Thread: Roller rockers

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you will need guide plates installed into the heads, you can do the drilling but i recommend having a machinist do it since you're never done them before.... also you will need hardened pushrods or else the guide plates will eat right through them..... the 1.6/1.5 setup is good even for a non race motor, the rocker ratio affects cam lift, but it depends on what cam you already are using and what kind of valve clearance you have, if you have a stock to mild cam it can be an easy way to get a little more juice out of the motor, i've never done it myself though so i'd wait on someone with a little more knowledge on it...

Thats great, but if I use 3/8" studs, I wont have to drill, or are the original, pressed in studs? If so that makes sense. On the pushrods, why do they offer the +.100" rods, is that somehing you need to do to correct geometry or something, or can you renain at std. Are the +.100's for the 1.6's and the std for the 1.5's. Told ya this was new to me. Thanks.

I'm no expert on roller rockers, and luckily the two engines I have that have them were done when I got them, but I do know that when you install the guideplates they are secured by screw in studs, and that the heads need machined to accept these. I also remember that it is more than just tapping threads in most cases, you have to have some of the boss machined down to lower it a little. I think the guide plate kit will probably include directions??

As for different length pushrods, I didn't know these existed until I took my newly running 302 in my '27 in to have the exhaust system done. When it was all capped up and quiet, the guys at that shop (who build race engines) said it was not running right. Sounded ok to me, but they really know their stuff. I told them to fix it, so they installed shorter pushrods to correct the geometry and when I picked it up the car did sound much crisper and ran better. Maybe the head surfacing took off material that changed the length needed?

All this finite stuff is way beyond my pay grade, so I leave it to experts, like some of the guys we have on here.

Don