Boomerang Baba

Learned Men..
I got back my GTS cams from K Cams in Norway.
They now have 270 degrees in, 266 degrees ex
What does that mean?
Are they similar to GT cams now or more hard core?
They were 255 in and 240 ex before, according to K Cams
What are the numbers for GT cams?
Cheers, Michael

Mike Simard

That means nothing without knowing the lifts at standard amounts such as 1mm or .050". There's an infinate possibilities for ramps and profile. presumebly those are your seat to seat numbers, do you have anything else?
Descriptive basic cam numbers would be:
Lift
Duration @ 1mm or .050
Intake centerline to set the engine up to.
Lobe centers, intake to exhaust centers OR alternately, open and closing points at a certain lift for both intake and exhaust.

You'll need those when setting them up in the engine.


Since they are regrinds, the new profile has to fit which makes it tricky to have ideal acceleration. there's also the sprocket teeth which force the intake to exhaust relationship.

Lizard928

As Mike has said, you need to get the duration @ 1mm (.040") or preferably .050" lift, as well as the lift.

No one uses total duration numbers anymore.

mark kibort

did you grind down the base circle?? you need to get the lift up to the GT specs. and possibly more.

Boomerang Baba

I forgot to write 1mm lift...!
Sorry.
Just a regrind of the stock cams.
No material added.
That`s all I know.

Vilhuer

Measure their lift now. Stock intake is 9.5mm and exhaust 8.5mm.

andy-gts

I have DrNick's gts cams that had the base circle reground and my rwhp went from 324 to 348 ..some improvement I guiess. that was with headers and 3 inch dual exhaust. I just expected more...I was some what disappointed. But I don't know much about the science behind the grinds etc.

andy

ROG100

My "Jim Morton" S3 street grind - slightly better than GT - gave me what feels to be a ton of HP on my 93GTS.
Once I have finished the ST I will dyno and find out what it really was.
IIRC it went from 280ish RWHP to 320ish without the ST.
After the initial ST it started to pull like a train between 4k and 6k.

928mac

Thats what matters the most is if the grind gives you the kick in the pants after. Then as Roger says, when you strap on the lungs, she should pull like a raped ape.

Roger I see you have the fuel lines for under the hood, could you please add those to my order. Thanks.

Brad

ptuomov

When my stock engine gives up, I have a low compression engine waiting to go in with Jim's cams in it. Maybe I should start a thread on that engine?

GregBBRD

If they took more than about 1mm away from the base circle, you will need to add some lash caps to the top of the valve stems, so the lifter runs in the correct position and has some pre-load.

pcar928fan

I need what Roger has...

Boomerang Baba

Roger: That sounds like fun!
I think mine should be similar.
The cam tech told me (just as you did Greg) that I needed lash caps if I wanted more aggressive cams.
I gave him 4 S4 cams.
He said they needed lash caps if they were to be worth investing money in.
They only give 0,5mm lift sans lash caps.
How far can we go with lash caps?
1,5mm..?
2mm..?

mark kibort

1mm of base circle grind increases lift by .5mm or 1mm? but the lifters can handle that without lash caps, correct? (as Dennis did with his modified GT cams)

RyanPerrella

starting with stock GTS cams to have profile work on them is probably the worst cam to start with.

I find it odd that you would have that kind of work done and the work involved in removing and refitting them and not have any concept of what the cams do based on you not knowing what any of the numbers involved have to do with anything.

Sounds like having work done just for the sake of doing work and spending money. I hope you get your money out of the cam swap but something tells me your going to be very disappointed.

Andy, what are Dr.Nicks cams? are they regrinds, if so off of what base cam set?