Cam Timing

[Duane]

Hi Team,

I have purchased a new cam kit from Wins International and have a couple of questions because the car still can like a pig after installing it. I have ended up pulling it all apart again (including the pistons which 3 off have broken top compression rings). Another order from the UK required.

1. The attached pics show the cam sprocket supplied. It has a "mark" on each side which could be the timing mark. Has anyone bought one of these and can tell me which is the right one to line up with the crank sprocket dot. I assume it is the one on the circumference as that lines up the same as the diagram in the manual.

2. What would be causing some of the new hydraulic lifters to be spongy. The odd bank are all nice and solid, but 6 of the even bank are spongy. I have taken the oil pump apart and it looks to be in fine nick. Oil pressure did seem to be low sitting at about 20psi when warm at idle.

Thanking you.

 

[keynsham1]

Does this help? I had the same dilemma recently and the various Rover manuals I have are not very clear. The Rover service manual doesn't really show it, the TVR book (it was a TVR 350i I was fixing) gets it wrong, and the Haynes manual shows both depending on which diagram you look at!!!

 

[Duane]

Yep perfect. Thank you.

 

[jp928]

Now that you have opened the oil pump, dont forget to prime it before refitting the dizzy and starting it again.

 

[Duane]

Yep.

 

[Duane]

Right next question.

This engine is absolutely doing my head in. It still has no power at all when under load. It will rev freely to 5000rpm in park or neutral but in drive it wont go above 3000rpm.

Over the months I have systematically gone through the engine replacing bits:

Started with the carbs replacing needles, jets, and float valves. No improvement.

Then found a pair of reconditioned heads so replaced those as compression was low on some cylinders (and thought maybe it was corroded seats due to the car having been off the road for 15 years). Still no change.

Then replaced the camshaft (which was absolutely poked - some lobes down by 5mm) and lifters. Still no change.

Mechanic suggested i might have not aligned the timing right hence my initial question. Very low vacuum he said. Timing cover off again to check and all was correct as per the pics.

While the cover was off I decided to pull the sump and pistons as a couple of cylinders were well down on compression. Found broken top compression rings on three cylinders. Surely that was the problem! Honed the bores and new rings and big end shells. Compression now 130 across all 8 cylinders. Still no power. It literally won't go over 60mph.

So what next? Is the cam I got from Wins International correct? Has anyone else bought one off them and had a problem. If the cam was made incorrectly surely the engine wouldn't rev freely in without load either?

I don't have a way to check vacuum, but what else could cause that to be low?

Everything is new now. Head gaskets, Exhaust and valley gaskets, timing gear, rings, carb bits?

Anyone got any clues? Is there any way the transmission could be bogging the engine down? It is a fully rebuilt BW65 and the trans mechanic said there is no way it could be causing those symptoms.

I'm ready to set fire to the thing.

Just been playing. If I put my hand over the drivers side carb intake the engine revs increase. If I do the same on the passenger side carb the engine dies. I have noticed that the mixture has to be a lot richer on the passenger side when doing the piston rise and fall test. i.e the drivers side mixture is about 1.5 turns down, the passenger side needs to be about 3 turns down. That doesn't seem right?

 

[jp928]

IIRC the rise and fall test is just to establish that the piston falls freely onto the bridge under its own weight + spring, not at all related to mixture. I have HIF6 carbs, and after a partial rebuild I followed the book - lift piston, insert ruler vertically under piston beside the needle, adjust jet so that it just touches the ruler edge, then screw in jet screw 2.5 turns. From there only very small adjustments were needed to achieve good drivability, and correct mixture. I suggest you sort out the carb discrepancy first. Any air leaks ? Fuel delivery problems?

 

[colnerov]

It sounds like it's running on only one carb. When you operate the throttle do both carbs open, not just the linkage but the butterflies as well? Have both carbs got fuel in? Check floats and float valves.

Colin

 

[Duane]

The rise and fall test I referred to was lifting the piston by a couple of mm to see if the revs rise or fall to set the mixture. Definitely different on each carb.
Will check the butterflies tomorrow.
The rise in revs when blocking one intake indicates a vacuum leak somewhere but I can't see where.

 

[jp928]

To localize vacuum leaks spray something like wd40 around manifold and carb joints and see if the idle changes at one particular spot.

 

[SydneyRoverP6B]

As others have said, having the carburettors working correctly and equally the same in terms of suction and fuel delivery is paramount. If the carburettors are out, then the engine will not run as it should. The problem may well have been the carburettors right from the start.

Ron

 

[Duane]

Probably have played a big part Ron although the engine has obviously had a rough life.
Valve guides were worn.
Three cylinders had broken top compression rings.
Camshaft was knackered with some lobes down 5mm.
Rocker shafts worn down a good mm under each rocker.
Hopefully will have a decent engine when I'm finished.