Thread: Williams Helical Camshaft for SR type engines.

No aftermarket camshaft is going to comply with emmission laws, full stop.
Emmission laws are directed at car manufacturers and the car manufacturer are only liable to comply with those laws whilst the car is used as a " factory equipped"
A lot of aftermarket and performance parts are normally sold with the understanding that it is intended for motorsport and wont necessary meet local authorities standards.
Once the owner of that car go and modify it, it is up to the local traffic authority to ensure that it polices the owners and users by means of various emissions tests.
I still dont see the issue with having these cams developed for the VE head, as if you do go that route, it would be a single lobe per cyl as the HC will take care of the duration and timing events.
I have seen a VE head with some major changes where only one lobe is used with a killer camshaft due to the superior flow capacity over a DE cyl head.
We all know that the VE have a superior valve train over the DE and are limited by max Rpm's to cam profile design, ramp angle etc.
I am still willing to borrow you guys a VE cyl head.
Gerry

Kiwi - thank you for your information which is very helpful.
From what you say a VE head could fitted with with DE cams and valve gear. From what other people were saying I thought that this was not possible.
If it is possible it would mean that a variable cam developed for a DE would fit a VE anyhow.
Remember that, at present, we have very little first-hand knowledge of SR engines at all.
We are very wary of becoming involved in a big (and expensive) project - and an SR project would be just that. We have all ready spent a lot of money on three prototypes that were demonstrated to run perfectly well which resulted in basically absolutely no profit to us. We really don't want this to happen again.
We are starting to think that the manufacture and marketing of a simple two-lobe Type 1 cam-and-controller for a single cylinder motorbike engine may be the best option. If this works out maybe we can progress to more ambitious projects like SRs or whatever.

Which follower does the single lobe actuate? The center follower, or the side two followers? If you're talking about the center follower, something must be done to lock it into active mode (instead of passive mode) 100% of the time instead of activated by oil pressure.

You sure it was one lobe (the center lobe)? You sure it wasn't two side lobes?

It was using the 2 outside lobes and the centre lobe was grinded away, however there is the possibility to lock the mechanism mechanically and use the 1 centre lobe if needed.
I am not saying this will work without fail but maybe worth the while investigating the possibility

Isn't the point whether the DE cams and DE type of rockers can be fitted to a VE head without machining etc.? That's what I want to know.

Not without any machining. DE uses a hydraulic lifter on the non Roller rocker and the VE and later SR DE's using a roller rocker.
When Reg Cook ( Cook Motorsport in New Zealand ) used a VE head years back for his project drag GTI-R there were no aftermarket camshaft suppliers for the VE. He chose to use the VE cyl head due to the superior flow capabilities and valvetrain reliability.
He used a DE camshaft for his build and had some tricky engineering and machining done in order to make this all work.
Where I see this all now is as follows.
When using a VE head, there is no need for a secondary lobe, eliminating high lift as I believe with the patented HC cam there is no need for it.
If the HC cam will work in a DE it will work in a VE head provided that there is no secondary lobe. Wether you eliminate the outer lobes and lock the device to run from the centre high lobe or remove the centre lobe depends on how much room you need to make the device work
The same cam or billet wont work in both as the cam journals of the 2 are not the same nor will the rocker ratios be the same.
You can not use the DE rockers in a VE and vice versa.
I think the only way you will know is if you inspect a VE head.
My offer still stand to freight a head out to you when I have it availble
Gerry

dont take this the wrong way, but this does not surprise me considering the 3 engines you decided to use

Bluebird - it was not taken the wrong way. It is just that those three engines were the most suitable for building the various prototypes - but clearly they were not the best commercial choices.
We thought that we would only have to demonstrate that the variable cam principles worked well to have car manufacturers falling over themselves to give us money but it didn't (or hasn't yet) happened.

Have a look at this computer animation of the HC which has just appeared on the internet:
YouTube - Helical camshaft

We have no idea who made it but they certainly have a lot more computer skills than us.

I probably should point out that although this animation shows the principle very nicely it is slightly misleading. The overall lobe shape is a bit unnatural and distorted and, possibly more important, the lobe rotates in the wrong direction. The intention is that the "solid" (stronger) part of the lobe contacts the follower first.