Author Topic: A10 new restoration, Engine  (Read 5347 times)

Offline polly

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A10 new restoration, Engine
« on: 07.04. 2016 17:09 »
this is the arrangement on this bike

Online RichardL

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Re: Re: A10 new restoration, Engine
« Reply #1 on: 07.04. 2016 17:51 »
....
And the problematic matter: What is the state of the crank sludge trap ?
....
The crank sludge trap and crank oil way in the timing side beeing the two huge weak issues.
Get them checked and sorted, can save disaster...

Smart advice from Viking. I wish I had said it myself because it points to my own first big A10 rebuild cock-up. In 2005,  I completed my first A10 engine rebuild after my bike sat for 25 years.  I followed the Haynes manual rather carefully. Problem is, as far as I have seen, the Haynes manual never mentions or shows the sludge trap, so I didn't know about it and, therefore, did not clean it. About 20 miles into test rides I spun a big-end bearing with the best explanation being that stuff from the sludge trap blocked the oil hole.

Richard L.
Plan on signing up for the world-wide 2017 DISTINGUISHED GENTLEMAN'S RIDE on September 30, 2018. Watch website at https://www.gentlemansride.com for details.

Offline polly

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Re: Re: A10 new restoration, Engine
« Reply #2 on: 07.04. 2016 18:10 »
indeed smart advice I hadnt thought of ..

Thats why Im glad I found you guys

Offline polly

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Re: Re: A10 new restoration, Engine
« Reply #3 on: 07.04. 2016 21:47 »
The machine shop has told me the barrels needed a light hone and the pistons are ok and will work in those bores...So I have ordered a set of hasting rings to suit the piston size.

So the source of the smoke must be a valve guide  so Im sending the head to them next...I may decide to fully strip the motor in light of what I have now learned on this forum however  . 

 

Online KiwiGF

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Re: Re: A10 new restoration, Engine
« Reply #4 on: 08.04. 2016 11:31 »
Well the head steady looks fine.

The machine shop, they say the barrel on the bike is ok? If so I wonder if worn guides could cause the level of smoke you are seeing? They would have to be very bad to cause a lot of smoke ( in my opinion).

My guess is the decision on whether you strip the engine completely or just the top end should depend on whether the bike has been run much recently, if it's been run a fair bit recently I personally would leave the complete strip down to later and just enjoy the bike until it's off the road anyway e.g winter.

However, the general belief seems to be that you should not put a high detergent oil in a bike that may have grunge in the sludge trap as the detergent could flush the grunge out and through the big ends  *help* *problem* so an oil change may be be a good option to take straight away so you know what's in it.
New Zealand

1956 A10 Golden Flash EA7-168x, CA10 913x, left BSA together for Liverpool, 5th Dec 1955.

1949 B31 rigid “400cc hot rod” (favourite bike)

1949 C11 rigid, but why!!! (cos it was cheap)

1937 B21, missing parts so mission impossible?

1952 Armstrong Siddeley Whitley for rainy days (with wife).

GL1800 Goldwing not sure why, maybe cos it always starts

Offline polly

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Re: Re: A10 new restoration, Engine
« Reply #5 on: 08.04. 2016 15:00 »
Yes ,
I will await the evaluation of the head before deciding..For sure a complete overhaul would mean not being on the road this year.

I was told it ran for a few extended outings last year but was laid up to investigate the smoking . 

Offline polly

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Re: Re: A10 new restoration, Engine
« Reply #6 on: 08.04. 2016 15:02 »
I was also told it went like a scalded cat   .but then a seller may well say that.

If not for another project the guy had that I saw he wouldnt of sold it for sure.

Online RichardL

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Re: Re: A10 new restoration, Engine
« Reply #7 on: 08.04. 2016 15:23 »
I like Kiwi's wisdom, also. A year ago is not a long time, and it did start up, apparently without much trouble  (albeit with smoke). 25 years, as in my case, is a long time.

Richard L.
Plan on signing up for the world-wide 2017 DISTINGUISHED GENTLEMAN'S RIDE on September 30, 2018. Watch website at https://www.gentlemansride.com for details.

Offline polly

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Re: Re: A10 new restoration, Engine
« Reply #8 on: 09.04. 2016 13:12 »
As far as the head goes and depending on what the machine shop reports back [Im expecting a valve guides replacement ] Do I stay standard or go for the valve seat update so it can run on unleaded fuel ..?

Anyone here done this update and if so what were the results .

Online Klaus

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Re: Re: A10 new restoration, Engine
« Reply #9 on: 09.04. 2016 13:38 »
As far as the head goes and depending on what the machine shop reports back [Im expecting a valve guides replacement ] Do I stay standard or go for the valve seat update so it can run on unleaded fuel ..?

Anyone here done this update and if so what were the results .


Hi Polly,

have a look at the head castnumber. If its 67-1549 or 67- 1571 there are big valve heads.
I recomment colsibro valve guides fom SRM and also the valves.They have also a bigger inlet with 1 1/2 " (38,1mm) in stock.

I do run serval A10, also at the racetrack, there is no need to change valveseats to run unleaded fuel. You can save this money.

Cheers Klaus


If you think, everything is under control, you are not fast enought.

Offline jachenbach

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Re: Re: A10 new restoration, Engine
« Reply #10 on: 09.04. 2016 13:59 »
Very nice project! You've found the right place for lots of great help. This forum is by far the best resource I've found on the internet.

Offline polly

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Re: Re: A10 new restoration, Engine
« Reply #11 on: 16.04. 2016 20:29 »
bottom end done   

Offline polly

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Re: Re: A10 new restoration, Engine
« Reply #12 on: 17.04. 2016 14:46 »
So I was going to drop the head off tomorrow at the machine shop so I looked for the casting number = 67-1126 so no luck of it being a big valve head but then to my dismay I noticed a crack ...Im not sure if that can be repaired or not. If its not Im in the market for a head.

Online Greybeard

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Re: Re: A10 new restoration, Engine
« Reply #13 on: 17.04. 2016 14:50 »
That is a right dratsab!  *cry* Things were going so well!

Offline polly

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Re: Re: A10 new restoration, Engine
« Reply #14 on: 17.04. 2016 15:40 »
Indeed Greybeard a real bummer.

An engineer from work just had a look and says thats a bad place for a crack and also pointed out that it looks like the pushrod holes seem to of been enlarged to the point that the head gasket only just covers....I have nothing to compare it with of course.

I do have a bare iron head maybe for this season thats the way im going to have to  go, but again I have no idea whats involved with that swap.