One of my engines is driven by a pro with very much more aggressive cams than those in Sean’s engine and frankly his driving makes everyone’s in lot look like pansy’s
Thats a bit harsh simon. There are a few professional drivers in the LOT series, so dont go putting people down without the full facts.
Who is this superstar pro driver??
no doubt that is why you posted the lesser engine result then?
my reply to Bernard was factual and to the point - and a reply that I have repeated to unfounded speculation.Anyone with any engineering knowledge knows belt driven cams are immune to any crank derived resonance
The page was originally constructed in 1998!, AOL lost it in 1999 when it was re-loaded. There is a lot of information on there that predates 1999, but not much from the years that followed.
I have in excess of 200 rolling road graphs here from conversions, should I post them all?
Bernard’s engine results are a matter of public record unlike some…
Making snide remarks questioning whether he knows the K has a belt drive will simply make you look foolish and arrogant.
Anyway Bernard has no case to answer, it is not his verniers that are currently in two pieces.
It’s a short road to muppetry.
Try to remain polite.
The cams are only immune from crank resonances transferred via the belt drive and they are not completely immune since a belt is not a 100% isolator.
Dave
Can I please just echo the calls for the thread to stay civil?
In the end, I’m a BIG K-Series fan and I wish Mr Erland all the best, hell if he ever publicly produces the goods of a cost-effective 250bhp K-series solution, I’ll be first in line with cash. I don’t see the need for anyone to be jumping down his throat on this one and I don’t see the need for him to be getting defensive or making claims against anyone else either.
The only fact here is that a cam pulley broke. This was a development item and as is the nature of engine development, these things happen occasionally and I hope Mr Erland gets the chance to analyse the problem. After all, FEAnalysis is only as good as the numbers and constraints applied to it. Nothing beats real-world testing.
So can we keep the sniping out of this and wait until we actually KNOW what caused the issue and what the best course of resolution is? At the moment, anything could have happened to cause such a failure, and as catastrophic a failure as it is, it look like this engine may survive to race another day anyway. I think perhaps precautions need to be taken to see this not happen again (more meat in the pulley design or better guarding etc).
For now I’ll stick with my VHPDisaster… I love it and don’t see any reason to give it up, more power will only expose how crap the driver is more!
I can’t find my K series plots now, but anyway, the 194 BHP engine was in 1999 and then I built a 217 BHP engine in 2001. So I do know they have belt drive cams.
All I can add is “After all, FEAnalysis is only as good as the numbers and constraints applied to it. Nothing beats real-world testing.”
Simon has been doing some real testing and sometimes things can go wrong.
Nobody has a problem with what you are doing Simon, it’s the economics of it that don’t stack up. My 217 BHP engine would have cost �9081 to fit at the time assuming I had to pay for labour. I dread to think how much your 2 litre will cost.
Bernard
Bernard
Whether it’s 230 or 217 is completely irrelevent. The point at issue is whether Bernard would know about the K belt drive and that your comments were just sour faced sniping as usual. As I pointed out he was developing the K series well before you were.
How many rolling road sessionsand exhausts did Uldis’s engine that had better cams and bigger TBs need to better Bernards 217BHP acheived years earlier with just one…?
Dave
FFS…you guys just can’t help yourselves can you?
its hardly surprising - sour snipes and inacurate comments are always likely to get that sort of response.
its ashame as this thread might have actually generated something useful but at least its stopped kingtwat posting in the owners cars section.
It would be easy to attack King_t, just as he does all the time to others, passing judgement on engines and parts he hasnt even seen, however everyone here has refrained from doing so, probably in the vain hope that he might learn how to act with honour and like an adult.
Bernard is a modest, talented and experienced engineer who I respect enormously; he has many more years of experience with engines than King_t will ever muster. He (amongst others) has acted with commendable restraint often in the face of aggression and made suggestions based on his experience and without criticism and mostly with courtesy.
That is why it is galling to see below the belt side swipes made at his experience and knowledge which shouldn’t be in doubt.
That is why I posted, I am stupefied by King_t’s arrogance.
There are many things I could post here which would inflame things and paint certain parties in a very bad light indeed, but I have not posted them out of respect for the BBS.
