My clutch and engine rebuild HELP

[callyspoy]

Hello folks,
As promised, i have started the strip down of the engine ready for a few bits, but the main reason for engine removal was to have a proper look at the clutch, as i wasn't too convinced in the skills of the previous owner (not him, but more the fitter of said box)
My memory is escaping me, as it's been a while since i have done a clutch on a Minor, but can you confirm what the thrust and pressure plate should look like on a 948? I know the thrust is scrap (was it replaced when the gearbox was done last year?!) but i thought the 948 was supposed to have the "stepped" bearing? To confuse it further though, the box is a ribbed one.


Yes, not much carbon left on that bearing!!



Onto the pressure plate, is it supposed to flat across the front of the piece that contact the bearing? I wasn't sure if there is supposed to be a lip where the springs attach? If that makes sense. Driven plate looks good still though and i never experienced a slipping clutch.



In other news, head is off, blackplate, flywheel and ancillaries too. Tomorrow i hope to have cam in and the block pocketed, time will tell!

I will order the clutch bearing tomorrow am, so any help appreciated before then.

[bmcecosse]

I'm sure you know I'm going to advise AGAINST pocketing the block cally........

[callyspoy]

Ha, funny you should say that. The cam i'm fitting (246) has quite high lift for the spec, so the amound that would need sinking would be too much to be sensibly done, so a mild pocketing will prove adequate.
I've done the maths and it should be fine, ha!

Just the clutch issue!

[bmcecosse]

Which is why a high lift cam like that is not a good idea.....is it any better than a standard 1098 engine cam?? I doubt it....
Pocketing the block exposes the top ring too much.....and spoils the block for future use......

[liammonty]

Looks like a 948 clutch to me. You can measure to be sure, as the 1098 is an inch larger diameter (I think!). 1098 pressure plate is a domed shape, not flat like yours.

[callyspoy]

Right, progress has been steady this week.

Firstly, clutch mechanism.
Before it had the adjustable rod going onto a single one of the linkage plates then onto the pedal. A right mash up of rubbishness. Anywho, it now has a correct linkage with poly bush in there, had rubber once on my old Minor and it was pants, so poly was the only option.
Result is a slightly firmer pedal but a MUCH improved feel, which is nice.

Engine is now done too obviously, this was good fun to do. A little run down of what i have

*948 bottom end (+30), with crankshaft damper
*Kent 246 cam
*940 small valve head (pocketed block due to higher lift)
*hs4 on alloy manifold with an air filter housing similar to Triumph Herald but deeper, with k&n inside
*Ital twin exit manifold with normal "big bore" twin box from the regular suppliers
*lumenition electronic in 45d dizzy

That's the spec, and i have to say, it sounds and runs well. I need to do some tweaks to fueling and timing as i only got it in this afternoon, took it for a quick blast around the block and it does feel good.
Unfortunately, for the last week i have been driving my dad's Minor as he's on holiday, so my comparison is to that, rather than my own slow 948. It feels pretty similar to dad's at the mo (998,256 cam, worked 202 head, hif38, lcb, big bore exhaust), so i'm hoping some tweaks will give me a little bit more.

All in all, pretty happy with it

[callyspoy]

My head appears to be leaking oil near the tappet chest (it's not the tappet chest gasket) what could be the cause?

[MarkyB]

Give it a good clean before you try and find the leak, any that get spilled when filling may end up going over the tappet covers.

[callyspoy]

Tis is a fairly substntial leak unfortunately. May re-rorque the head tomorrow.
I had assumed it was the tappet cover leaking, so swapped out the gasket and cleaned it all off, once up to temp and driving, there was a fair amount of oil running down the side,
Now, having just had a look, it does appear to be coming from the front right hand side of the head, am i correct that this "could" be solved with a little torque down?
I assume my compression will have increased somewhat due to the 940 head so a slightly higher torque could be neccessary?
I am taking my friend to her wedding on Thursday, so ideally need it leakfree before then!

[bmcecosse]

Sounds like a problem with the feed to the rockers - check the 'rivet' in the end of the drilling is not loose....There is no other oil feed anywhere on the head. 44 ft lbf unless using the late head nut with washer combined......then 50 ft lbf IF you have the later /stronger studs to go with them......

[callyspoy]

Roy, can you confirm what rivet this is?
My dad is currently on his holidays and has suggested the same thing!

[callyspoy]

Spotted the rivet, dry as a bone.
It allears to be running along the front of the head to block face at the front and then dribbling down the tappet cover. I'm royally stumped though.
I will just have to take the head off tomorrow which is less than ideal due to the time constraits with the wedding, any other pointers would be HUGELY appreciated!

[IslipMinor]

If you haven't already done it, I would suggest that you get the engine up to working temperature, clean the rocker cover and everything around it and below it thoroughly - especially the area between the rocker cover and thermostat housing. Then restart the engine at a fast idle and with a really good light watch very carefully to see where the leak starts from.

I won't say never, but an oil leak from between the head and block is very unusual, even unlikely.

[callyspoy]

I too can't really believe that there is a leak between the two, i shall do as you suggest Richard amd report back. I have tried my best to have a gander though and it just looks like too much to have come from somewhere at rocker cover without me noticing :-S
Ideally i'd rather not take the head off!

[callyspoy]

Ok, had a proper clean and poke around.
It was definitely coming from the head gasket so i had no choice but to remove the head.
On removal it became apparent that the threads had stretched on the front right stud, which i can only assume is the cause of the oil leaking from the front oil channel/feed between block and head as it is very near to this.
Gasket and new studs/nuts/washers ordered, should be here tomorrow. Not ideal, but fingers crossed it'll sort it.

[bmcecosse]

Can't see it myself........but fingers crossed.......

[callyspoy]

Yes Roy, cross those fingers!!

[anubis121]

My head gaskets blown twice in two weeks now,got it repaired the first time and it blew again 10 mins after picking it up from the garage.They want payment to repair it again.

[callyspoy]

Yeah ijust saw your post, seems a bit ridiculous that they should want payment for it.
Head gasket can be done in an afternoon (quicker if in a hurry), so seems odd that they would be so hard on it, bearing in mind the amount of money you have just shelled out with them.

Back on mine, did the head gasket today, oil seepage appears sorted. Drove it around a bit more today and i am pretty happy, nice and smooth now. Here's hoping it goes okay for Thursday(the wedding).

Thanks for the kind words and offers of info!

[bmcecosse]

Was there anything obviously wrong with the gasket that came off?