[HQHolden]

I have a set of sportsman II's for a SBC. I can't install 1.6 ratio rockers on the intakes because the 3/8" pushrod is fouling on the hole in the head. I can't drill the holes out bigger because the ports have had material taken out of them. The holes will have to be offset bored towards the rocker studs (making them elongated).

Has anybody experienced this problem? Has anyone else got this setup and not experienced any problems? Does anyone know how far they can be machined without going into water?

Thanks for any help

[Rogers Performance]

Why are you using 3/8 push rods instead of 5/16?





mike

[Robbie]

was thinking the same thing mike!!!..I have the same heads as he does,and i have 5/16 push rods with 1.5 roller rockers..and my lift on my cam is 560,and i have no problem
Robbie

[HQHolden]

Mechanical roller + 630 lift + 260deg + heavy springs + 7500rpm + 5/16 push rods = boomerang shaped push rods.

I think the area between the push rod hole and the stud is solid anyway (no water). So I can machine out whatever I need to.

[tresi]

Originally posted by HQHolden
I have a set of sportsman II's for a SBC. I can't install 1.6 ratio rockers on the intakes because the 3/8" pushrod is fouling on the hole in the head. I can't drill the holes out bigger because the ports have had material taken out of them. The holes will have to be offset bored towards the rocker studs (making them elongated).

Has anybody experienced this problem? Has anyone else got this setup and not experienced any problems? Does anyone know how far they can be machined without going into water?

Thanks for any help

For break throughs between the pushrod hole and intake port I've seen people ream the hole to a light press fit for a piece of thinwall brass tube. Press the tube in to plug the break through and give it a thin coat of epoxy just to be sure it's sealed.

[killerformula]

Originally posted by tresi
For break throughs between the pushrod hole and intake port I've seen people ream the hole to a light press fit for a piece of thinwall brass tube. Press the tube in to plug the break through and give it a thin coat of epoxy just to be sure it's sealed.

gawd, that sounds aweful

K

[lluciano77]

With all that cam, why are you running Sportsman IIs? You've got a little bit of a mismatch. The ballistic amount of lift you are running is being wasted on the mediocre flow ratings of your heads.

I hope this engine is built for race only use. Otherwise, I would pick a more down to earth camshaft. Either that, or at least get a set of heads worthy of the cam and hardware you will need to keep your valvetrain together.

[Cstraub]

Cam is not that big for a 5/16" quality pushrod in the 80 to .113" wall size. Smith brothers makes a good piece. 3/8" is only needed in high rpm 8K plus to control deflection.

Chris

[johnsongrass1]

You said it Cstraub.


You can also run solid push rods and a rocker oiling system with a solid cam.

[HQHolden]

Ummm......yeah...thanks guys.....thanks a lot

Not being rude but did I ever mention what my heads flow? How can anyone assume that I have too much cam or not enough head or wrong use or what ever? My heads are not 'out of the box' and my combo is very well matched. In fact I need more cam and that's why I'm going with the 1.6's!

[Cstraub]

Just a note, if you go shaft rockers, get a pushrod with a 210 radius to avoid spitting our pushrods at high rpm.

Chris