Square four mk1 frame

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FletchBurton
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Square four mk1 frame

Postby FletchBurton » Sat May 16, 2020 1:31 pm

Hi.
I am new to the club having just bought a mk1 square four.
I am just stopping the engine to clean the sludge traps and change the con rods. I have a set of new rods but the ones fitted look good/newish. See pic. So my question is should I run what I have or change the rods anyway?
Also what kind of money does a mk1 frame go for?
Thanks.
Fletch
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john.bebb
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Re: Square four mk1 frame

Postby john.bebb » Mon May 18, 2020 8:41 am

Hi Fletch,
Welcome to the severely retarded grumpy old farts community of nutters who endeavour to keep their Ariels on the road...!
So you've got yourself a Mk1 - financially - a potential bottomless pit - but persevere with it, learn / discover some of the innumerable idiosyncrasies of the beast & you may end up with a nice Brit. classic... do remember that it's >67yo and will never perform as a HondaYamaSuziKwaki nor a Beemer or Gutsy; - it will never handle well in comparison - the Anstey tail may have been state of the art when first produced (soley for maintaining constant chain tension (nowt else!)), it ain't a fully adjustable & electronically damped monoshock suspension... it will not stop like something with 3x 4 pot Brembo discs with antilock... so perhaps fit a Grimeca 4LS...
You will neither see where you're going, nor be seen by other road users at night - best option is to fit a 12V Iron Horse alternator & LED lighting... while you're at the electrics; - contactless points etc would not go amiss...
There's various other mods you can do to make it more appropiate to modern conditions but you still only has ~34bhp to play with...
Does it need new rods? - dunno! - do you know the full history of the motor??? - by far the most common problem with the Mk1 is it blows head gaskets - (so you should use Otto gaskets)... the second most common failure is piston seizure - this is NOT limited to the rear pots!
By cleaning the sludge traps you are doing the best preventative precaution to reduce the risk of seizure... fit a Morgo oil pump for further reduction of risk.. back to the rods - it's your choice - I'm not aware that throwing rods is a habit of Sq's - do a search on this site - I doubt there's many examples...
but maybes for peace of mind - fit a new set thus knowing they're of top quality in modern alloy... not ancient bits of postwar melted down scrap RR Merlins, Messerschmidts & B17s etc. full of casting inclusions & hairline cracks from ages of abuse...
What's a frame worth? sorry - dunno that one either; - whatever someone is willing to pay for it...
Oh well - maybes I ain't answered your questions too well, but a warm welcome to you.
Cheers, John
Last edited by john.bebb on Tue May 19, 2020 6:57 am, edited 1 time in total.

FletchBurton
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Re: Square four mk1 frame

Postby FletchBurton » Mon May 18, 2020 9:51 pm

Hi John,
Thanks for the warm welcome and words of wisdom. I was beginning to think I had offended the club on day one.
If I tell you I own several classic bikes including but not limited to of a pair of Panther M100 (rigid and swinging arm) and a Norton big four, 34 or so horsepower is going to be unbelievable, and as a Yorkshire man once said suspension, luxury.
I was asking about the rods because a few people have said sq's can throw rods through the cases but this seems to be due to big end seizure due to blocked oil ways. I will continue the engine strip when the puller from draganfly finally arrives, and check the traps. As you suggest I was going for Otto? head gaskets, I have bought the excellent Waller manual which has been a help so far.
The reason I asked about the frame is mine is more pissed than the father of the bride on wedding day and has been hacked about with, so I am trying to work out if finding another frame with all that entails or having this one sobered up is going to be the better option.
Cheers,
Fletch

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Re: Square four mk1 frame

Postby GuyWalton » Tue May 19, 2020 7:40 pm

For what it is worth I looked at my mk1 sq4 rods and decided to keep them couldnt see anything wrong with them and they too looked like new . Cleaned out the sludge traps fitted new shell and pistons ans all seems well .
51 mk1 Areil Square Four
55 DB 500 BSA Gold Star
55 Matchless G9
67 BSA B44
06 Ducati 999R

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simon.holyfield
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Re: Square four mk1 frame

Postby simon.holyfield » Wed May 20, 2020 9:06 am

Hi Fletch,

Welcome aboard. I too am using original rods. There is obviously a fatigue issue here, and none of us have enough knowledge of our specific engine to be able to estimate what the fatigue life of our specific rods may be, so I dare say we are all running a risk. Depending upon your access to non-destructive examination facilities, you could have someone do an ultrasonic inspection for cracks & flaws, or perhaps do a dye-penetrant inspection (maybe yourself) for cracks - but you might not find anything, and you'd still be potential prone to failure. However, fatigue failure is down to load, stiffness & cycles; you could argue (as I did, and I suspect Guy did) that you are not going racing and you are probably not going to add up a huge number of miles, and due to the light load & small cycles and that changing the rods is a cost too far.

