268 cam lobe failure

[Streaky]

I've joined this forum because I've experianced some problems with my 4.6 engine and no one seems to be capable of giving answers or solutions.

I purchased a Kent cams MDC1 268 and a Vernier Power pulley to compliment it. My mapping is via a Mark Adams Tornado 4.6 hotwire 14CUX.

When it came to fitting the vernier pully my workshop found it impossible to line up the timing marks correctly with those on the cam and the crank. We ended up leaving the vernier Power Pully off from the build and we used a slightly modified standard set of sprockets instead.
The cam came with a set of twin springs so these were installed at the same time along with new stem seals.

After approx 4000km the engine took on some backfiring and popping under acceleration. A strip down of the top end revealed a missing lobe from the cam on cylinder number 3. The tappet was dished also with signs of heat tracking.

My questions are these.
What could cause a single lobe failure? It was completely missing from the cam! All other lobes and followers are fine.
Could the twin springs contribute to such failure?
Is it possible that the manufacturing of the cam is wrong? The woodruff key may have been machined out of spec? Could this be why it was impossible to get the cam timing correct?

My workshop have build a huge number of Rover V8's in their time and yet they couldn't get the power pulley timing marks to line up. They built my previous 4.6 to a very high standard....but everyone can make a mistake right

The cam and tappet was returned to Kent Cams over a month ago but I have not received any feedback as to what could hae caused this.

Any feedback from here would be welcomed. Something must have caused the failure...either fitment,set-up, running in procedure, wrong specs of the cam?
The annoying part of this is that I have paid out hundreds of pounds for parts and the same in labor charges..but no one wants to take responsability for their workman ship or stand by their product.

[350matt]

Sounds unfortunate

Could be a couple of things:
Is there any coil binding, valves hitting piston etc on that cylinder?
What was the lifter pre-load ( any records during build)
Are the oilways to that lifter blocked

As its number 3 that failed its sounds like the main cam gallery is fine and your oil pressure is also fine.

If none of the above then your're looking a poor quality casting for the cam, do you have the missing cam lobe fragments or was it gorund away?

The only other thing is the difficulty in fitting the vernier wheel. As most build shops shouldn't be relying on lines on the cam / crank etc but should set it up from first principles, measuring lift on overlap etc

That said even if the timing was out the cam lobe should still be in one piece, unless its was so far out valves were clouting pistons

Matt

[Streaky]

Hi Matt.
Thx for your response.

There was no evidence of coil binding and I didn't see any whitness marks on top of the pistons to indicate valves hitting the crowns.
I wasn't present during the final fitting of the rockers but I believe that no pre-load was set during the instalation.
I know that the heads were both skimmed previously and that the garage was aware of the heads condition...would that perhaps promote wear on the single lobe then

My oil pressure is fine and there was no evidence of blocked galleries. I wasn't always present during the build but my workshop would have told me if they'd found something out of the ordinary.

The cam lobe was completely worn away and we couldn't find any trace of it. I had the engine flushed a few times over to remove any fine fillings from the cam.

During my presence I know that the mechanic did not use cam assembly lube. To what extent could this have caused the failure Bearing in mind that I have two springs per valve... Can you get away without using assembly lube or should it be done as matter of presidence when fitting twin springs

My garage told me that there was a problem with the vernier power pully and that I had supplied them with the wrong one.
Luckily for me I happened to be travelling back to the UK that same week so I took the pully back to the supplier who confirmed that the kit was correct to spec and that nothing was wrong with it.
I wish I'd had a chance to inspect the cam properly before sending it back to Kent cams. Do we think that they will admit to a problem with the cam or will they simply try to blame the installer? They've not been responsive to my UK supplier.
I was present during the fitting of the pulley and although I'm no expert it was clear to see that the timing marks didn't line up in accordance with the fitting instructions.
Instead, the garage took a regular set of timing gears and modified them to get the cam timing correct.
Here's where hind-sight sets in and unfortunatly for me I was doing all the work on a mobile phone between Uk and Dubai.

Thoughts & comments welcomed.

Thx.

S.

[ian.stewart]

think you have got it in one,
"During my presence I know that the mechanic did not use cam assembly lube. To what extent could this have caused the failure Bearing in mind that I have two springs per valve... Can you get away without using assembly lube or should it be done as matter of presidence when fitting twin springs,"

Any cam should be assembled with lube, and its reccomended that the engine is run @ 2000rpm for at least 20mins to bed the cam in.

Rover Cams at best can be describe as a consumable, probably need to change them on a performace engine every 30k max, No one seem to be able to tell me why there is this problem, but I am having a new cam made for my engine at the moment, and also having a set of custom solid lifters as well [case hardened steel], the best theory that I can find is the RV8 cams made in this country are , made from Chilled cast iron, the followers that are normally fitted are Chevy derived and made in America to different material specs and as such are incompatable with the chilled cast iron,
TBH I have had trouble with cams made by Kent before with lobe centre variations of 13 degs on a 4 cyl engine, and personally i wont use them, My cam is being made by David Newmans, he has been making cams for years, and is one of the easier people to talk to,
http://www.newman-cams.com/
Ian

[350matt]

No assembly lube...... owch

That'll be the problem, as Ian says the rover lump gives its cam a hard time anyway, and yours wouldn't be the first cam wiped out after an hour when the fitting instructions have been misinterpreted.

