Re built engine check over

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Zaphod
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Re built engine check over

Post by Zaphod »

Hi, I have recently purchased a kit of Excel parts, a complete car in fact. The previous owner has rebuilt the engine over the past two years but it has not been installed or run, I plan to do a compression check on it and fit it with an oil pressure gauge and see what pressure it reaches while being cranked over on the starter out of the car prior to fitting it. What other car KS should be made prior to putting it back in?
Of all the things I have lost I think I miss my mind the most...

1952 MG TD
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Alan_M
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Re: Re built engine check over

Post by Alan_M »

Don’t think you’ll get much if any oil pressure just cranking in the starter.

What checks to do I guess depend on how much confidence you have in the person who built the engine. But as it’s an interference engine I would at least check cam timing, valve clearances and everything is torqued up correctly. If not much confidence then drop sump and check crank and bearings for condition and clearances.

Zaphod
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Re: Re built engine check over

Post by Zaphod »

I did on my MGs, and the sprite, crank them long enough and they would build upto full cold oil pressure!

The safest policy is full paranoia.. The engine had had new pistons, rings and liners, it’s also had the crank reground and new cams
Of all the things I have lost I think I miss my mind the most...

1952 MG TD
1957 MGA 1500
1959 Austin Healey Sprite
1975 MG Midget 1500
1990 Lotus Excel

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MetBlue
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Re: Re built engine check over

Post by MetBlue »

With that much spent on the components, if you don't have receipt of a recognised firm rebuild, I'd at least drop the sump and lift the covers and check valve clearances. I'd then go further if I didn't see anything less than 100 % quality work.

Tony
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bash
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Re: Re built engine check over

Post by bash »

Compared to a big engine problem the cost of a full gasket set is minimal. I would strip the engine and check everything.
Bash
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Lotus-e-Clan
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Re: Re built engine check over

Post by Lotus-e-Clan »

I feel your concern. If it has not run since rebuild then it's an unproven engine which is almost as stressful as a broken one, until it's ran! :(

I've built a few engines in my time and I'm always concerned about something I might have not done so well and wouldn't be happy until it had run fault free for the first few miles, and then again not fully happy until I'd properly red-lined it.

If you were the builder then you might have half an idea what you might be worried about on first starting. Otherwise it's a leap of faith unless you strip and rebuild it yourself ... worth the gastket expense as Bash wisely suggests.

Agree with others on cranking oil pressure. Mine's a good original factory built engine and in 20 years running I've never seen oil pressure on cranking no matter how long it's cranked. Partly because the pump is so high above the sump, and the anti-drain oil filter acting as a resistor, is high up too, pressure doesn't build until the revs are north of 600 rpm for a few seconds ..not easy to exceed 600 rpm with a starter even with the plugs out.
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DavidOliver
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Re: Re built engine check over

Post by DavidOliver »

Starter cranking is too slow and an engine not run for some time will probably have lost bearing lubrication.
A very good reason for dropping the sump and inspecting bearings, you can see new lining condition. Use Cam lube (Kent cams) to refit the bearings.
You might decide not to lift the crank bearings, if so pressurise through the oil gauge take off and hand spin the crank, (head off).
These days you can get cheap endoscopes to have a look at the top end without dismantling the head, valve cleanliness etc.
A sign of workmanship can simply be looking at crank seal carrier plates and jointing compound, cleanliness.
To check oil pressure without load you can set the crank at 90º, remove the timing belt (a new one is good anti paranoia medecine) and with an electric drill spin the auxiliary pulley to spin the oil pump. It takes a surprising time to get pressure but will eventually show up on the gauge.

Dave the cog.

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Re: Re built engine check over

Post by Pete Boole »

bash wrote:
Mon Aug 30, 2021 03:35
Compared to a big engine problem the cost of a full gasket set is minimal. I would strip the engine and check everything.
Bash
Me too. It's only a few days work - not much in the scheme of re-commissioning the car.

Pete

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