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Re building an engine

Posted: Sat Aug 17, 2019 5:28 pm
by Warsash 2
Hi
I have acquired a V8 engine that had been used by a technical college for student training. The engine number is 7K5617. I am assuming it is from a saloon but their does not appear to be kick down attachment on the cam case. The stamp marks on the pistons are all A except the front right hand one which is stamped B . The letters on the pistons seem to be randomly top and bottom in the bores I understood they should be at the bottom but i do not want to disturb the main bearings if it is no problem. There will no doubt be a lot of other things in the future. Any help would be appreciated. It is over 50 years since I rebuilt engine and then they were Bedford petrol lorry engines so I am very rusty.
Regards
Colin

Re: Re building an engine

Posted: Sat Aug 17, 2019 5:44 pm
by Vortex O'Plinth
Your engine is almost certainly from a saloon. Saloon engines were numbered with either a 7A or 7H prefix - are you sure yours reads 7K? A quick identifier is the oil filler tube; if it's short and straight it's an SP block, if it's long and 'S' shaped it's from a saloon.

If it has been used for student training I'd suggest you take nothing for granted - a complete strip-down and condition assessment would be very wise. The V8 is fundamentally a simple engine and rebuild should be straightforward. If you have any specific problems I'm sure there will be plenty of help here.

Re: Re building an engine

Posted: Sat Aug 17, 2019 6:17 pm
by classiclife
Hello Nick,

Can I just check the information you have provided please.

My understanding is that saloons have either a 7A or 7K engine prefix - the 2.5 V8 was 7A whereas the later V8-250 having the prefix of 7K.

The S shaped oil filler was used when the saloon was equipped with a single air filter element (2.5 V8) and the straight oil filler tube was used with saloons having twin air filters being the V8-250.

Colin's engine number appears to suggest a late 68 model or perhaps a very early 69.

I fully agree that any student demo engine needs to be fully stripped to ensure all is correct for obvious reasons.

Best wishes.

Richard.

Re: Re building an engine

Posted: Sat Aug 17, 2019 7:17 pm
by Vortex O'Plinth
classiclife wrote: Sat Aug 17, 2019 6:17 pm Hello Nick,

Can I just check the information you have provided please.

My understanding is that saloons have either a 7A or 7K engine prefix - the 2.5 V8 was 7A whereas the later V8-250 having the prefix of 7K.

The S shaped oil filler was used when the saloon was equipped with a single air filter element (2.5 V8) and the straight oil filler tube was used with saloons having twin air filters being the V8-250.

Colin's engine number appears to suggest a late 68 model or perhaps a very early 69.

I fully agree that any student demo engine needs to be fully stripped to end=sure all is correct for obvious reasons.

Best wishes.

Richard.
Thank you for the correction Richard. My reference for the saloon block numbering was Robert Grinter's write up comparing SP250 and saloon engines. Not having actually seen a saloon block myself, I'm sure your identification is correct. I'd forgotten that the V8-250 reverted to a straight oil filler tube, although still somewhat longer than that on the SP.

Re: Re building an engine

Posted: Sat Aug 17, 2019 9:27 pm
by classiclife
Hello Nick,

Phew !!!

Thought I had a SP engine in the saloon at one stage :o

Have to say although RG's article makes good reading, its layout can be confusing if not read over a couple of times to ensure clarity.

All the best.

Richard.

Re: Re building an engine

Posted: Mon Aug 19, 2019 11:36 am
by Warsash 2
Hi
Thanks for your advice. I had assumed it was a saloon engine but confirmation is a great help. As to the lettering on the pistons this appears to be some thing the college must have done. Looking at some old photographs it would appear that the larger, exhaust indentation should be at the bottom and I can disregard the lettering.
Thanks again
regards

Colin

Re: Re building an engine

Posted: Mon Aug 19, 2019 2:06 pm
by Ian Slade
As I understand it only standard bore can have A,B or C pistons whether they are at the top or anywhere else, however as your engine is ex college I would check the bore and remove at least one big end and main to check what you have in way of regrind or condition. Being ex college it will have been continually stripped and rebuilt therefore the bolts may well be overstretched

Re: Re building an engine

Posted: Wed Oct 09, 2019 9:32 pm
by chrismpw
Hello chaps - my first post here. Apologies if I dive into another's thread - but it is on the topic of engine rebuilds. First an introduction:

After working my way through a range of classic cars over the last 30 years or so; MG Midget bought in 1992 (I still have it), BGT, Scimitar GTE, Rover 3500s - this week I finally realised my dream and bought the number one car on my list - a Daimler V8 2.5 saloon. This was a car my dad had when I was between 7 and 14 and I was absolutely in love with it.

After searching high and low I finally selected one at trhe top end of what I could afford. Previously I'd always bought cars that needed work - I enjoy improving old cars and it was how I could afford my hobby. All of the cars were working cars and every day transport. After looking through a range of motors from - not working, to sound but with most of the trim missing and needing a repaint, I decided that this Daimler was to be special. The one I chose wasn't concourse - but wasn't far from it, a good history pointing to original low mileage, a good restoration done some years ago and the car clearly looked after.

Two days ago I bought it after a thorough inspection and a test drive. I was momentarily in heaven. This was to be the pinnacle of my motoring existence. It lasted 30 minutes.

On the journey home, the oil pressure started to drop. 20psi on idle, dipping below this on idle after a bit of exertion and only rising to around 30psi at a lick. THAT sound, I decided wasn't an exhaust note, it was a knock. Definitely a knock and it was only there on load. Big ends! How could I have missed that?

This morning I awoke with an enormous serving of buyer remorse. My budget is spent and there's nothing left for engineering. I'll admit I was quite miserable - until that is I looked out of the window, and there she was, smiling at me. She will rise, I decided.

So the reason for my post - what I would LIKE to do is throw a specialist a decent wedge of cash, leave them the car and have the engine done properly. As said though - the budget for that kind of thing has gone. 25 years ago an entire engine rebuild on my MG was less than £800. Today these prices are enormously exaggerated. Equally I don't want to entrust the engine to just anywhere.

The rest of the engine seems fine and she runs sweetly. My current thinking is to drop the sump and change the bearing shells in situ. I have some questions then for which i would gratefully receive opinions:

1. Has anybody done this?
2. Can anybody recommend or caution this route?
3. Can anybody suggest suppliers? (I'm aware of SNG Barratt and David Manners)
4. Would the shells be a standard size, or would I have to measure the specific diameter of the crankshaft (and hope its circular - how much non- circular is OK?). All this is with the hope that the crankshaft isn't scored or damaged of course.

Re: Re building an engine

Posted: Thu Oct 10, 2019 8:27 am
by daimlersteve
Could be the centre main cap broken

Re: Re building an engine

Posted: Thu Oct 10, 2019 8:41 am
by chrismpw
Daimlersteve .... the what now?