Assessing an unknown engine

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RobFrost
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Assessing an unknown engine

Post by RobFrost »

A recently bought 1970 2.2E engine arrived today - I allowed the auction house to hang on to it for over a month, due to lack of space. It's an unknown quantity - from a deceased estate in Scotland, a proper hoarder's property which I'm told had over a hundred cars on it at one point. The engine was dry stored in a cupboard in a garage and is good and oily, so corrosion doesn't seem to be a major issue, however I learned today it has been stored with the spark plugs out - that's something of a dissappointment.

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Anyhow, what's the protocol for assessing the condition of the engine? I'm thinking scope the cylinders, see if it turns over, take the covers off and check the cams, and if all seems good, maybe see if it runs - most likely with Webers on, initially. The MFI all turns freely. What do you advise?

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This stud is broken off and has taken part of the case with it, right? Once the stud's out, can the case be welded here? What's the solution?

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Anything I should do to prevent causing damage to the engine?

Image

Once cleaned up is there a treatment to prevent corrosion of the case, which is magnesium. I presume?
Last edited by RobFrost on Tue Mar 19, 2024 3:38 pm, edited 4 times in total.
1970 911T, Signal orange (Restoration thread)
1988 3.2 Carrera backdate, Black
2001 996 Turbo, Lapis blue (am I allowed to put that here?)
I'm looking for a pre-impact bumper 911S or other high-revving 911 to restore - please let me know if you see one.
911hillclimber
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Re: Assessing an unknown engine

Post by 911hillclimber »

If I was faced with that:

Get engine on a rotating stand
See if it turns over more than 1 revolution. If not then you won't be doing much else except putting some deisel into the cylinders and return to it a few days later and try again.
Assuming it revolves..
TDC on #1 and do a leak down test, listen to see if there is any hissing from the inlet, exhaust and engine breather, (valves leaking and/or rings leaking.
Do this on all 6 and make a note about each one.
If nothing excessive or very uneven across the 6 pots check the cam conditions etc
Keep testing everything.
If brave, put starter on the engine and crank it over for a few revs.

Tricky to actually start it without an oil system fitted.

If all seems to be correct I personally would do a top end rebuild, but depends what you want from this engine Rob.
73T 911 Coupe, road/hillclimber 3.2L
Lola t 492 / 3.2 hillclimb racer
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RobFrost
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Re: Assessing an unknown engine

Post by RobFrost »

I am led to believe the protocol for the broken mounting stud is to tig fill with AZ92A magnesium filler, bake out welding stresses at circa 200 Celcius for an hour or so, machine flush and redrill and tap the hole. Assuming nobody has information conflicting with that, does anybody have any suggestions of a good welder (preferably in the Midlands) who has experience welding mag cases?
1970 911T, Signal orange (Restoration thread)
1988 3.2 Carrera backdate, Black
2001 996 Turbo, Lapis blue (am I allowed to put that here?)
I'm looking for a pre-impact bumper 911S or other high-revving 911 to restore - please let me know if you see one.
911hillclimber
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Joined: Mon Mar 10, 2008 6:26 pm
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Re: Assessing an unknown engine

Post by 911hillclimber »

Possibly a call to Angus at Greatworth Classics Rob?
Sam there does the engine/boxes for Angus and has RedTek background too so must have seen this kind of damage before.

Magnesium alloy is a very rare material now, so many will have not seen it before.
Do not trust anyone in the wheel refurb 'trade' as they do not understand the metallurgy side, 'Mag Alloy' is not magnesium!

Not West Mids but no too far away is a wheel repair (motorsport etc) specialist, Jemiso Engineering , who may be worth a good look/chat.

I've used him to straighten my Lola's magnesium wheels, no welding, but he gave me great confidence (about 10 years ago). Wheel still good.

