Mallows & Archer Racer

davidd

davidd

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I ran across a photo of this a while ago but could not find a link to it. Bob Zwarts was kind enough to provide one as he knows the rig. With over head rockers and many mods it is quite a piece of work!

Mallows & Archer 2017 4.jpg


Here is the listing:

http://www.ebay.co.uk/itm/Vincent-c...e=STRK:MEBIDX:IT&_trksid=p2055119.m1438.l2649

David
 
greg brillus

greg brillus

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I can't for the life of me work out how you set the tappets on that engine..........??? For the price, it seems like pretty good value for money.
 
C

chankly bore

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davidd

davidd

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greg brillus said:
I can't for the life of me work out how you set the tappets on that engine..........??? For the price, it seems like pretty good value for money.
Click to expand...

Greg,

The oil line from the top of the timing chest feeds the rocker arm bearings, which are in the center of the rocker covers. The rocker covers come off exposing the rockers, which look like standard motorcycle rockers. Thus, the rockers have the usual screw adjustment on the push rod end.

Short of supercharging, this is about the only way to cram more mixture into the combustion chamber. I was talking with Stuart Hooper at Bonneville once when he mentioned he might go to .75" lift on the Velocette. I thought how lucky he was to have that option when I could barely get .5" with the Vincent. The Vincent design worked remarkably well at providing higher performance from standard components at the time. Today, it is easier now to get springs that won't float and push rods that don't bend forcing the Vincent hot rodders to do all sorts of elaborate mods to achieve maximum performance. It is nice to see that someone went to the trouble to test out the concept.

David
 
davidd

davidd

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Greg,

I should have added that you are probably correct that the engine has to be free of the much of the super structure to get at the rocker covers. It looks like the rockers are best adjusted when the engine is on the bench!

David
 
P

Phil Davies

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I have seen that engine on the bench, I can tell you there is more alloy as weld in it than was in the original complete engine castings.
Rumour has it that it was originally one of the ex Martin Davenport engines (as Dave M bought the original outfit and spares from Mart)
The primary side crankcase mouths have been expanded externally in order to move the cylinder stud holes, the inlet and exhaust ports look nothing like a Vin product, the entire ex port being re-angled.
The man that buyilt it for DM was a AMC G50 man, so he set about replicating as much of the G50 dimensions on to Vincent heads (personally I would have thought it would have been less trouble to cast new heads), the opportunity was also taken at the same time to bore and stroke it.
The crank is nothing like a Vin crank - its oval, yes really!
 
Len Matthews

Len Matthews

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Phil Davies said:
I have seen that engine on the bench, I can tell you there is more alloy as weld in it than was in the original complete engine castings.
Rumour has it that it was originally one of the ex Martin Davenport engines (as Dave M bought the original outfit and spares from Mart)
The primary side crankcase mouths have been expanded externally in order to move the cylinder stud holes, the inlet and exhaust ports look nothing like a Vin product, the entire ex port being re-angled.
The man that buyilt it for DM was a AMC G50 man, so he set about replicating as much of the G50 dimensions on to Vincent heads (personally I would have thought it would have been less trouble to cast new heads), the opportunity was also taken at the same time to bore and stroke it.
The crank is nothing like a Vin crank - its oval, yes really!
Click to expand...
Talking to Dave in the Cadwell paddock ages ago, he was scathing about standard Vincent components which I thought was a bit unfair considering what has been achieved using them. BTW, Phil, are you still in touch with Martin Davenport - if so, send him my greetings.
 
P

Phil Davies

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Len Matthews said:
Talking to Dave in the Cadwell paddock ages ago, he was scathing about standard Vincent components which I thought was a bit unfair considering what has been achieved using them. BTW, Phil, are you still in touch with Martin Davenport - if so, send him my greetings.
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Hello Len,
Long time no speak, only about 35 years!

Dave was scathing about everything - when he bought Martin's Pete Russell chassis outfit he reckoned it was lousy and didn't handle, fact is he couldn't drive it - his racing experience was solely from grass outfits, he expected road race outfits to handle the same, so when they didn't he built one that did! I pity anyone that tries to race that outfit as it will be very 'twitchy' to steer, because that is what Dave thought they should be.
The problem with Dave's engine builder was that all he ever actually wanted was actually a G50 based v twin, someone obviously didn't tell him the vins don't seem to have 99.9% of the components or dimensions of one!
The cams in the beast are reputed to be based on Honda F1 engine events with roller followers.
I am still to this day trying to understand how a (now declared) 1360cc engine was able to compete in a 'up to 1300cc event, I even remember rumours about 1400+cc

I am still in touch with Martin, all be it not very frequently at all, last time I saw hime he was still the same jolly character - his sons are now charioteering with a homebuilt (what else with Martin about) 125 Aprillia engined kneeler outfit at BHR meetings. They are a chip off the old block for driving ability as well (no surprise there then!).
 
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