Engine rebuild

Technical MGB discussion
Hazza1190
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Forename: Harry
Surname: Bukin
Location: Devon

Engine rebuild

Post by Hazza1190 » Fri Feb 14, 2020 1:50 pm

Hi Guys,

Just wondering what you think of the prices i have been given to have the machining done on my engine. I am rebuilding it myself but obviously need the machining done by a specialist. I am getting it done by a local shop that has very good recommendations and it highly regarded.

- Lighten and skim flywheel - approximately £80.
- Afterwards the flywheel and crank will need to be balanced which involves the following:
Crank ground/polished/oilways cleaned as required
Timing sprocket/front pulley/harmonic damper and fasteners which will be used
Flywheel bolts, new clutch basket, spigot bearings and fasteners
(After balancing none of these components can be changed on assembly)
Cost, approximately £130
- Rebore is £120, we do require the pistons to hone to size, but we can supply them if needs be.
- Resurface block - £50.
- + Small amount of labour for cleaning/fitting etc.

I have never had this kind of work done before so no idea what prices i should expect. What do you guys think?

Cheers!
Harry.
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Peter Cresswell
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Re: Engine rebuild

Post by Peter Cresswell » Fri Feb 14, 2020 9:35 pm

Hi Harry,
The prices you have quoted seem to me to be in line that a machine shop would charge for basic work to recondition an MGB engine and you do all the fettling and assembly work.
I have recently rebuilt my own engine, but have also modified considerably so the machining work and the parts were around £2,500.

Added to your list, you should really fit a new clutch - a 3 part Borg and Beck kit is best which is around £90. This needs to supplied to the machine shop for balancing along with the flywheel, crank, front sprocket and pulley. The camshaft needs careful checking for wear and a replacement needs new cam followers - a new replacement is around £150 + £40 or so for followers, and a chain is around £30 for a good quality one. A worn cam will deprive you of the benefits of a reconditioned engine. The rockers need checking for wear as does the rocker shaft - if worn add £120. If they are going to rebore the block you will need a new set of piston - with rings and gudgeon pins cost around £150, and the big end bearing and main bearing plus thrust washers £65. A oil pump is around £40; gaskets about £60. I would add £100 for miscellaneous items such as studs, bolts, washers and nuts.
So you can see that once you start looking carefully, the costs start to escalate quickly.
Having the flywheel lightened is a good idea and makes the car much livelier. The standard flywheel is quite heavy at 21.4lb. The B&G lightweight flywheel is only 11.6lb (I've weighed them!) and the effect is the car 'appears' to be over 1cwt lighter to the engine, which means it accelerates a fair bit quicker. I've not noticed any detrimental effect using this flywheel other than the tickover is around 800rpm. Just taking off a few pounds rather stunts the effect of flywheel lightening.
You haven't got checking the cylinder head on the list. Check it isn't cracked and if it needs converting for unleaded fuel. It will also need skimming if the block has been done.
I would mention that it is worth having the block acid dipped as this gets rid of all the sediment that accumulate within it and gives a nice clean and dry surface for a nice new coat of paint - MG Maroon or black depending on the year of the car.
Although this sounds as though it gets expensive remember a damaged ford three cylinder engine without ancillaries is around £5,000, so an MGB engine is still relatively cheap.
Building it yourself is very satisfying - even therapeutic!
Pete
1969 MGB Roadster
2011 MG 6 TSE Magnette
2007 Mercedes SLK
Plus 32 other cars since 1965
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Paul Hollingworth
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Re: Engine rebuild

Post by Paul Hollingworth » Sat Feb 15, 2020 1:16 pm

I've just looked out my bill from my engine rebuild done in 2018. The machining was done by MJA Automotive in Bromsgrove. My feeling is that they are proficient and their facilities are impressive. Some costs I can breakout are :-
Re bore to plus 0.040" £100
Face block £35
Unspecified head work £120 - presumably re-facing of seats, valves and head face maybe some gas flow work, but it was already Burgess Econotune.
Other significant parts (mostly from David Manners) :-
Rings £65 from Federal Mogul (we had salvaged pistons from another engine)
Rear crankshaft seal £17
Head Gasket set £26 (Payen)
Bottom end gaskets £9
Clutch kit £66 (Borg & Beck)
Bearing shells, mains & BE £32 (crank didn't require re-grind)
Cam followers £8 (camshaft was OK)
Timing Chain and tensioner £ 8 (pulleys changed previously)

Some of these prices may have been trade but MGCC members get discount. So you can see that spending soon mounts up and there were lot of parts that didn't require changing having already been done 35000 miles before. Oil pump rotors for example.
1971 MGB roadster & 2006 MGTF
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Peter Cresswell
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Location: Stone, Staffordshire

Re: Engine rebuild

Post by Peter Cresswell » Sat Feb 15, 2020 10:13 pm

Paul and Harry
I've based most of my prices on those in the Moss catalogue I picked up at Stoneleigh last Sunday, and I must admit I am a bit surprised by how much some prices have risen in recent times.
Moss products are generally very high quality and their prices reflect this, so consider the prices in my post as the most you should pay. Many machine shops will be able to get engine components (pistons, rings, bearing etc.) at a better price, and as ever it does pay to check prices from several MGB parts suppliers before placing an order. Make sure you are comparing like with like though. Aftermarket part numbers have a 'Z' suffix and can be of varying quality and life compared to OEM parts without the suffix.
Pete
1969 MGB Roadster
2011 MG 6 TSE Magnette
2007 Mercedes SLK
Plus 32 other cars since 1965
Ian Fozzard
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Re: Engine rebuild

Post by Ian Fozzard » Sun Feb 16, 2020 8:09 am

As a minor afterthought to this discussion, I would support Peter's last point about component quality. In my opinion the quality of the original MG components is very high - good material used, and many aftermarket components do not meet this standard.

