Forum » How to Degree a Cam » valve to valve clearance not worth considering?

valve to valve clearance not worth considering?

How to Degree a Cam

Forum Posts

Courses

Blog

Tech Articles

Discussion and questions related to the course How to Degree a Cam

= Resolved threads

Page 1
Author
90 Views

Now that I've been through this whole course I've realized that there wasn't much of a mention of valve to valve clearance checking and only p2v checks for the process given. Is v2v not much of a concern because we are degreeing to the manufacturer's specs and thus if there was a v2v problem those specs wouldn't work for them either? That assumption however also assumes you're using the same valves that the manufacturer tested with and so on...

As it relates to my setup I happen to also be working on a b18c (US GSR version) similar to worked example, though I'm not sure if the worked example is the same as mine or the Type-R head + valves which are a little different.

Also that said, out of curiosity the further your setup deviates from the a stock setup (different valves, CR etc...) how relevant is it still to start out degreeing your cams to manufacturer's spec vs just degree-ing them in concert with tuning on the dyno from stock centerlines?

Hello v2v isnt really an issue when cam timing is close to the cam builders spec at all I've never seen any issue with this but care must be taken when fitting the cams to ensure v2v is not compromised. i always try and have the base cam timing set before the dyno where possible and fine-tuned on the dyno

I've only really seen valve to valve clearance issues when working with highly tuned motorcycle engines as their rev range can be be north of 16,000rpm; combine this with oversize valves, narrow stem diameters, big valve overlap, high lift cams and the fact that they're almost always direct acting cam over follower type it V2V contact becomes inevitable at some point in the development process. in the case of your application as Ross says i wouldn't expect it to be an issue assuming that everything has been built to spec properly.