Valve regrind

[phaetn]

I have two heads at a machinist's so he can mix and match best bits to install new valve guides and cut new valve seats.

Along with the spare head are attached cam towers and cam shafts. I basically have two sets of everything except cam covers and a missing exhaust cam pulley. This got me thinking.

Is there any point in asking the machinist to grind one of the sets of cams to a performance profile? Even if the shafts lose meat off the lobes because of the regrind I have lots of spare thicker shims or he could mill the bottom of the cam boxes to compensate to get the right lash.

I could have one stock original set and another mild performance set with more duration/overlap.

Does this make sense?

I already have a free flowing exhaust, a big enough carb, and great ignition. I also have a set of performance Isky spings. I'm not ready for domed high compression pistons, but maybe could go for variable cam pulleys.

Or maybe I should wait and order bigger valves to get a multi-angle cut into the spare head and do it all then... maybe for future years...

Thanks for any advice.

Cheers,
phaetn

[kmead]

I can't imagine that a locally recut cam would last or have an appropriate profile but then maybe the shop is very good. My biggest worry would be the hardening process for the face of the cam wear surfaces and if they would be able to harden those faces to the same level as the factory did.

Adjustable cam wheels will only be needed once you go for all the goodies, hot cams in particular, as you work to maximize the performance of the engine. Not really needed at all with stock parts.

[klweimer]

I think it would be hard to compete with the cam prices from our suppliers to do it yourself. And they have proven profiles to work from. Without higher compression pistons, I don't see too much value in going crazy on cam profiles anyway, I'd stick with something in the mild to moderate street range. You might also be able to put a multi-angle cut on the stock valves and seats, which could improve your head flow. I'd ask your machinist.

Adjustable cam wheels aren't required, but would help you get everything you can out of your engine. And they look cool. Check with your supplier on these to see what aux shaft pulley you need. I had to change mine to get the correct flange for the flange on the cam wheel.

Let us know what you decide!

Kirk

[phaetn]

Thanks, gents. I was only thinking of a streetable cam profile as it's a daily driver three seasons of the year. Nothing too lumpy. I'm already more than happy with WOT and highway passing from 3500+ rpm, so I was thinking more about a profile for low end torque, so not a lot of overlap.

I was wondering about the cost to do things locally versus getting cams from one of our great suppliers -- there's always extra cost for me for Stateside parts since I'm in Canada. I was also wondering about the capabilities of the local machinist. Those were all midnight musings.

i spoke to the machinist in the fresh light of day this morning and he said he doesn't regrind cams -- he'd have to send them out to another city. Plus they would need a template to follow so that's right out.

He did confirm, however, that he will do a multi angle grind (30, 45, 60) for the valve seats which I've read can add up to 10bhp even on a 1.8L motor with no other mods (see second chart for flow bench test). That's great news!

What makes me even happier is that I explained the benefits of a multi angle cut to my ten year old daughter who lapped it up (excuse the pun) with a smile on her face, and then explained it all back to her mother who had a bemused, knowing grin.

I have to get that girl racing go-karts — she passes everyone at the local fun track and she's got a serious need for speed! I asked her if she wanted to race and she said, "I wouldn't want to do it unless I could win." That's exactly the racing spirit!

Today I think a cottage neighbour is going to take her out on his JetSki. Woot! I have to keep her adrenaline going to make her happy.

Cheers,
phaetn