Morris Minor Owners Club

Posted: **Fri Jul 22, 2022 12:04 pm**

Hi guys a little history recently go this 1970 traveller it had a full restoration in 2014/15
With supposedly a new engine the guy i bought it off bought it to store and its only done 500 since i now know not good.
Anyway it was very smokey on start up but is 99% better now not an issue.
It has developed a big end rumble and smoke on acceleration so i thought I've got to investigate so head off and was very surprised virtually no bore wear no lip on top of cylinders and i think standard pistons pics to follow. This is an 8g engine so i believe a gold seal unit
Do you think i would get away with cylinder honing deglaze and new rings ?
AFTER checking the big ends first hopefully ive caught these early ive only done a couple steady miles
Any advice appreciated thank you.

Posted: **Fri Jul 22, 2022 1:05 pm**

From the photos it does look like you may get away (assuming what looks like scratches in the bore hone out easily) with new rings and hone, to be sure you need get the pistons out and check the bores are parallel and round.

For the mains you may get an improvement with new bearings but I suspect if they sound bad you may need a new or re-ground crank. Basically if you can feel a ridge on the crank journal (the centre part does not wear because it runs in the oil groove) new bearings will only really be a short term fix.

Posted: **Fri Jul 22, 2022 1:22 pm**

I had a similar experience with my bores and pistons, I bought a set of rings which turned out to be unsuitable. No top ridge dodger. plain 2nd ring. 3rd ring if fitted according to the instructions had a ridge dodger at the bottom! Oil control rings were devoid of spring. Needless to say, I didn't fit them. I managed to obtain a set of Cords rings which were fitted and have stopped the smoking.
Sounds to me that your big ends are done for. Unless the crank journals are perfect, I doubt that new shells will be successfull.

Posted: **Sat Jul 23, 2022 6:48 am**

Thank you for your input appreciate it

Posted: **Wed Jul 27, 2022 9:22 pm**

NETTIE wrote: ↑Fri Jul 22, 2022 12:04 pm Hi guys a little history recently go this 1970 traveller it had a full restoration in 2014/15
With supposedly a new engine the guy i bought it off bought it to store and its only done 500 since i now know not good.
Anyway it was very smokey on start up but is 99% better now not an issue.
It has developed a big end rumble and smoke on acceleration so i thought I've got to investigate so head off and was very surprised virtually no bore wear no lip on top of cylinders and i think standard pistons pics to follow. This is an 8g engine so i believe a gold seal unit
Do you think i would get away with cylinder honing deglaze and new rings ?
AFTER checking the big ends first hopefully ive caught these early ive only done a couple steady miles
Any advice appreciated thank you.

The plot thickens are these 1098 piston please.
Ive just noticed the cylinder head markings as CAM4810
The engine number is 8g i presumed gold seal but why would you put a cam head on ??
Im stripping this at present bores are spot on crank shaft big ends like new and the jurnals. I will remove the centre main tomorrow and check that out.
I don't want to go any further if its not a 1098
Thank you

Posted: **Wed Jul 27, 2022 9:32 pm**

I suspect that the CAM4810 head has been fitted as it is a factory unleaded head. Ok on a 998cc or 948cc but small valves for a 1098cc. At the end of production by BMC/BL various parts were fitted to new and reconditioned engines. The CAM4810 head may have been fitted at the factory as it appears to be a Gold Seal engine. Some new 'A' Series engines were fitted with liners to get around the fact that they had porous blocks.
What is the block casting number which can be found below the rear cam follower cover?
The block casting number will confirm as to whether it is a 1098cc engine or not.

Posted: **Wed Jul 27, 2022 10:09 pm**

Thanks Phil 12A497 does that sound right theres not much else
Thank you

Posted: **Thu Jul 28, 2022 8:21 am**

That identifies the engine as a 1098cc unit.

Posted: **Thu Jul 28, 2022 8:53 am**

You are a true gent Phil a massive wealth of knowledge that I and im sure all the other members are very greatfull for thank you.
So I'm happy to proceed reconditioning the 1098 block and the CAM4810 head many thanks
Regards Alan

Posted: **Thu Jul 28, 2022 12:19 pm**

Would you recommend changing the CAM4810 for a 202 head then ??

Posted: **Thu Jul 28, 2022 4:42 pm**

Done a bit more today I'm not finding any issues yet i expected the big ends no wear at all so dropped the centre main same no wear at all its like its just been put together

Posted: **Thu Jul 28, 2022 4:49 pm**

All looks good to me.

The 12G 202 head will give slightly better performance but you will have to replace the exhaust valve seats with unleaded ones.
If you are going to change the head I would fit a 12G295 head skimmed by 0.060" and fitted with unleaded seats for the exhaust valves.

Posted: **Thu Jul 28, 2022 5:04 pm**

Can't thank you enough Phil
I'm thinking replace locking tabs on all the ends these are shot
I'm still tempted to deglaze and replace the rings while its stripped
Then replace the head hopefully that will stop it smoking
Only problem is i stripped it down because i would have put money on it having a big end issue no knocking no metallic sound just rumbling
Thanks again regards Alan

Posted: **Thu Jul 28, 2022 5:14 pm**

The locking tabs should be a once use only item. Replace every time they are disturbed.
It will do no harm to deglaze the bores. Just make sure that you spotlessly clean everything afterwards.

Posted: **Fri Jul 29, 2022 3:34 pm**

I'd be tempted to check the bearing clearances with some plasti gauge, bearing and shell look like new which given it rumbles makes me wonder if the machining has been done correctly or the right shells used.

Posted: **Fri Jul 29, 2022 3:46 pm**

Whilst you may be experiencing a perceived rumble the bearings and crank journals do not bear that out. By all means use a plasti-gauge to check the clearances.
What oil pressure did you have?
Having a oil pressure i.e. above 65lbf/sq in would indicate normal working clearances at the crank journals. Excessive clearances would show as low oil pressure.
Overall I do not think that there is much wrong with the engine but it is better to check out the clearances to give a clean or not so clean bill of health.
Phil

Posted: **Fri Jul 29, 2022 4:22 pm**

Thanks guys i totally agree with what your saying
No oil pressure gauge ( but there will be one after this )
I would have expected evidence of some damage given the engine hasn't had a spanner on it in 7+ years just started every now and then.I spoke to the last owner and he didn't even change the oil or filter.
I think for now I'm going to deglaze with new rings rebuild the bottom end engine still in car and change the cylinder head for something more suitable and run it for a while sounds to me it was never even run in
I will keep you updated and thank you again

Posted: **Fri Jul 29, 2022 5:39 pm**

One last question please
People seem to have issues with the esm piston rings what would be your preferred choice
Thank you

Posted: **Sat Jul 30, 2022 11:40 am**

Well theres one issue resolved just removed all the piston rings and all of the small oil drain holes behind the oil control rings blocked had to literally drill out so that should go someway to helping

Posted: **Sun Aug 07, 2022 11:12 am**

Eventually all done guys runs really sweet sounds like a proper minor
Thank you all for your assistance much appreciated.
Just a few pics still a little tidying up here and there.

Morris Minor Owners Club

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