Cam Gear oiling

ian.stewart · Post by **ian.stewart** » Sat Aug 18, 2007 2:53 pm

finally I think I know why the engine broke, Not enough oiling to the cam sprocket, which has in turn caused excessive wear on the gear, and allowing the chain to climb a tooth on the bottom sprocket and breaking it.
I have been looking at Hardcastles book with a veiw to lubricating the gear from an extrenal source, the pic it shows is a feed from the bottom of the pump primary output to the top of the cam cover, Is this the beat place to remove pressure, or is the releif side of the pressure valve a better source, so I am not robbing pressure from the cam and crank, as I am running a solid lifters can i run a oilway restrictor in the valley oil ways as I dont need pressure to pump the lifters, only lubricate the bores

Discuss

Ian

kiwicar · Post by **kiwicar** » Sat Aug 18, 2007 4:09 pm

Hi Ian
the best option if you are going to use an extra oil feed would be to take oil from the relief side, as you say you want to preserve oil pressure to the mains. The only problem would seem to be, that as the pump wears and the bearing tolerences open you will get less flow on the cam gear feed but this is a spray to chuck oil in the vercinity of the cam gear, probably doesn't need more than a couple of cup fulls per minute and I would think you can get alot more than that.
Is there any way you could just direct the returning oil from the heads and the top of the block to return via the vercinity of the cam gear rather than all along the block? A few strategic bungs might do the job and less oil flying around the crank??
Mike

The Original Tom · Post by **The Original Tom** » Sat Aug 18, 2007 5:41 pm

Rob Heath posted some pics of his rebuild on here (or another forum) a while ago with a good remedy for this.
If you drill 2 small holes (4-5mm) at the bottom of each side of the valley, through the front of the block insode the timing cover, next to where the cam sprocket goes, then oil flowing down the valley will come out through here and fall onto the chain / cam nose and be distributed to the cam gear more effectively.

Seems a good idea to me and doesn't require any real plumbing. Worth a thought. HTH
Tom.

Post by **katanaman** » Sat Aug 18, 2007 5:49 pm

the oil pipe from the pump idea is really to lube the dizzy gears and not the chain. The two holes from the valley to the chain area gives better flow to the chain. You could still use the pipe but put it in a different place to the book. I have one of these around the garage somewhere and the outlet is very small so I don't think it will rob very much oil from the main system.

badger · Post by **badger** » Sat Aug 18, 2007 6:28 pm

Worth checking what dizzy gear you have fitted to the end of the cam as well. Early gears, as I discovered accidentally, have no oil relief passage machined in the back face, they are smooth on both sides. later gears (SD1 on?) have a small oil recess machined but more importantly are not flush across the surface. There is a small ammount of stand-off to allow oil flow out the rear face of the gear, from the keyway. The difference in oil pressure (between the 2 different gears, hot) on a good engine is about 3psi, but for peace of mind fit an MGB V8 relief valve spring which will take your system relief pressure from 30-odd to roughly 50psi.
Drilling the extra oil returns in the front face of the block is also a very good idea - I do all my engines this way, the holes being about 6mm. Just be careful of the oil gallerys.

mgbv8 · Post by **mgbv8** » Sat Aug 18, 2007 7:20 pm

Another option might be to drill a small hole in each of the oil gallery core plugs to squirt a jet of oil onto the back of the chain gear. I was advised to drill 0.5 to 1mm holes in mine for this purpose. I assume at 30-40 psi you will get a small jet of oil as required. I'll try this when I put the 3500 back together. It can only break eh?

ian.stewart · Post by **ian.stewart** » Sun Aug 19, 2007 4:44 am

The Original Tom wrote:Rob Heath posted some pics of his rebuild on here (or another forum) a while ago with a good remedy for this.
If you drill 2 small holes (4-5mm) at the bottom of each side of the valley, through the front of the block insode the timing cover, next to where the cam sprocket goes, then oil flowing down the valley will come out through here and fall onto the chain / cam nose and be distributed to the cam gear more effectively.