I'd also vote for Newmans as well.

As another alternative V8 Developments do some cams for the RV8 which are superior to the Kent stuff in terms of performance


Matt

[Streaky]

I've already been in touch with Sean @ V8 D's...he's been extremely helpfull.

In an effort to get my money back for the damaged cam I'm going to point my finger to one of a few things....not setting the pre-loads correctly & failure to use cam assembly lube.
My garage were aware that the heads had been skimmed so they should have made provision for this when re-assembling the top end.
Combine the lack of cam assembly lube & twin valve springs and I think I have a strong case for a refund due to poor instalation.

Thoughts?

[sidecar]

I've already been in touch with Sean @ V8 D's...he's been extremely helpfull.

In an effort to get my money back for the damaged cam I'm going to point my finger to one of a few things....not setting the pre-loads correctly & failure to use cam assembly lube.
My garage were aware that the heads had been skimmed so they should have made provision for this when re-assembling the top end.
Combine the lack of cam assembly lube & twin valve springs and I think I have a strong case for a refund due to poor instalation.

Thoughts?

Just read your other post about this engine, your not having much luck!

I'm not sure that you will get your money back but its worth ago.

To be honest if your engine is in pieces I'd rebuilt it myself if I was you, I built my 4.6 from bits and I know that I took more care then anyone being paid to do it would have done.

I spent many hours getting things like the pre-load spot on as I believe that the "Devil is in the detail" when it comes to getting the best out of an engine. I'd go for adjustable pushrods and set the pre-load to 20 thou. (not the 40-60 that is often quoted).

Basically I built my engine using Des Hammills book, it is required reading when messing about with Rover V8's.

Pete

[Streaky]

Can anyone tell me if V8 Develeopments are still in business? In the past 6 weeks I've sent them 4 emails and left three messages on their answering machine.
I can understand companies having email issues, but to only ever get an answer machine when I call them has me wondering whats going on.

I bought the cam shaft kit from them for 400 pounds so that makes them the supplier and responsible for my aftersales.
I then had to return the cam to the Uk (more expense) for an investigation on how the cam lobe might have failed. I know they received the cam by way of registered post.
But ever since then I cannot get in with them.

Any ideas on the wherabouts of Sean and Ray? Hope fully they'll see this and respond.

Thanks.

S.

[mrcheese]

You don't seem to have a lot of luck with contacting UK suppliers do you, Streaky.

Can I suggest a certain Mr Lund.

Sorry, I'll get me coat.

Whatever happened to that engine he built for your 130 about four years ago? I remember being there when it was built up. A very nice looking twin plenum set up IIRC.

I don't mean to open old wounds. Just a bit of banter from another former customer. What is Team Saluki racing now?

Regards,

Paul.

[Streaky]

Hi Paul.

Correct mate...UK suppliers don't always live upto my expectations in terms of after sales service. I set my standards quite high and expect the same from those who take my hard earned money. I see no harm in that

Hmmm...my 130 engine with blue rocker covers. That brand new engine dropped it's oil pressure within a few hours of being fitted. Upon strip down it revealed that certain shells and bearings of oversized tolerances were used by the builder .
The block was then line bored, new shells, bearings, cam shaft alligned etc etc and the rebuilt. I got most of my money back after a year long battle.... and the engine never faultered after that.
I recently sold the 130 to Sheik Hamad Hamdan the Rainbow Sheik. He's building a 4x4 version of a Rolls Royce Phantom IV 1934 spec and he needed a long wheel base donar vehicle with decent HP. He called me up and made me an offer I couldn't refuse....so now it's stripped down and being re-worked.
That same engine was dyno'ed by V8 D's before being flown over here. It's for this reason that I'm surprised that they haven't been back in touch with me. I have a very good relationship with Sean and I was just wondering what on earth could have happened to them. I paid V8 D's a visit last year and have no probelms with them apart from not being able to get a response about the failed cam that I returned for analysis.

The twin plenum was another 'Blue' engine that we had. That was in the racer but we removed it in favor of a more reliable and tuneable single plenum. Castrol analised our oil and found that the twin plenum was over fuelling and bore washing the engine. No matter what we tried we couldn't get it to work properly so the engine was send back to V8 D's for a strip downand yet another rebuild.
The Saluki was then sold to a couple of Canadian guys who recently competed and finished the Californian Baja 500 in it. Mark now runs a 2WD Fast & Speed buggy from Holland with a V6 Honda engine. I've left the team now and race T4 Rally raid trucks instead.

If anyone gets a chance to talk to Sean or Ray, please ask them to take a peek in here or get in touch with me. Emails have failed to get a response. Messages on their answer machine are not addressed.... I have a right to be concerned about the 500 quid I spent with them I think.

Thanks.

Regards.

S.