Any cam and cam timing experts? Need advice!

[Paddy_g46]

Basically i have bought a car (mk1 valver) with kent cams and vernier pulleys, and a gas flowed/ported head but the guy who had the cams fitted had the pulleys/timing reveretd back to standard as he says it was very lumpy idle and he didnt like it? He said he has marked up the pulleys etc with the new timings should i wish to put it back to how it should be​

My question to you guys is how much of the cams potential am i loosing due to them not being on the right timings and is it easy to change them myself considering they are marked up?

And is a remap a worthwhile thign to do once i get the timing sorted?

Sorry if any of this doesnt make any sense all this stuff is new to me!


Patrick
​

 

[BenR]

Potential depends on the cams your running.

Its easy to put the pulleys on (essentially a cambelt change), but if you have to ask how to check the timing then I wouldnt attempt it. Just because he marked up the pulleys doesnt mean that they will be in the correct position, as soon as you de-tension the cambelt or take them off, all previous markings are pretty much null and void.

You WILL need a remap.......

 

[Paddy_g46]

kent cams 1601 are what its running, the engine was only rebuild 4k ago with a new cambelt etc. So can the timing nto be adjusted without a new cambelt etc? How much of a job is it? How much will it cost me to get it done?

If i dotn remap it will it run badly?
What sort of gains would i be getting currently if its on standard timings/map?

 

[BenR]

5 questions in 4 lines........some sort of record there!

You can install vernier pulleys without changing the cambelt, but the risk is on your shoulders.

Like I said, the job is essentially the same amount of work as a cambelt change.......with another half hours fiddling to set the valve timing.

Cost depends where you go, their labour rate and how long they take.......and if they know wtf they are doing.

It WILL run lumpy, even with a remap.

Gains I cannot comment on........there is every possibility that you could do all the work and gain nothing. Nothing is set in stone.

 

[Paddy_g46]

Im not fussed about running lumpy, i quite like the sound of a lumpy idle! I just want it set up to be running at its optimum, no point in having unused potential!

Possiblity of no gains? surely not!?

 

[BenR]

fraid so......hell, there is the chance that you could adj it and loose torque at low rpm and not gain any up top.

If you want it at its optimum you will have to hand it over to someone who can spend a few hours on a RR swinging the timing around to find the optimum curve, and that lot will cost a small fortune.

The word optimum and cheap never go hand in hand.

The best you can do is set the timing to the kent cams book valve timing events, check the power before and after then see how things go from there, nobody can give you a black or white answer i'm afraid.

 

[Paddy_g46]

ok, thanks alot for the advice mate, if its going to cost that much then i think ill leave it! As for the book timings, any idea where i can get them?

I think ill get it rolling roaded at uni and see what power its putting out and go from there!

 

[BenR]

kent website would be a start.

 

[Icarus]

If you want it at its optimum you will have to hand it over to someone who can spend a few hours on a RR swinging the timing around to find the optimum curve, and that lot will cost a small fortune..

Yep! 40 hours + so far on one of the BTCC engines and still not signed off!

Cheers
M

 

[sideways danny]

If you go by the kent figures you should notice it will run a lot better even before you get it mapped (which you will need doing) Did one very recently that had been lashed together with guesses timing, and the transformation was huge, though very noticable that the fueling was way out

 

[Paddy_g46]

So do i have to get it mapped as it is? its currently running standard timings.

 

[sammyhale22]

You want maximum valve lift at TDC with high profile cams!

 

[sammyhale22]

To continue this thread a little with my own question. What are the gains of replacing the VVT system with vernier pulleys? I would guess the most obvious is reliability as the dephaser seems to be quite weak on these engines, but do you lose power by removing the VVT as there will be no timing advance or kick at 4k?

Samuel

 

[Ad172UK]

IIRC You lose the 4k Kick, But gain the power lower down the revs, -4k.

That's how i understand it anyways, but i may be wrong.

 

[mini-valver]

VVT comes in at circa 1.5k rpm and has nothing to do with the kick you feel at 4-5k.

 

[Ad172UK]

Damn, I could edit my post i spose, but then the thread won't make sense, so i shall just man the f**k up and take it on the chin!!

 

[Andrew Cooke]

You want maximum valve lift at TDC with high profile cams!

is that maximum lift at TDC for the inlet, exhaust, or both cams:hail:

 

[sammyhale22]

Inlet maximum lift I believe. If VVT comes on at 1.5krpm, how come my revs don`t feel consistent , for example just after 3k it feels like it loses its UMPH, then at 4k it launches. I`ve also noticed down low 1-3k my engine feels punchier when the engine is cold than when its warmed up.