From what I've seen, rod failures are derived from lubrication failure at the big end (often #3) and that is a result of the sludge traps blocking up.

My strategy is/was to clean my engine thoroughly, rebuild it carefully, fit a morgo pump and a filter and look after it.
cheers

Simes

'51 Square Four,
'58 Huntmaster,
'42 W/NG,
'78 CX500
http://ariel-square-four.blogspot.com

nevhunter
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Re: Square four mk1 frame

Postby nevhunter » Wed May 20, 2020 10:22 am

Alloy rods have a finite life. There's no real way of knowing what sort of treatment your machine has had but if the B/e Journals are standard size there's a fair chance it hasn't done a lot of KMS. These motors don't like or need high revs. That's for more modern stuff. You can do a crack test on the alloy rods but a very good inspection of the surface will probably pick any crack(s) as the finish is quite good.. Most blow ups were due to sludge and oil deprivation.. Nev

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rschurr
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Re: Square four mk1 frame

Postby rschurr » Wed May 20, 2020 6:45 pm

Definitely….

Alloy rods have a finite life…..

IMG_20200520_193558.jpg

IMG_20200520_193538.jpg


Cheerio Rudy
1923 James Model 12 500ccm v-twin -- 1960 Chevrolet Corvette C1
1926 Douglas EW 350ccm flat-twin -- 1967 Chevrolet Corvette C2
1936 Motosacoche 500ccm single --- 1979 Chevrolet Corvette C3
1948 BSA A7 500ccm parallel twin -- 1955 Ariel Square Four MKII :!:

david.anderson
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Re: Square four mk1 frame

Postby david.anderson » Thu May 21, 2020 12:08 am

Rudy
That is a very lucky find just in time.
It is also the same place where all the square 4 rods break. ( I have seen several broken 4 rods and have also discussed the matter with well known Arielist John Shanks who has seen dozens of broken rods, all as in the photo) The square 4 did have a reputation here for throwing rods, and while a lot of that is due to sludge trap blockage, there were many rods broken due to high revs. In Australia a very high percentage of square 4 crankcases have been welded up, including my own (ex-police 4). One reason for the high failure rate here was that a high percentage of 4s were used by various police forces. As any one knows the biggest hoons on our roads are the police, who regularly thrash their bikes or cars. I spoke to one former policeman who advised that he threw a rod on two separate 4s, and he admitted that it was at high revs on each occasion.
All alloy rods have a duty cycle. When that duty cycle is up, that’s it. And the problem is knowing just how much work the bike has done and whether it was thrashed. The aomcc rods solve that problem and are a superior rod to what was originally fitted and do not have the same weak spot shown in the photos. And as an encouragement there is a refund given when your old rods are returned. And the aomcc in its wisdom, then ensures the returned rods cannot be put back into service, ie they are destroyed. Well done aomcc
David

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Re: Square four mk1 frame

Postby john.whiting » Thu May 21, 2020 1:39 am

Allowing rods to whack against the edge of the case doesnt help either,and any marks on the rod should be carefully removed before a crack starts......If your rods test out as sound ,might be worth having them shot peened for a bit of cheap insurance.......I might add ,steel rods also break in service ,with similar results.

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rschurr
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Re: Square four mk1 frame

Postby rschurr » Thu May 21, 2020 8:14 am

" The aomcc rods solve that problem and are a superior rod to what was originally fitted and do not have the same weak spot shown in the photos. And as an encouragement there is a refund given when your old rods are returned. "

And so I did (after cleaning the sludge traps)!

Rudy
1923 James Model 12 500ccm v-twin -- 1960 Chevrolet Corvette C1
1926 Douglas EW 350ccm flat-twin -- 1967 Chevrolet Corvette C2
1936 Motosacoche 500ccm single --- 1979 Chevrolet Corvette C3
1948 BSA A7 500ccm parallel twin -- 1955 Ariel Square Four MKII :!:


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