Seems a good idea to me and doesn't require any real plumbing. Worth a thought. HTH
Tom.

got the holes in the lifter valley, still got a dry chain

Perry The idea of removing one of the lifter gallery plugs did cross my mind and replace it with a screw plug wth a hole drilled thru it to squirtoil onto the back of the timing gear, and centrifugal froce would throw the oil outwards to the chain, how do you check it works??
I am leaning towards the pipe from the releif port on the pump, externally plumbed to the top of the timing case, and a screw in fitting in the top of the case directly above the chain, controling the flow could be choked down by using surgical needles silver soldered into the fitting, somthing like a 20 gauge needle should be more than adequate, or possibly use an old Bosch Ktronic? injector from a XR3 or diesel injector??

ihatesissycars · Post by **ihatesissycars** » Sun Aug 19, 2007 8:50 am

Getting rid of the dizzy drive gear altogether would be better with a serp front cover. You could adapt your present anciliary bits to suit it and then with some additonal oiling to the chain you should fix all your problems in one hit.

A set of coil packs and sexy serp eblt later you could have a bomb proof setup.

tapsak4 · Post by **tapsak4** » Sun Aug 19, 2007 12:27 pm

I remember seeing somewhere an external oil injector... the injected 3.9 was used in the Finnish "Sisu Nasu" all terrain military vehicle at some epoint. The engine was tipped towards the rear more than in Range Rover and the timing set suffered from oil starvation.

External plumbing and a small injector solved the problem.

What is the postition of your engine? Is it in the Cortina in you picture?

http://www.mil.fi/maavoimat/kalustoesittely/00098.dsp

Best regards from Finland,

Tapani

ian.stewart · Post by **ian.stewart** » Sun Aug 19, 2007 1:15 pm

I have Converted my dissy to run just the the pump, so when I come back I can go dissy less, Have you sold the Coilpacks??
Tapsak, Hi and welcome,
Thats very intresting about the Sisu Nisu, I walked past one in a scrap yard the other day, I know they were used by our Royal Marines with the Artic Cadre, I did not realise they were RV8 powered, Looks like I am back up the yard on my next day off, perhaps I may have some of the bits I need,
http://en.wikipedia.org/wiki/Sisu_Nasu

Yes that is my Cortina in the pic, sadly broken at the moment, but it will be back soon faster without gas, and running low 12s.
http://s168.photobucket.com/albums/u197 ... CF0039.jpg

Ian

tapsak4 · Post by **tapsak4** » Sun Aug 19, 2007 2:06 pm

The RV8 was used during some period of time. Also GM 6,2 and 6.5 diesel V8s and some other engines too. Dunno excatly what and when.

Tapani

mgbv8 · Post by **mgbv8** » Sun Aug 19, 2007 8:33 pm

I suppose you could run the pump on a battery drill while the front cover was off. That would work for a test wouldnt it?

mgbv8 · Post by **mgbv8** » Sun Aug 19, 2007 8:33 pm

Sorry
I'm being stupid. The pump is in the front cover, DOH!!!

ihatesissycars · Post by **ihatesissycars** » Sun Aug 19, 2007 8:50 pm

They've gone yes. I do have 2 spare ford ones that work, yours foc if you want them.

I got the Accel ones from summit, they also do some red MSD ones too.

http://store.summitracing.com/partdetai ... toview=sku

http://store.summitracing.com/partdetai ... toview=sku

Ian Anderson · Post by **Ian Anderson** » Sun Aug 19, 2007 9:10 pm

On the GT40 I have a J Eals motor

It has a braided hose that comes from the pump up to the base of the dizzy. If need be I can take pics and e mail as I am hopeless at posting on this forum!

Now if that works for the Dizzy - how about just taking that feed pipe and doing a T of it to spray oil elsewhere too?

Or have I just made it not enough oil for the bottom of the dizzy?

Ian