mission creep

[tonyk]

Following a previous post regarding incorrectly installed pistons, I eventually followed the advice of the "tear it down and rebuild it" opinion and reduced the block to its component parts. , initially to deglaze the bores for new piston rings.

I found wear on 2 main bearings with traces of cooper peeping through the white metal, slight circumferential scoring on some of the crank journals and maybe on some of the big end journals. It's off to the machine shop next week to see what the main man thinks of it. Probably a regrind - already on -20" thou - but shells are avilable at -30" and -40".

Also the bearing nuts were inconsistently torqued - with some being under - replace with an ARP set.

No internal gaskets on the oil pump with one stud missing!!
Felt oil seals soggy and friable replacements come in the gasket kit. distributor drive in wrong (or maybe the timing chain out of synch - no "bright" links), etc,etc.

Worn and grooved timing chain tensioner and deteriorated cover gasket - replace ? are rubber ones available? New rear crank oil seal and bits from DWR.

Cleaned the block out thoroughly, a lot of sludge, removed the core plugs to find a main waterway blocked.

Camshaft showed some surface breakdown on some of the lobes - sent it off to Piper for an opinion, they say it can be reprofiled with new followers, I know opinions differ but a new one is very expensive and the car is not used for racing. They're going to do a "fast road" profile to pep it up a bit (and maybe I can keep up with the wife's mini).

Anyway, The car had been in storage for some time and I got the impression of a grittiness on the surfaces of the crankcase and I was wondering whether tiny rust particles from may have contributed to the patchy bearing wear.

So does anyone know which is the best paint to use inside the crankcase for future protection? and there are traces of the original red/maroon paint - what shade is "correct"? I'll do it while it's stripped.

Also does anyone know the normal depth of the cylinder head (late BJ8 with AEC960 casting). I think I saw something on this but I can't find the post. Reason for asking this is that, sometime in the past, the head was ported out(ideally requires a slightly larger than standard manifold gasket), the machinist pointed the marks left by this, and it has been skimmed down so that combustion chambers are 48cc (greased up the plug recesses and around the new valves, all watertight)syringe, plastic cover plate).

With a mildly reprofiled cam, in this situation, valve pockets may be required but careful measurements will need to be made for clearance.
I'm told that, normally, there is lots of room but the lift will increase from 0.368" to 0.400"
I,m hoping to get away with it but it has to be checked.

To anyone reading through this thanks and thanks ,in anticipation,for information.

One last point for now, I was talking to the guy at DWR about lightening/balancing the flywheel while it's out. He, being a purist racer, said it would be best done, if at all, with the clutch assembly as a unit. There have been many threads on this topic, with as many opinions, but for road use should I get it done as a one off?

 

[57_BN4]

Hi Tony,

Some semi random thoughts from my 100/6 engine rebuild if they are helpful to you:

There are two sludge pits in the tappet chest which are almost inaccessible behind the areas between the three side plates. A good hours work to get them cleaned out fully.

Balance the entire crank, flywheel, clutch and front pulley- they weren't very well balanced to begin with. Lighten and surface the flywheel first if you are going to.

Index grind the crank B-E journals to the correct stroke if you are going to grind it. My crank has the middle two pistons stroking 0.43mm longer than the rest due to sloppy machine work. I am going to replace the crank since it is already -0.020.

If you haven't already, replace the OEM oil filter housing with a spin-on job. There is a filter bypass valve in the OEM housing that gets dirt in it and sticks open sending unfiltered oil to the bearings. It along with the DPO doing a fairly sloppy rebuild ruined my engines bearings in less than 2000km

Check the cam bearing clearances. Mine, like the crank bearings were badly scored and I replaced them with a NOS set which required line boring. Some don't.

Get hold of multi-piece oil rings, the cheapy one piece type aren't very good. One of mine got broken due again to DPO handiwork but fortunately hadn't damaged the bore. Total Seal Gapless rings are available for Healeys.

Check the oil pump clearances, particularly the end float. Reduce it to spec by lapping the pump housing. Check the lower shaft bearing is not worn in the housing.

If you end up having machine work done on the block, deck the top face down so the pistons are flush at TDC, or just below it. This will help reduce detonation.

Andy.

 

[tonyk]

Hi there BN4
Thanks for the reply.

I saw something about the "sludge pits" you mention in someone elses rebuild photo diary (I did a lot of reading before starting this)- it wasn't yours was it?. I made a special point of clearing every nook nand cranny with degreaser, pressure spray, rinsing and then an oil spray nto stop rusting.

