Too much valvetrain stress?

[350kmileford]

I read that if one has a large cam, then they don't need big rockers because it will just add unnecessary stress. I plan on getting this cam and the adjustable roller rockers:

http://classicinlines.com/proddetail.as ... 2DSST%2D10

http://classicinlines.com/proddetail.as ... D200%2DFRR

Will there bee too much stress . . Should I go with another option?

IF that setup is doable, will it clear the pistons?

(I have a 200 ci, and plan on running a high performance turbo setup w/ aluminum head, assume stock pistons)

 

[wallaka]

I don't think that you really have to worry about valvetrain stress in these engines. The primary killer of valvetrain components is rpm, followed by extremely high lift and ramp rates (which you won't find with the available cams).

I'd probably go with a smaller cam in a turbo application. Turbos don't like overlap. Does10's reported excellent results with a cam similar to this:
http://classicinlines.com/proddetail.asp?prod=CSC-274-HSP-10.

He switched to a bigger cam and hasn't had the same results. There is a discussion about this in the Turbo section, it's an interesting read.

 

[350kmileford]

I thought that hydraulic cams weren't good for higher rpm's?

 

[Does10s]

I thought that hydraulic cams weren't good for higher rpm's?

Matters what you consider "higher rpms"!

7k RPM....that's pretty high.
6k RPM....still a little high, but totally doable.

We've run the H-274 cam up to 6200 with no troubles.

We just recently used one of Mike's 292 cams. It's a good cam, but not for turbos. If we had a supercharger this, cam would probably work great.

For a turbo motor I'd recommend going small. You want no or very little valve overlap.
We're going to try the 278 on a motor very soon. Not Kelly's car, but another one.
Clay Smith is grinding a new cam for us as we speak. We should have it running next week. It should be setup as a "turbo specific" cam.
I'll let you know how it goes! If it goes well maybe Mike will stock it!
Later,
Will

 

[350kmileford]

Yea buddy!

If it works out I will be ordering one as well. What was/will the total cost be?

So, if I were to use the cam you're having made, I could use the roller tipped rockers and oil through hydraulic lifters (Even though the oil through lifters claim to work with only the full adjustable?

http://classicinlines.com/proddetail.as ... D200%2DRTR

http://classicinlines.com/proddetail.as ... D200%2DSBH

...which also confuses me.. Hydraulic lifters with adjustable rockers? I thought that adjustable rockers were unnecessary on hydraulic lifters?

 

[Bort62]

They are unnecessary, but useful.

Keep in mind Will has a much higher flow head than you do, so his cam choice is not going to be idea for you. Most likely, it will be too big.

 

[Does10s]

The cam that Clay Smith is grinding for us will use solid lifters.
The oiling lifters (hyd. or solid) are a must with the roller rocker arms made by Yella Terra.

Ian,
If he's getting an aluminum head, then he'll get exactly the flow chacteristics that we have. Our head is right out of the box.
So I hope that this new cam will work.

As for the cost I don't have a clue. That's up to Clay Smith and Mike at Classic Inlines.
I believe that Clay Smith was able to use a standard cam core so the cost shouldn't be much different than normal.
Later,
Will

 

[Bort62]

I didn't notice he was going w/ the AL head.

I read WAY too many posts... they all start to look the same.

 

[addo]

I would suggest a 200 and a 250 might use different grinds with the same head. The flow won't develop in quite the same way for each motor.

 

[350kmileford]

Well that's true. Guess I am back to square one. I'm still up for a good recommendation on a 200 turbo cam.

 

[Bort62]

Well, what are you trying to accomplish?

 

[350kmileford]

I'm thinking, will they really be much different? I figured that with forced induction, the cam would produce similar properties in either engine.

 

[wallaka]

All else being equal, the 250 will need a "bigger" cam than a 200. More displacement = requires more time to fill the cylinders.

 

[AzCoupe]

As for the cost I don't have a clue. That's up to Clay Smith and Mike at Classic Inlines. I believe that Clay Smith was able to use a standard cam core so the cost shouldn't be much different than normal.

If they used a stock master to grind the cam, it only cost more when its a custom one off. However, if I decided to offer this profile and have 20 cams produced, the cost would be the same as any other cam I have in stock.

 

[350kmileford]

So would this be a good cam? Running a manual tranny, ported/polished al. head, 10-15 psi... 200ci!

http://classicinlines.com/proddetail.as ... 2DHSP%2D10