Quid pro quo.
Dave
Where is the abuse on this thread? Where have you been attacked?
You should take a good long hard look at yourself and your responses.
You are the master of abuse but don’t have the balls to admit it, that is a cowardly way to act.
“Fcking Cnt” about Steve Butt’s
“F*cking Primadonna who is trying to steal the credit for my work” about Dave Walker
I have seen many emails and letters you have sent to people which contain unbelievably insulting remarks about them and others, such arrogance is almost beyond belief if I hadnt seen it myself.
you should be ashamed of yourself.
Just have a good look at the restraint that we have all exercised here in the face of the obvious temptation and try to learn from it how to act like a normal human being.
Proven liar is not abuse it is fact with the evidence of the many instances here for all to see, people aren’t stupid, they can remember and make up their own minds.
This thread is going nowhere - again.
your post speaks for itself
Completely meaningless because you know the truth in the statements made but cannot bring yourself to admit it because I posted it, you really are predictable.
Dave
Seems to me like the verniers on Seans car have been intefering with the outer cam cover causing a small loading parallel to the camshaft. Is it possible that at 8500rpm the cyclic loading on the pulley caused by these side loads is what caused the failure?
Of course this raises the question as to why the inteference occured in the first place. Maybe there is an irregularity in the outer edge of the cambelt alleviating all blame from the pulley design, and causing panic among everybody using a cambelt on their K rather than just the few using posh metal bits?
belt side swipes
Dave
Maybe Dave already said it!
Seems to me like the verniers on Seans car have been intefering with the outer cam cover causing a small loading parallel to the camshaft
From the picture I can’t see any evidence of that, in the past I have seen the rear of pulleys suffering interference with the rear cover and this leaves tell-tale marks on the rim of the pulley, the rims of the pulleys look pristine.
Dave
the rims of the pulleys look pristine.
It’s difficult to tell from the picture, but there is more than pictorial evidence available in this thread.
when leaning into the engine bay I leant on the cam belt cover and the noise stopped, I wobbled the cam belt cover and the noise would come and go as I wobbled.
The noise was actually the pulley tapping against the outer part of the cam belt cover.
Sean…
I think it was tapping against the cover because it was broken,rather than the other way round. Normally leaning on the front belt cover forces the front cover and the rear cover back against the head, so it’s likely that the pulley was rubbing on the rear cover, leaning on it forced the cover back out of harms way.
This is exactly what happens when the rear cover distorts through heat and causes contact, when you lean on the front cover, the noise goes away.
The tell tale marks of contact are usually a stripping of the anodising back to bare ally which in turn is polished.
I have seen this phenomenon on 30 or 40 engines.
Dave
Given the speeds at which this engine was running and the profiles of the cams I’ve got to say that the torsional forces running through those pullies must be unlike anything ever seen on a K before. The amount of effort to fully calculate those forces (which I’m sure will be quite unlike a Honda which has finger followers rather than tappets) is very siginificant and expensive. I’m been away for a few days but I’ll be back in the office in the morning and I’ll put it past my cam/valvetrain analysis buddy over coffee at 9am (priorities in our office you see ).
I think this is just one of those development type things which happens when you push the envelope, but I’m glad to see that its suffered minimal damage as a result and hope that you sort it quickly and push on to bigger and better performance as a result.
(I hope that goes down as a constructive and positive sounding post, I’ll put on my flame proof overalls as a precaution though )
I’ve had a chat with my colleague and he would expect that the stab torques on the pullies of a K series with inverted bucket tappets would be roughly double that of a Honda with roller finger followers. If you need to know any more detail we can do a quasi dynamic analysis of the K in ~ a day and it would be best to do a baseline on the Honda to compare. This analysis does not account for the full dynamic behaviour of the system (that would take several weeks to analyse) but it will give a good guide figure to design for assuming everything behaves itself.
To be honest most owners are content to use the currently available verniers from Piper, Kent etc. I have installed a two or three hundred sets and seen many more and have only seen two breakages, both caused by other factors than the design. I know that at least half a dozen of the engines to which they are installed go regularly to 8800-9000 with no apparent problems. The problem appears connected only with that particular ‘improved’ design.
Dave