Cross Drilled Cams

[OhcMk1]

I have a Xdrilled camshaft with the markings 43K at the back anyone has any any wat the specs of it maybe(will post some pics tomor of it)

Whats the reason behind the x drilled cams though? Wasn't the oil spray bar sufficent?

[Travis Peacey]

Iv'e heard the spray bars can clog and bugger up your cam

[Neville Bertwistle]

The spray bars also have a nasty habit of breaking as well as clogging up. Either way when the oil flow stops you are not going to know until you hear the ticking of a worn cam lobe. By then its new cam and rockers time.

The cross drilled cam overcomes that problem improving reliability.

[gen mk 1rs2000]

[Brad M]

[gen mk 1rs2000]

[OhcMk1]

[Danny M]

[Miniliteman]

[shaunb]

I suppose its horses for courses...

All the Group C racers and Aussie rally cars (Group G etc) ran spray bars...

My 2 litre has been together 15 years now. It has been pulled down twice for a checkover and new bearings when required.

It has done countless club rallys, classic bitumen rallies and khanacross's etc and is still going strong....damn unreliable spray bars....

Cheers

Shaun B

[Danny M]

[OhcMk1]

[Miniliteman]

[OhcMk1]

so its the GP1 cam listed here?

[Miniliteman]

[OhcMk1]

[Miniliteman]

All depends on how you drive really.
A Club Member once had a 2 litre with an RL2 cam (312 degrees, 96 degrees overlap) and thought it was brilliant for the road (with a std. carb).
I had a P284T cam long time ago in my RS2 and remember it as too peaky; the WR40 in the list is sort of the same spec.
To get that cam more tractable you would need a flowed head and raised C.R.

Regards, Leon.

[Roger Miller]

re Cross drilled cams...................

Some form of reliable oiling is necessary.

I doubt, that oil @ one revolution per cam rotation [eg oil in cam] is as good as all the time [ eg from external source].

The external system has its faults, but nothing is for ever.

I have been using external system for a number of years now, without failure.
I have a ritual, whereby I take rocker cover off and have a look after each outing.

I note that the Datsun L series engines have the oil flowing thru cam and depositing onto lifter, as a std thing.

It is note worthy, that when they setup for race applications, they add an external, spray bar system.

[Craig]

why can't you make a new spray bay that bolts up to the existing holes but comes over the cam and sprays directly onto the wiped surfaces of the rockers.

I thought the biggest problem with a spray bar is that it doesn't spray into the optimal place. As far as blocking up goes, a competition or fast road motor should be getting it's oil changed often enough for the blocking up issue not to be a problem.

Also a re designed spray bay lets you use different cams in the one head without getting them all crossdrilled, or using the spray bay on differnt heads.

Craig

[Danny M]