I think he is in York, does it by post too.

https://www.bing.com/ck/a?!&&p=48d418ed ... bHMv&ntb=1

Via Google, these people look good:
ABR Specialist Welding, West Bromwich
enquiries@ abrspecialistwelding.co.uk
73T 911 Coupe, road/hillclimber 3.2L
Lola t 492 / 3.2 hillclimb racer
Boxster 987 Gen II 2.9
anglophone1
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Re: Assessing an unknown engine

Post by anglophone1 »

911hillclimber wrote: Fri Mar 22, 2024 4:54 pm Possibly a call to Angus at Greatworth Classics Rob?
Sam there does the engine/boxes for Angus and has RedTek background too so must have seen this kind of damage before.

Magnesium alloy is a very rare material now, so many will have not seen it before.
Do not trust anyone in the wheel refurb 'trade' as they do not understand the metallurgy side, 'Mag Alloy' is not magnesium!

Not West Mids but no too far away is a wheel repair (motorsport etc) specialist, Jemiso Engineering , who may be worth a good look/chat.

I've used him to straighten my Lola's magnesium wheels, no welding, but he gave me great confidence (about 10 years ago). Wheel still good.

I think he is in York, does it by post too.

https://www.bing.com/ck/a?!&&p=48d418ed ... bHMv&ntb=1

Via Google, these people look good:
ABR Specialist Welding, West Bromwich
enquiries@ abrspecialistwelding.co.uk
Sam at Greatworth is an engine rockstar- just dont tell him I said so?
C
Clive
West Cork, Ireland

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1977 924 2.0 on Webers street legal race car - Martini 924
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911hillclimber
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Re: Assessing an unknown engine

Post by 911hillclimber »

Ha!
Looks like a bass player to me.
Cool, calm and collected in the second row back!

Does that make Angus the grumpy Lead Singer?
73T 911 Coupe, road/hillclimber 3.2L
Lola t 492 / 3.2 hillclimb racer
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neilbardsley
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Re: Assessing an unknown engine

Post by neilbardsley »

Google suggested these chaps

https://conceptracing.co.uk/contact-us

I have no experience with them

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Re: Assessing an unknown engine

Post by jwhillracer »

neilbardsley wrote: Sun Mar 24, 2024 6:48 pm Google suggested these chaps

https://conceptracing.co.uk/contact-us

I have no experience with them

Sent from my 22011119UY using Tapatalk
They are wonderful guys, but they don't do engines ..........

So much for Google :roll:

JW
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RobFrost
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Re: Assessing an unknown engine

Post by RobFrost »

I put a 19mm socket on the crank on Sunday and tried to turn the engine, but I found myself tightening and loosening the pulley bolt instead. Buying an unknown item in an auction, there's always a chance you're paying to take somebody else's problem away. So it was with some trepidation I ventured into the innerds. Top cam covers off revealed a little white corrosion (magnesium oxide) on the underside of the covers, but all in all a nice clean engine, good and oily with no signs of moisture.

The missing spark plugs however were a cause for alarm, increasing the risk of moisture entering the cylinders, and icnreasing the risk somebody has had a peep inside and been discouraged from putting the motor in a vehicle. I took a closer lookwith my cheap Amazon endoscope.

Three looked okay but to my eye these look like:

A bit of water in the bottom and a bird dropping.

Image

A bit of solder trapped under the edge of the piston and a broken piston edge.

Image

A barnacled ship with a crack right through the hull.

Image

Now i accept these are not the finest Nikon optics but can any more-experienced eyes tell me what they're seeing here?












1970 911T, Signal orange (Restoration thread)
1988 3.2 Carrera backdate, Black
2001 996 Turbo, Lapis blue (am I allowed to put that here?)
I'm looking for a pre-impact bumper 911S or other high-revving 911 to restore - please let me know if you see one.
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jb
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Re: Assessing an unknown engine

Post by jb »

The last one looks like a valve stuck on a piston
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hot66
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Re: Assessing an unknown engine

Post by hot66 »

That’s not pretty. No matter how you look at it, I think you’re stripping this engine fully apart . Gives you a good opportunity to upgrade to Spec etc though if that’s what you fancy. You’re going to need to put some money into it though
James

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911hillclimber
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Re: Assessing an unknown engine

