It is time to order timing set for my 502cid peanut port engine. Cant find much info about the cam put few people here claims that it is ground 2 degrees advanced. LSA 110. ICL 108. 224/234. Adv. Duration? Zz502 peaks at 5200rpm and make almost the sama power at 5700rpm. My heads are much smaller and wont carry the power that far so i started to think, would it be wise to advance the cam 4 degrees more or something to make more torque/hp at lower rpm. I dont need power above approx 5200rpm. Can someone calculate the best valve timing events to this engine with this cam. My peanuts flow numbers are similar than zz502 heads except higher lifts (lifts over the camshaft max lift) low and mid lift flow is even better.
Everything is like the zz502 except heads and crane gold 1.7 roller rockers. Engine is going to a boat. I just have a feeling that in my rpm range i will waste power and torque. Any toughts?
He can send it to me instead, as a budget cam in a mild build its a decent cam used several over the years in 454’s one with Edelbrock rovals, a couple with oem ovals and even in a 496 with brodix race rite heads.
I have a couple of them and they are nicely made cams. For your application I think you're good to go. This cam was a compromise between high HP and longevity just like a production engine. Based off info from Straub this was made for the GMPP/Edelbrock heads based off the total and .050 duration. I'd put it in straight up since lower head flow needs more duration to compensate.
Straub use to advertise a cam specifically for the ZZ502. Would be worth looking into. Or maybe one of the Clay Smith grinds he designed would work for you.
Going to use 1.7 crane gold roller rockers. just going to my garage to measure how much crane golds gives more valve lift, Wizard claims that they 1.77 in real world.
Oddly I measured lift using stock gm rocker arms with the 502 cam and was surprised to see the ratio was more than 1.7. It was like 1.76 IIRC
There is a 69 Chevelle here with a stock zz502 which has broken into the 10’s. Just goes to show that most folks insist on using a cam that’s too big for what there doing, but so long as their told they have the wrong cam they’ll continue making wrong choices.
the most classic hot rod builds have too much cam, too big carb, too much compression, too big headers, too low stall speed converter and too high gear.
check the first line of Vince's sig for an example of how to do it right. Notice his MPH would support a lower ET.
Rocker arm ratio measured aprox 1.74. Intake, 0.309" lobe lift, valve lift 0.537", with 7.57" pushrod lenght ( the most lift). Did it also following straub technolgies instructions, valve lift 0.536", pushrod lenght 7.72", I need longer studs with 7.72" pushrods.
My friends nova runs low 11s with one of those zz502 cams. He’d like to buy another if possible
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Related Threads
?
?
?
?
?
Team Chevelle
5.1M posts
115.6K members
Since 1998
A forum community dedicated to Chevrolet Chevelle owners and enthusiasts. Come join the discussion about restorations, builds, performance, modifications, classifieds, troubleshooting, maintenance, and more!