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Engine now needs a rebuild

PostPosted: Wed Oct 04, 2017 10:25 am
by pauljones
Well ive decided i need the twink rebuilt after it sucked up all its oil and spat it out all over the place.

So with a standard bore 711m block thats covered low millage and a xflow crank,with some spare rods sat in the garage. Im considering passing these and my poorly twink to get rebuilt.

I guess im asking who are the go-too-guys now for full rebuild. I think im looking at the likes of Paul Exon, id rather keep closer to south coast if i can. Portsmouth being my base.

Any one got any ideas?

Re: Engine now needs a rebuild

PostPosted: Wed Oct 04, 2017 12:59 pm
by rjaxe
Sigma Engineering, Gillingham, Dorset. I have used them for crank etc balancing with no problems. Although they specialise in Jaguar engines they also have experience with Lotus twincam engines and have a comprehensive workshop. Might be worth giving them a call.

Re: Engine now needs a rebuild

PostPosted: Wed Oct 04, 2017 8:16 pm
by DavidLB
Paul exxon rebuilt mine and set it up on his dyno. 3 yrs ago no pros

Re: Engine now needs a rebuild

PostPosted: Thu Oct 05, 2017 9:39 am
by pauljones
Thanks for both points. Its probably an after xmas project due to costs. But ill look into both options.

Thanks

Re: Engine now needs a rebuild

PostPosted: Thu Oct 05, 2017 2:18 pm
by pauljones
Appologies for the blantant use of the picture, just seen in another thread.
This seems to be the area that most of my oil was coming out off, could i just have a blockage in breather system?

Re: Engine now needs a rebuild

PostPosted: Thu Oct 05, 2017 6:01 pm
by RichC
you said there was a metallic noise coming from back of engine ? worth checking your compression pressures IMO . although you might have a block, theres only a small stub of hose from engine to weber air box for it to be located. could it be knackered rings in number 4 cylinder providing excessive crankcase pressure ?

Re: Engine now needs a rebuild

PostPosted: Thu Oct 05, 2017 6:24 pm
by pauljones
Great point. Ill go buy a compression test kit.
Im also not running an airbox, k&N twin filters are fitted. I cant recall the oil breather fitment so ill need to check.

Thanks

Re: Engine now needs a rebuild

PostPosted: Fri Oct 06, 2017 8:19 pm
by pauljones
Had a chat with a couple of engineer firms today.

Cost to rebore the 711m block is ?150 and ?10 a journal. Im looking hard at keeping the twink running but with the bigger crank.
Static balance is not much but cant dynamic. I found a place that would dynamically balance for ?250.

I could have the bigger throw crank and re use my pistons if they're ok for about ?800 on a fully lightened and ballanced bottom end.

Does that sound resonable to those that are more in the know?

Re: Engine now needs a rebuild

PostPosted: Sat Oct 07, 2017 8:33 am
by jimj
Paul, I think you`re going about this the wrong way. You don`t want various people doing different elements of a rebuild where no-one would be responsible for the finished article.
You`d be better giving the engine, together with your crank and bits to one reputable company. Agree a price for a strip down, inspection and report, then make a decision. They may decide that using your different crank and stuff is a good idea, but maybe not and they`ll know better than you or me.
Don`t be hung up with finding a twincam specialist, it`s not rocket science (or so I`m told). Some years ago my engine started producing excessive smoke, bogged down then blew off the oil filter. I had the car recovered to this old, experienced bloke, now retired, that I used at the time. He rebuilt the engine and all has been fine.
A bit far for you but I currently go to Riverside Engineering in Whaley Bridge. He does work for School Garage and rebuilt an Elan engine for them a couple of years ago. More recently he rebuilt a TR4 engine for a pal and it`s never been better.
Conversely, last year another pal with an Elite sent his Coventry Climax to a, if not the, foremost specialist. I won`t say who as I`m not the customer but, suffice to say, if you were selling a car with such an engine it would be a strong selling point. Within 2000 miles the liners had slipped, he wouldn`t guarantee his work and charged my pal again to sort it. He didn`t return calls or answer emails, promised the car in January then Feb. then March, he finally got it back in June. It`s still not right even now.
So, I`d recommend you find someone locally, probably a one man operation, well experienced in old cars, a proper old style engineer and put your engine, and faith, in his hands.
Jim
P.S. In the overall scheme of things it`s not that expensive to have the whole car transported to the "right" man, even if it`s quite far.

Re: Engine now needs a rebuild

PostPosted: Sat Oct 07, 2017 9:00 am
by RichC
OK Paul. no airbox.... so what comes out from the back of the head behind the webers ? a breather pipe? or has it been blocked off?

Re: Engine now needs a rebuild

PostPosted: Sat Oct 07, 2017 9:03 am
by RichC
looking at that picture you have posted shows that the engine has had the rubber hose breather pipe lengthened and is running into an old oil bottle jammed beside the weber airbox. ... not a good look !...

Re: Engine now needs a rebuild

PostPosted: Sat Oct 07, 2017 10:09 am
by pauljones
Ok thanks Jim,

just to clarify a few things.

Bamba engineering in Portsmouth are the guys im looking at. They can only static balance but the use Saunders in Southampton for customers that want it Dynamically balanced. He said they would take it there but charge me accordingly or I could do the leg work my self. So im kind off keeping it under one roof. Just saving myself a ?50 an hour charge.
Theyre also less expensive by ?65 to bore up to 85mm.

Rich,

Honestly have no idea what's at the back. I need this weather to clear so I can look next week at any breather blockage issues.It may be a simple fix if its blocked.
Also that picture is not of mine, its one i borrowed from a simmilar post to use as an example.

So my jobs are to investigate and find cause, see if i can fix it.
If it needs a rebuild then im investigating the cost of a tall block bottom end.
If its all too much the engine will be sold and I use the cash to off set a zetec going in.
Its a shame because its a really strong engine and i love that sound. It is a bit lacking in bottom end, 3.54 diff shows this, and thats only reason im thinking of more cc.

All points gratefully recievied tho.

Paul

Re: Engine now needs a rebuild

PostPosted: Sat Oct 07, 2017 10:50 am
by john.p.clegg
Are Basset Down still going, they did an excellent job on my BSA many moons ago ?

John :wink:

Answering my own question a quick google gives....

https://bassetdownbalancing.com/

Re: Engine now needs a rebuild

PostPosted: Sat Oct 07, 2017 12:33 pm
by Craven
Check out these guys in Winchester, they provide a Two plane polar computer plot of their balancing work before and after.
This is the after plot of my crank, flywheel, clutch, and front pulley. Well, I was impressed anyway!!

http://www.ocservice.co.uk/
p1030267.jpg and

Re: Engine now needs a rebuild

PostPosted: Sat Oct 07, 2017 6:36 pm
by Donels
Rebuilding the bottom end is not complicated if you're familiar with engines. It's the twink cylinder head that requires the skills. The bottom end was designed for mass production and is fairly simple to put together.

A lot is talked about balancing and if you're racing balancing is a necessity but for normal road use where you spend little time at high revs it's not really required. If you do decide to balance then concentrate on the crank and flywheel as these are the bits that make a difference. The clutch may be changed and then the balance is different. The front pulley is small and only makes a slight difference. The rods are usually awfully unmatched and unless you moment weigh and balance them you're wasting your money balancing the rest. For road engines I never balance, for track engines I do.