I have always re-used B series valves on my engines, probably sacrificing some performance but saving lots of cash. I did spend on pistons though, my local engineering shops do not value some of the lower priced pistons, the dimensions apparently are a little inconsistent!

So I would think it is always worth buying good quality and paying the extra if you cannot reuse an original component. After all, you don't want to be rebuilding again due to some component failure.

Ian F
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Paul Hollingworth
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Re: Engine rebuild

Post by Paul Hollingworth » Sun Feb 16, 2020 10:58 am

I wouldn't disagree with about buying quality parts. Of course a vast array of these are available from India as the Ambassador (Morris Oxford) has only just gone out of production. I have their camshaft and timing sprockets. I have County brand shells made in Israel and I'm pretty sure they are Aluminium-Tin which is plenty good enough for our engines. I used to have genuine Leyland (A series type) cam followers but the engine builder changed them although there was nothing wrong with the old ones. (I'm guessing he didn't keep them in order) The replacement ones are probably made by the same people anyway (Lydmet?) If I have any wear issues I'll put old ones back in. My rings didn't come from Manners they are Glyco/Nural and I got my AE pistons from a slightly used Ivor Searle engine that had been left out in the elements (the owner chose to bore to + 0.060"). Of course my valves, guides and seats are from Peter Burgess.
1971 MGB roadster & 2006 MGTF
Hazza1190
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Forename: Harry
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Location: Devon

Re: Engine rebuild

Post by Hazza1190 » Mon Feb 17, 2020 12:06 am

Thanks for the replies!

Luckily I found a brand new 3 part Borg and Beck kit on eBay for £12 so that was my bargain the other week. The current cam shaft looks to be in perfect condition, however I am going top get a piper 270 cam along with a peter Burgess Ecotune head.
I will definitely need new followers and push rods as the ones on mine look very worn (see image). The follower faces are in perfect condition so i am a bit confused why that have all worn in the exact same way (they all look the same).
My current engine has a single timing chain and not the duplex. Should i upgrade to the duplex kit?
The reason that i'm getting it lightened is because it needs resurfacing due to a previous owner running it down to the rivets and scoring the face, and it wasn't much more expensive to lighten it at the same time.
I am going to check the clearances on the oil pump then will decide whether it needs replacing.
I expect ill be going +20 thou over so i will find some pistons, however, i'm guessing i will need to get them to fit them as they are the press fit type?
I will ask about getting it acid dipped.

Cheers all!
Harry
Attachments
pushrod.jpg
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Paul Hollingworth
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Re: Engine rebuild

Post by Paul Hollingworth » Mon Feb 17, 2020 10:15 am

My friends say that County brand pistons look good and are an exact replica of the AE ones. They are running with them with no problems. Does anybody else have experience with them ? Yes you need to either hire a tool or get someone with a press to push your gudeon pin through the little end eye. I'd expect who ever is doing your re-bore to be able to do that for you.
Speak to Peter he has strong views on which camshaft you should fit and also you may need different valve springs if you increase lift. It would be good to ask him about the duplex chain also. I think the parts are interchangeable.
1971 MGB roadster & 2006 MGTF
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Peter Cresswell
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Re: Engine rebuild

Post by Peter Cresswell » Mon Feb 17, 2020 10:25 pm

Hi Harry,
You always need new followers with a new cam, and when you fit the cam and followers you need to very carefully follow the Piper (or Kent) instructions regarding lubrication and running in instructions. Piper can supply sachets of cam lube and you need to make sure when you first start up the engine that it starts immediately and you run the engine at a constant 2000 - 2700 rpm for at least 20 minutes. This is essential for the life span of the camshaft. If you need new pushrods be aware there are 2 lengths and each of these has different followers, so make sure you get compatible ones. The longer pushrods have a shorter cam follower and I think these are used in the later 18V engines. Some people say these are better anyway as the cam follower is lighter and the longer pushrod makes for better geometry over the earlier ones. As a set they are interchangable with the early ones.
Peter Burgess reckons the single chain is ok for road use, and I suspect his recommendation for the cam would be a standard one, but from Piper and ground onto a blank. The Piper cam kits come with suitable followers and valve springs.
If you haven't got it Peter Burgess' book 'How to Power Tune MGB 4 Cylinder Engines for Road and Track', is highly recommended and tells you all the ins and outs of the MGB B-series engine. A new edition has been recently published and he has updated his knowledge.
Pete
1969 MGB Roadster
2011 MG 6 TSE Magnette
2007 Mercedes SLK
Plus 32 other cars since 1965
Hazza1190
Posts: 37
Joined: Mon Jun 25, 2018 2:04 pm
Forename: Harry
Surname: Bukin
Location: Devon

Re: Engine rebuild

Post by Hazza1190 » Tue Feb 18, 2020 11:33 am

Hi Peter,

Thanks again for the reply.
Sorry yes you're right, ill need cam followers regardless. Did you see the picture of the wear that I attached? Each pushrod is worn in the same way, its an odd wear pattern is it not?
Yeah i have read about running the engine at 2000+ revs for at-least 20 minutes so will definitely make sure that its done.
As ill be replacing the sprockets and chain anyway, it makes sense to move to a duplex setup so i'll do that regardless. the kit's seem to cost about £40 which isn't too bad.
I have Peter Burgess' new book, in which he does recommend (or praises) the Piper 270 cam so i think ill go with it. I believe Peter Burgess can supply them. I have sent him an email so will wait for his response.

Cheers,
Harry.
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