4K Cam Grind Options

[camKE55]

Hi all, just wanting to gather some information on cam selection.

i have a 4k motor with a webber 32/36 exhaust and extractors and a mild head recondition.

 

spoke to a bloke today at waggott cam and he reccommended a 212 grind??

just wondering what grind i should look for, i use the car as a daily and i want to get the most out of her. with a nice lumpy idle of course ;)

cheers Nathan

[B.L.Z.BUB]

Talk to the cam grinder, he will know what is best. Its their job. Explain exactly what you just wrote.

[camKE55]

cheers, yeah he said a 212 grind.

but just gathering information and seeing what other people have used and what works for them too :)

[corollaart]

All so check out tighe cams ,ok to deal with.

 

Lumpy idle may not be always the best solution ,but cool to wank with.

 

But be realistic ,over camed will be a dog.

[camKE55]

yeah fair point if its going to be a daily then it needs to be enjoyable and not a pain to drive, cheers man,

[altezzaclub]

I collected these when I was looking at cams under 275deg. Lots of guys get hotter ones, but they do become difficult to drive in traffic if they're working properly.

 

I picked the Crow grind because it opens faster than others, as you can see by the 50thou readings.

[coln72]

Was happy with a Wade grind in my 5k

[camKE55]

would a 212 waggott grind be too much for the 4k??

[altezzaclub]

Anything will run in a 4K, so long as you have the rest of the motor set up for it.

 

You'll only know when you try it- Hopefully someone else has used one and you can drive their's.

 

They lose low-down performance because the inlet valve stays open so long that fuel/air gets pumped back out as the piston comes up. Only when the revs get up and the airflow velocity increases does the air get enough inertia to keep filling the cylinder against the rising piston. That cam won't shut the inlet until about 80deg before the spark plug firing, while stock is about 115deg before the plug fires.

[camKE55]

ok cool, yeah will be doing mild work to the engine. I want it as a daily not a race car. just collecting as much info as possible before i get it done.

 

would you reccomend any grinds?

 

cheers mate.

[altezzaclub]

Well, I've got a 270deg cam, that Crow 606, and it doesn't feel cammy at all to drive. The idle is vey grumpy, but that is also to do with the twin carbs and maybe the leaness. It idles at 1000rpm.

 

PM EvanG and see what he uses with his Weber, they're a pretty popular carb. The Tighe 104 is pretty popular on here I think.

 

I'd say go with anything around 275-280deg, you can chase up the cam grinders I got that data off and see what else they offer. With a bit of luck you'll get comments on here from some of the guys who have tried more 4K cams that I have.

 

If you have the motor out it is well worthwhile getting the flywheel lightened a couple of Kg and the whole lot balanced.

Edited August 23, 2012 by altezzaclub

[Evan G]

i replied to his pm. also when refering to cams please go by the DURATION @ 50 thou. this is a more accurate way of dermining the size of the cam

[altezzaclub]

Why is that Evan? I imagine very little happens in that first and last 50thou as the valves are closing or lifting off the seat, but the figures in the table do show that some cams are much more aggressive once they take up the tappet gap. That was why I picked the 606 grind for Orange's higher altitude, we need lift and less duration than sea level.

 

Here's the hotter cams off Tighe and Camtech. Most the grinders don't list K motors on the web anymore... Seems that Tighe have low 50thou duration compared to their advertised durations.

Edited August 23, 2012 by altezzaclub

[camKE55]

ahhh those charts are helpful!!! thanks heaps for the advice fellas. muchly appreciated!

 

cheers

[camKE55]

i have some research and thinking to do hahah :)