Post by 911hillclimber »

Yes, agree, and I said that before, but, it is all very DIY, just need the Dempsey book and a few special tools and a Machine Mart engine stand.
If the pistons/cylinders are damaged then the costs escalate dramatically, but can't T barrels be bored? (a small amount)
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MikeyC
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Re: Assessing an unknown engine

Post by MikeyC »

RobFrost wrote: Mon Mar 25, 2024 9:37 pm I put a 19mm socket on the crank on Sunday and tried to turn the engine, but I found myself tightening and loosening the pulley bolt instead. Buying an unknown item in an auction, there's always a chance you're paying to take somebody else's problem away. So it was with some trepidation I ventured into the innerds. Top cam covers off revealed a little white corrosion (magnesium oxide) on the underside of the covers, but all in all a nice clean engine, good and oily with no signs of moisture.

The missing spark plugs however were a cause for alarm, increasing the risk of moisture entering the cylinders, and icnreasing the risk somebody has had a peep inside and been discouraged from putting the motor in a vehicle. I took a closer lookwith my cheap Amazon endoscope.

Three looked okay but to my eye these look like:

A bit of water in the bottom and a bird dropping.

Image

A bit of solder trapped under the edge of the piston and a broken piston edge.

Image

A barnacled ship with a crack right through the hull.

Image

Now i accept these are not the finest Nikon optics but can any more-experienced eyes tell me what they're seeing here?
Ultimately, Rob, I don't think there's any need to guess further on this one. The details shared so far show that the engine needs stripping down to bare cases before doing anything else. Once it's all apart on the bench you'll be able to identify what's salvageable, but the shopping list will inevitably include all the usual suspects (case repair and machining, crank & rods recon, barrel and pistons repair/replace, valves, guides and seats, chains, cams, rockers etc etc.....). Each part can then be assessed for re-use, re-con or replace with the benefit of a good clean, an expert eye and some measurement tools around them.

I would certainly advise against attempting to turn it over with this level of corrosion in the chambers. I've seen valve guides split and get pulled through on these engines from corrosion build-up on the lower part of an open stem locking out in the guide bore as the valve retracts after x years in the 'open' position. Short pics and vid of one such engine here: https://www.youtube.com/watch?v=d4EMFu5Jja0. In the vid, the bronze sleeve around the valve stem, that moving with the valve is not a good thing.

There's also the rapid increase in bore, ring and seat wear that will occur if the corrosion and piston crown deposits are allowed to circulate further around the chamber, or the further life expectancy of exposed bearing surfaces being asked to provide friction-free loadbearing after being left to dry out for x years......
Mike Champion
www.mceporsche.com
RobFrost
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Re: Assessing an unknown engine

Post by RobFrost »

jb wrote: Tue Mar 26, 2024 8:01 am The last one looks like a valve stuck on a piston
It is the valve, which is open. It's clearer on the video but there's clear space between the valve and piston. I was most concerned about the apparent black crack in the top of the piston.
1970 911T, Signal orange (Restoration thread)
1988 3.2 Carrera backdate, Black
2001 996 Turbo, Lapis blue (am I allowed to put that here?)
I'm looking for a pre-impact bumper 911S or other high-revving 911 to restore - please let me know if you see one.
RobFrost
DDK 1st, 2nd and 3rd for me!
Posts: 2035
Joined: Thu Jul 08, 2021 8:18 am
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Re: Assessing an unknown engine

Post by RobFrost »

MikeyC wrote: Tue Mar 26, 2024 11:31 am
Ultimately, Rob, I don't think there's any need to guess further on this one. The details shared so far show that the engine needs stripping down to bare cases before doing anything else.
Thanks Mike for confirming. I already have my copy of Dempsey in hand!
1970 911T, Signal orange (Restoration thread)
1988 3.2 Carrera backdate, Black
2001 996 Turbo, Lapis blue (am I allowed to put that here?)
I'm looking for a pre-impact bumper 911S or other high-revving 911 to restore - please let me know if you see one.
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