19 replies to this topic

[zack88]

Hello all, not new to minis, but new to this forum. I hear it's the friendly place for help and advice.

 

Over the past months with restrictions in place i decided to overhaul the engine as the miles were building up (close to 80,000).

The block has been re-bored and new pistons fitted, crank re-ground and new shells. It's also had a new camshaft and followers and oil pump.

Head looked in good condition. I just had it skimmed to clean it up and cleaned and lapped the valves in.

 

Engine was put through a heat cycle ready to re-torque the head. When i shut the engine off i noticed water between the head and block.

Suspecting the head gasket i began to remove the head nuts to find they were only nipped up and not torqued down.

How i managed this error i do not know, but i called myself a few choice words for being such an idiot.

 

With the head off i noticed water down one of the bores, and down into the cam followers. I decided to rebuilt it, drain the oil and fit a new filter and oil to flush the system.

This time with the head torqued down i warmed it up again, then drained the oil. The head has been re-torqued

It had a new filter and oil and i've run it for the recommended 20 mins at 2,500 to bed everything in. Since then i have driven it for a couple of hundred miles  

 

Sorry for all the rambling, but i guess my question is, should i be pulling and stripping the engine to see if i have any premature wear.

It did have the required grease on the cam lobes etc.

 

tia 

[cal844]

It'll be OK.

Double check the torque on the head nuts then keep an eye on the head gasket line for weep, if there is no weep carry out a compression check and post results here.

I suspect all is well though

[MiniMadRacer]

Might be teaching to suck eggs but never ever re torque any bolt or nut without crackinig it off first, or it will never clap as you expect

[MiniMadRacer]

clasp

[cal844]

Might be teaching to suck eggs but never ever re torque any bolt or nut without crackinig it off first, or it will never clap as you expect

Yeah that would be advantageous ?

So when the engine is stone cold loosen the nut maybe 1/2 turn, then torque to spec.

Apologies for not stating previously

[zack88]

Thanks for the quick replies and putting my mind at rest with the engine.

 

I'll get it re-torqued and carry out a compression test.

Now, where did i put the compression tester !!!

[zack88]

Managed to get back onto the car today. Did a re-torque of the cylinder head and carried out a compression check.

All cylinder within 1 psi of 160, so all looking good there.

 

I've been re-thinking the engine build and can't remember putting any installation lube on the cam lobes before running it in.

The engine has a rattle through most of the rev range which i wouldn't expect being a new build.

 

Should i pull the engine again this winter and examine the followers and cam ?

What are peoples thoughts.

[cal844]

It is recommended to use assembly lube but if you run the starter to build oil pressure it should be OK.

What you can try is the screw driver trick, use a long screwdriver as a Listening stick or even better is getting an automotive stethoscope. Then you run the engine and use the stethoscope to pin point the noise

Edited by cal844, 27 October 2020 - 09:43 PM.

[Johnmar]

Then you run the engine and use the stethoscope to pin point the noise

While pressing your ear against the handle of the screwdriver. The localized sound vibrations/sound at the point of the screwdriver will travel up to the handle.

[cal844]

Then you run the engine and use the stethoscope to pin point the noise

While pressing your ear against the handle of the screwdriver. The localized sound vibrations/sound at the point of the screwdriver will travel up to the handle.

Yes that's the theory.... I should do better but got distracted ??

[zack88]

Thanks for the replies guys. Cal844, yep, remembered to get oil pressure up before the engine start :)

 

I'll see what screwdrivers i have in the garage.

 

 

 

It is recommended to use assembly lube but if you run the starter to build oil pressure it should be OK.

[gazza82]

Check that the rattle isn't the timing chain .. I fitted a duplex to a 1098 Midget lump and it was ultra noisy. I eventually swapped out the chain (which was new) and quietened it down.

[Dusky]

It is recommended to use assembly lube but if you run the starter to build oil pressure it should be OK.

No, it shouldn't. Building oil pressure on the starter only ensures some oil reaching the main bearings. Cam loves are lubricated by the oil splash coming off the conrods. That's why we need to keep the revs high on the first 20 minutes while the followers bedding in.

[cal844]

It is recommended to use assembly lube but if you run the starter to build oil pressure it should be OK.

No, it shouldn't. Building oil pressure on the starter only ensures some oil reaching the main bearings. Cam loves are lubricated by the oil splash coming off the conrods. That's why we need to keep the revs high on the first 20 minutes while the followers bedding in.

Would it be possible to put some oil down where the pushrod sit? Even just to rule out the camshaft, followers etc. If the other checks do not rule anything out, then I'd now be stripping the motor.

Edited by cal844, 28 October 2020 - 07:09 PM.

[Dusky]

It is recommended to use assembly lube but if you run the starter to build oil pressure it should be OK.

No, it shouldn't. Building oil pressure on the starter only ensures some oil reaching the main bearings. Cam loves are lubricated by the oil splash coming off the conrods. That's why we need to keep the revs high on the first 20 minutes while the followers bedding in.

Would it be possible to put some oil down where the pushrod sit? Even just to rule out the camshaft, followers etc. If the other checks do not rule anything out, then I'd now be stripping the motor.

You could pour assembly lube down those holes if you forgot it, yes. But after starting the engine the damage is done.