There aren't many, if any places near here that do extensive balaancing as you describe, that's why I was going to have to send the flywheel away.

Don't know what index grinding is. I'll have to see what the machinist says.

I put a spin on oil filter a while back. I took out the oil pressure relief valve (1,1/8"th socket same as the sump plug). The spring was 1/4" shorter than a new replacement.

I'll have to wait till the cam comes back to check clearances of the bearings. They look OK. I'll see if if the guy at Piper grinds down the journals, if so definite replacement.

I'm going to check the oil pump end float as per the manual later when it goes back together.

The pistons came to the top of the bores before dismantling. The original factory size stamps are clearly visible so I don't think it's ever been decked.

Thanks for the thoughts.

 

[Patrick67BJ8]

Hi Tony,

Some semi random thoughts from my 100/6 engine rebuild if they are helpful to you:

There are two sludge pits in the tappet chest which are almost inaccessible behind the areas between the three side plates. A good hours work to get them cleaned out fully.

Balance the entire crank, flywheel, clutch and front pulley- they weren't very well balanced to begin with. Lighten and surface the flywheel first if you are going to.

Index grind the crank B-E journals to the correct stroke if you are going to grind it. My crank has the middle two pistons stroking 0.43mm longer than the rest due to sloppy machine work. I am going to replace the crank since it is already -0.020.

If you haven't already, replace the OEM oil filter housing with a spin-on job. There is a filter bypass valve in the OEM housing that gets dirt in it and sticks open sending unfiltered oil to the bearings. It along with the DPO doing a fairly sloppy rebuild ruined my engines bearings in less than 2000km

Check the cam bearing clearances. Mine, like the crank bearings were badly scored and I replaced them with a NOS set which required line boring. Some don't.

Get hold of multi-piece oil rings, the cheapy one piece type aren't very good. One of mine got broken due again to DPO handiwork but fortunately hadn't damaged the bore. Total Seal Gapless rings are available for Healeys.

Check the oil pump clearances, particularly the end float. Reduce it to spec by lapping the pump housing. Check the lower shaft bearing is not worn in the housing.

If you end up having machine work done on the block, deck the top face down so the pistons are flush at TDC, or just below it. This will help reduce detonation.

Andy.

My oil pump gears had some wear but not a lot and I just sent them to the CAD plater to be CAD plated and baked. I'm presently doing a rebuild on my engine and since it's been 1976 since I rebuilt Healey engines I've forgotten some of the "look for" stuff but it's all starting to come back to me. THanks for lots of "details" in your post! Not sure about lightening the flywheel, but I may change my mind later on that.

 

[Bob Claffie]

Mea culpa, I am one of the posters to your original thread. I suggested "leave it and drive it" , from what you found that would have been not good advise.

Lightened flywheels , some good , some bad. Initially good as it allows the engine to accelerate more rapidly as you're not trying to speed up a 30 lb lump of steel, secondly it will make starting from a stop slightly more difficult because there is less inertial momentum from the heavier flywheel.

Lastly, depending on the grind/profile of the cam machining you may have to diddle with the rocker geometry due to decreasing the base circle. Likewise look at possible valve spring bind due to the higher lift. Bob

 

[Deleted member 8987]

Paint. Some use Glyptol, I use Rustoleum red primer. I cut a flat plastic lid to stick in the bores to sort of protect them, a quick wipe down with spray carb cleaner on a rag will take overspray off. Same with mains stick old lifters in the bores to protect them, then do the pan and inside of the bare timing cover and side cover.
I used to get a lot of flack for spending the time when I rebuilt Flathead Fords for folks....until their buddies ended up with another rebuild because rust went through the engine.
Never hurts to paint....often hurts not to.
Dave

 

[tonyk]

Hi there
To Bob OH Gawd I hope this cam change isn'yt going to get too complicated. I had new valve springs fitted when the head was renovated recently. I know the cam timing etc will have to be adjusted - and it's a good opportunity to get TDC precise and, as BN4 said, check the maximum rise of the pistons in the block.

To TOC. OK I think it would be safer to protect the internals. Looks like it's an epoxy so should be restintant to corrosive compounds. One thought - would you paint the con rods and crank weights (obviously avoiding the journal sufaces) for the same reasons? Or is this overkill.

 

[elrey]

Overkill, just Glyptal the non machined areas of the block. And the interior of the tin if you wish, but do not paint the moving parts within the engine.