interference issues?

[05Gibbs]

im building a 383 stroker with all forged internals and it has 6in rods and the block has been decked to 0 i was originaly going to run a hydr flat tapped cam but im going to go ahead and run a solid roller cam but my main question is am i going to have any issues with valve and pistins clearance i have no idea on how to check this or what amount of lift one can handle without parts hitting im using 1.6 rockers also this is the cam im looking at http://www.compperformancegroupstore...ory_Code=SMRXE any help will be much appreciated thanks bryce

[kenm78]

I would rethink the 1.6 ratio rockers with that cam. Comp cams recommends a 1.5 ratio rocker with that cam. With the 1.5 ratio that gives you .576/.582 lift at valve spring. With the 1.6 you would have .616/.622 lift at valve spring. I would take the cam and rods to the person who performed the machine work and let the machinist check the clearance. Might be too much with 6 inch rods but I'm no machinist. What is this bad boy going in? Is it going to be naturally aspirated, or have a blower/charger on it?

[cableguy0]

the only way to really know for sure is to just put the heads on with the gaskets and use modeling clay on top of the pistons then spin the motor over. you really only need to put the valvetrain together on one cylinder. after you spin the motor pull the head back off and measure the thickness of the clay where the valves made contact

[05Gibbs]

well i allready have the 1.6 rockers that go with my trickflow heads but i guess i could get new but anyways are u talking about the rods and the cam lobes hitting or valves and pistins hitting and i dont really have the money to get everything and have it not work ya know? i have always ran flat tapped cams so im used to low 500s at the most so when all the roller cams say 600 or so lift will these work most generaly why is their such a difference? and its going in a 81 shortwide pro street wanna be truck lowered 6-8 and alot of weight reduction

[05Gibbs]

and my have a 150 or 200 wet plate kit no charger or turbo

[cableguy0]

solid roller cams are going to be big. you need a small base circle to clear the rods either whether they are 5.7 or 6 inch. i was talking about valve to piston clearance which also needs checked in that lift range. i think you probably need to be at a hydraulic roller cam which will be a lot more streetable and still make good power. you wont have to run ridiculous valve springs and pushrods etc. a hydraulic roller is a lot easier on the valve train and wont need adjustment all the time.the cam your looking at is just slightly larger than the hydraulic roller im running.

[05Gibbs]

whats a small base circle? i have hered of that but never had any experiance with one or even seen one for sale how do u tell if its a small base circle

[cableguy0]

they will be sold as a small base circle cam for strokers. the cam itself is actually smaller in diameter. as i said the only way to be 100% is to have it checked. get in touch with your machinist. some rods are clearanced and they will clear the normal cams. once you get into bigger lifts things just have to be checked to make sure of clearance. you need about .050 between the rod and cam to insure it cant make contact.

[05Gibbs]

im pretty sure the cam that was in this engine was not a small base circle cam my rods have cap screws and have been grinded on so im guessing that to clear the cam

[cableguy0]

yes that would be to clear the cam but it depends on the amount of lift. it should always be checked especially once you get into the .600 lift range

[chevybuldr]

If you are going with that much lift on a cam I would bet you are going to have piston to valve clearance problems. Trickflo heads I believe they have they canted valve? That could also be an intersting problem. Get some clay and roll the motor over a few times. You have not said what pistons you are running. Also make sure that you time the motor as you are going to run it. As in dont check it and then cut the pistons and then degree it or do what ever you are going to do as in retard it or advance it.

[swb85]

Remember that a camshaft's max lift at the valve has VERY little to do with how much piston-to-valve clearance you'll end up with.....it's the duration of the lobe is what will determine clearance. You can have a very long duration cam with only .500" lift and still smack the pistons......if you're not familiar with any of this I highly recommend letting your machinist take care of you.