Assessing an unknown engine

[Gary71]

I think the greasy fingerprints over the dishwasher tab box might be a clue….

It’s easier to clean the valves once you’ve stripped the heads. Pop them in a drill mounted on your vice then use another drill with a wire brush attachment and the they come up lovely. It also gets all the deposits off the back of the valve

Good luck!

[911hillclimber]

It is rare to see a 7 written the continental way in the UK so guess that could be factory.

The cylinder height are grouped in height sets and are numbered so.
You need all 6 to be the same.
This allows the base copper gaskets to be the same thickness keeping the top surface level for the cam carrier so in turn allowing the cams to turn freely…

All this matters.

I think Gary knows all the excuses to give wives to washing parts in the dish washer!

We don’t have such a thing, so I’m safe on that score.

The lumps of alum will be the bottom of the piston skirt, my 3.2 failed in the same way splitting the barrel from top to bottom.
check the crank case most carefully around the stud areas, one of mine pulled a stud on the cylinder, needed machining flat!

I found prepping the heads took ages, longer than anything else.

[neilbardsley]

Sry my main take away from this is no dishwasher in the HillClimber house hold!

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[911hillclimber]

True, the dish washer is me.
I’m cheap and reliable and never break down.

Best cleaning for me has been paraffin, more paraffin, WD40. Bag after drying.
Brake cleaner and then more just before assembly..

I used to buy it off eBay 10 cans at a time.

[Nine One One]

True, the dish washer is me.
I’m cheap and reliable and never break down.

Best cleaning for me has been paraffin, more paraffin, WD40. Bag after drying.
Brake cleaner and then more just before assembly..

I used to buy it off eBay 10 cans at a time.

That must make your dishes/cutlery/glass stink! Not tried Fairy or other brand of washing up liquid, think you are taking dishwashing far too seriously!!

[911hillclimber]

Ha!
Just read the way I detailed my post…
I’m on holiday, so slightly more disconnected than usual…

[RobFrost]

It's not measuring straight here due to me not being an octopus, but I measured the bore tonight and got a consistent 61.95 for each diameter in the case from end to end. And also best as I can tell with a straight edge, they're in perfect line. I think I need to put the case together to measure properly, and to get a measurement in the perpendicular dimension.

I haven't researched how to test straightness that precisely. I have a laser and some good optics which I think could be put to use



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[chris68]

Hi Rob, I think a custom machined straight bar and plastigauge might be a better way to check this. Do you really think it could now be out of true after line boring from factory? Or are you concerned that some apertures are worn due to spun bearings?
Cheers

[Gary71]

If you are worried take it to a reputable machine shop to check. I’m not sure even the best home methods will be close enough to either confirm or deny.

[RobFrost]

Hi Rob, I think a custom machined straight bar and plastigauge might be a better way to check this. Do you really think it could now be out of true after line boring from factory? Or are you concerned that some apertures are worn due to spun bearings?
Cheers

Hi Chris, thanks for the suggestion. I was going to measure the journals, shells and bore, but those plastigauges look perfect so I'll probably do both methods.

Where I said "it's not measuring straight" I just meant I wasn't holding the bore gauge perpendicular at the moment of taking the photo because I didn't have enough hands.

Re measuring straightness I guess you mean something like this: https://www.neilsentools.com/products/c ... aight-edge along with some feeler gauges ? I can see no bearings have spun, the surfaces are perfect. Apparently you do need to be careful with the mag cases which are prone to distorting out of true. One expert said "always line bore", another said "assemble it and see how it turns" and a third said "measure it".

[RobFrost]

If you are worried take it to a reputable machine shop to check. I’m not sure even the best home methods will be close enough to either confirm or deny.

I'm not worried - I think it's probably straight and true. I certainly won't have the experience of a machine shop who measure such things regularly. Although I will have the extra motivation that it needs to be bang on because it's "my car".

[911hillclimber]

I would still fit the crank back in with new main bearings, lub with assy oil and bolt it all up.
If it is tight you know for free the case is bent, the crank will be straight.

Then you know you need to do more.

The Head Shop can do all this for you Rob.
They will insist on clean case halves, and will use a real washer to get the crud off every external and internal surface.
Bolted together they will have the gear and the ‘touch’ the assess it. They are agents for plasti usage, so have it all!

Get the heads machined for twin plugs, if not used you just leave a set of plugs in the lower holes. They are there for later.

I’m sure some blocks are out of shape, some have been jacked-up in the bottom of the engine and worse over the 50 years or so.
They probably will weld the case corner that needs doing and machining flat, tapping etc.

You will have peace of mind once they have checked it over, but my money will be on fitting the crank back in with new mains, lube and bolt it up, all the bolts, and see.

[chris68]

Personally, think line boring again is way over the top unless you really need to. You'd also then be stuck with finding higher OD bearings. I'd measure as far as I can (plastigauge / bore gauge) then provided all looks good, assemble carefully with lube checking crank doesn't tighten up. That's what my dad taught me 35 years ago and he was doing it day in, day out.

Only time I've had an engine line bored is when fitting steel caps on a three bearing cast iron Ford block. This to stand higher forces at elevated revs.

[chris68]

Looks like I'm agreeing with Graham on this . Felt the same way about not replacing studs. If it ain't broke ...

[911hillclimber]

If nothing else Rob, I would ask Head Shop if they can do the case repair.
Mag alloy welding could be tricky to fix.