing when I get this one out & see if there are any minute differences that could mean the pump isn't sitting completely true.

 

Fingers crossed.

 

g

[pug_ham 244 3 Cars]

Cracked on & swapped the water pump yesterday so hopefully today I'll get it refilled with coolant & run up again to see if the belt is still being dragged off.

 

I measured the internal edge & the new pump was deeper than the "wrong" pump I removed but it turns much easier than the one I removed when fitted.

 

g

[pug_ham 244 3 Cars]

Well, another update on the continuing wandering belt saga.

 

I split the skin down my r/h ring finger when I trapped it between a trailer handle & towbar last monday & even though I got the water pump swapped, trying to do it all left handed failed so I kept opening the split & then decided to give it chance to heal before I got it all back together.

 

I've done that this afternoon & fired it up again, next step looks to be the head coming off because its still on the move when the engine fires.

 

In the five minutes it was running, I messed with my idle speed taking it down to an indicated ~650rpm, then I put the lights etc on & blipped the throttle just to see. It didn't stall!!

 

I'm moting a car tomorrow afternoon so I might not get it apart until after that (off to swap the droplinks later) but once it is apart I'll take the cam out & have the head checked over, I think having this one skimmed to level (if its out) is going to be quickest & then I'll focus on the other head while I do that engine.

 

I have got an XU10 head though...

 

g

[pug_ham 244 3 Cars]

I've made my mind up, I'm getting four new exhaust valves for fitting into my previous head (only approx 10k since refurb) & having the valve seats cleaned up/ valve relapped & then swapping over to that head.

 

I'm going to remove this head today (hopefully) & will take it along for checking when I drop the head in for the new valves fitting / lapping in.

 

Could all be back together within a week once the new valves turn up.

 

I just need to remove an old valve & measure it, apparently there are two valve lengths, 104mm & 108mm so I need to know which I have fitted & get the same

 

g

[pug_ham 244 3 Cars]

More (slow) progress, I haven't removed the suspect head from my car yet after deciding to get the old one rebuilt & ready to fit before I do.

 

I stripped that head down last week so I could check the valve stem length & be certian to get the right valves.

 

 

All the valve seats need cleaning but I need to lap the new valves in anyway so I'll do them all at the same time.

 

 

 

 

 

A nice parcel arrived yesterday;

 

 

Four nice new Renu automotive exhaust valves so I just need to get a valve lapping tool, some grinding paste & marking blue to check they are all sealing right before I refit the springs, collets etc to start the fun of valve clearances again.

 

g

[calvinhorse 870]

Any updates G?

[pug_ham 244 3 Cars]

Yes, the engine rebuild has been finished for a while & is now going into another 205.

 

I thought I'd updated the topic more than this but I'll dig out the photos etc of the rebuild & post them up soon.

 

g