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Speedy engine upgrade - Mark Dymond - 06-08-2021
I'm slowly getting around to pulling out the "speedy" engine from my Arrow to investigate the cause of its low oil pressure. The engine, apart from pistons and con rods, is as it left the factory. Forum members with more experience than me have recommended the camshaft should be replaced - so it makes sense to do this as well as giving the engine an all over check for problems.
I can buy a reground "normal" camshaft from the UK (I'm in Australia) but this would necessitate bushing the center bearing, new front bush and a new cam gear, doable but not ideal. Is there another option, has anyone had a new camshaft made to suit, especially in Aus or modified the sports cam to lessen its aggressive profile. I know of a company in Queensland that makes billet camshafts but without a specification I would be lost.
Also, is it recommended to do the oil pump capacity upgrade or any other mods when I have the engine out?
RE: Speedy engine upgrade - Ruairidh Dunford - 06-08-2021
Paul Bonewell can make you a new camshaft he can be emailed on: paulbonewell@btinternet.com
RE: Speedy engine upgrade - Mark Dymond - 06-08-2021
Thanks Ruairidh, yes I have contacted Paul and he has been very helpful and is most probably the way I will go. This will however require the modifications I have noted above so i feel its worth exploring alternatives.
RE: Speedy engine upgrade - JonE - 06-08-2021
So from your exchanges, it's impossible to alter an existing one without compromising the result one is after? Or is just that those associated areas would also need to be restored anyway?
RE: Speedy engine upgrade - Tony Betts - 06-08-2021
hi mark,
dont give up on your original cam easily.
yes its a good idea to have a bonewell cam just in case.
i run an original ulster engine in my supersports, and yes it can be a bit high. but you learn how to use the engine as it was made for.
be careful of some info that people give, as it can be more from hearsay, than first hand experience.
personally, and this is just my experience. build the car to its original spec. drive it for a good length of time and see what you think. then give it a the same length of time again driving it, to see how you get on driving it as it was made. if you are not happy. thats the point you should look at making changes.
but i think at that stage, you will probably be able to live with it as an original car.
tony
RE: Speedy engine upgrade - Colin Reed - 06-08-2021
Hi Mark,
If you send the Camshaft to the firm in Queensland they will be able to replicate regarding the bearing journals.
That just leaves the cam profiles a standard profile is
Base Circle .750 th
tip radius inlets .125 th
Exhaust .187 th
lift on both .240 th
Timing will stay same as the camshaft you send
there is no practical way to reprofile the existing cam apart from welding and a regrind not worth it.
Hope that is of some Help
Colin
NZ
RE: Speedy engine upgrade - Mark Dymond - 07-08-2021
Hi Tony
Good to know you are also running with the original insides. My car does drive nicely with the original cam, which is one of the reasons I'm reluctant to change it. Id feel a bit of bit of twit though if I did nothing and a crack developed in the crankcase. I must be getting old, I would never have taken the cautious approach 30 years ago!
RE: Speedy engine upgrade - Chris Garner - 07-08-2021
Mark,
I run my 65 on a completely standard engine with original crank and rods. I'm careful with it, warming the oil up, never using high revs and not labouring it in high gears at low speeds. Coupled with an original gearbox and CWP it is a joy to drive as well as being able to keep up with traffic, not being too much of a hinderance as a standard Seven can be at times
RE: Speedy engine upgrade - Tony Griffiths - 07-08-2021
When a crank breaks it appears to be the luck of the Devil what happens. When I broke one at maximum rpm, the damage was limited to a crack in the crankcase wall. Decades ago, a friend's Nippy - with an original engine in apparently good order - let go at a modest speed and smashed everything to bits - only the peripheral parts, the cylinder head and a few fittings were salvageable.
RE: Speedy engine upgrade - Tony Betts - 07-08-2021
Tony,
I've had similar.
My first ulster I made, when I sold it the new owner drove it like he stole it. Broke the crank.
The damage was to the white metal on number 4, the number 4 piston, and obviously the crank.
Were as I had a customer bring his engine in, and it looked like someone had dropped a handgranade in the engine.
The engine was in around 8 large pieces, but that's not all.
It broke the bell housing on the gearbox, wich had to be rebuilt. And it threw the fan blade into the radiator, so the rad had to be re-cored.
I think what may have been put in Mark's mind, is the extra force from the high lift cam, may force the smiley face cracks that form on the side of the crankcase.
If so, I feel that damage comes from double springs? And most likely the block nuts not being tightend properly.
I've never seen an original 1 1/2 crank brake, but I have seen one that has formed the usual crack in number 4 jernal. So you are unlikely to brake the 1 1/2 crank.
But for me the ulster engine isn't cheap, and almost impossible to replace. So it runs with a Phoenix.
(for those 2ho put there sports engine under the bench, because they are afraid of breaking it?) Who are you saving it for, the mice.
Tony.