I am talking with a fairly well-known engine builder who has built about 5,000 engines like the one I am requesting..a street/strip 6-71 blown 355 SBC.

I want a mild hydraulic roller cam. He advises a hydraulic flat tappet and refuses to install a roller unless it is a solid roller. His rationale is that he has tried hydraulic rollers before and they often fall apart on him. When I brought up the fact that even production cars run 100,000 miles on them now, he responded that is because they don't see high RPM like a performance engine does.

My belief is that, hydraulic rollers do tend to run into valve float more easily than a hydraulic flat tappet because of the faster ramp rates of the roller, causing the rollerized lifter to dance on the cam lobes at very high RPM (6500-7500rpm), pulverizing the roller lifter. I don't think the risk is as high for the mostly street motor I want that will rarely see 6,000 RPM and have only .480-.500 lift. Any opinons on this logic?

Also, I am thinking about a torquier 383 instead of the 355, but again the builder is advising against it saying that because of the geometry, supercharged 383's tend to run very hot and thus refuses to build supercharged 383's anymore. Any informed opinion or info out there on this?

One more..anyone out there have good results running a 1.5 ratio rocker arm on the intake valve and a 1.6 on the exhaust side? Anything funky happen?

you plan on driving a blown car on the street....hope the gas aint too expensive where ya live ;)

Gasoline is expensive everywhere else except the States and overseas military bases.

I believe you should be fine with the low-compression 355 and 5-7 psi intake. You would have to experiment with the rockers, but, 1.6 would do well on exhaust. Don't forget to lengthen the pushrod hole in the head to accommodate the higher ratio. The drill index can be purchased and use a quality drill bit. Do both int & exh for future use.

I would listen to the builder. If you don't like his mindset, why did you choose him? Experience!

With a blower you want it all. Looks, sounds, power, fame, etc.

I like the proven reliabillity of the hydraulic flat tappet cams in this application. Nothing against roller cams at all. You will have it all with the blown 355 he knows how to build for you. You will probably have so much torque you will never even get it to the ground.

Everything over a mouthful is wasted! :D

-Mark.

Use a mild 270/230, .480" to .500". 114/108, solid and poly-loc's and pick up a bunch more power!! So what if you have to lash them every so often??

I guess I'm for the no break solids!!! pdq67

PS., maybe go 275/235???

I'm sorry, over the hydraulic cam, not the hy-roller... pdq67

Never built a blower motor. Never even driven one. BUT if I were to build one I would want the absolute most reliable valve train money can buy. Same with fuel system and ignition.

Yes you might be able to squeeze a few more HP with a hydraulic roller over a hydraulic FT but who cares? If you want more power just change the pulleys for a couple extra pounds of boost.

I'd listen to the guy . . . Sounds like one cool project graemlins/thumbsup.gif pls come back when its done and post some pics :D