Evo cam in shovel with VT lifters

[dbdevkc]

Let's say I have the Velva Touch evo blocks and lifters - what would be a good, reasonable cam to run? VT has suggested the Andrews EV27. Also, how much case clearancing is needed for that cam?

[dbdevkc]

Ok, so here are the choices and options I have. Before I get into it, I gotta say both David from Velva Touch and Scott from Hillside Cycles were very generous with their time and expertise. They both took time out of their day to walk me through their thoughts and suggestions.

The Velva Touch lifters/blocks/rods are essentially the originals, improvements have been made since then. I can have David at VT re-work them to bring them up to his current standards. Or for less money then that will take, trade up to a brand new set of shovel/evo VTs.

If I trade up, that will mean changing the cam to an evo. David recommended the Andrews EV27. Of course that also means doing something about the current stock rockers that I have. Possibly swapping to evo rollers.

Spoke with Scott at Hillside - they will be doing my heads - and he suggested sticking with the shovel rollers on the lifters and using an Andrews 2 cam. He said he thought the compression would need to be higher to take full advantage of the EV27 - but he also said he would defer to the VT recommendation. For reference, I have Wisco .040 over pistons, which according to their documentation are 9:1.

So options are:
1) Stick with shovel velva touch, Andrews #2 cam, S&S or Jims shovel roller rockers
2) Shovel/evo Velva Touch, Andrews EV27 cam, evo roller rockers

Both options, the case will need some clearancing for the cam. For the second option the rocker spacer will need to be modified.

I'd love to get some opinions on these choices.

Thanks!

[Ohio HD]

I would follow Scott's advice. As well I've used the #2 in several small stroker Shovels. It's a good cam, gives a wide power band, mostly noticeable in the mid range. I'd keep the Shovel all Shovel. Just my 2 cents.

I don't remember having to clearance the cases for a #2 cam. They have a smaller base circle so the lobe maximum dimensions should fit just fine in the case clearance pocket below the cam bearing. If for some reason it does need clearance, a small Dremel style bit can be used to slowly open the area. You want a minimum of 0.030" clearance. ADDED: Also check above the bearing for clearance of course.

Roller rockers for the #2 cams is optional in my opinion. 

[JW113]

I just did Option 2 to my Shovel, using Jims Powerglide tappets, blocks, & pushrods, and S&S roller rockers. And yes, took Scott's advice about the Andrews 2 cam. The Andrews lit says it is intended for low compression engines like 7-7.5, so I called them and asked about the 8.5:1 pistons that I'm using. Was told no problem, just make sure you use premium gas and not an overly aggressive ignition timing curve at the lower rpms. Which, I'm using an Ultima Single Fire system with VOES. So far, it is quite impressive, massive torque in the midrange. So much so the stock clutch was slipping at full throttle, so I upgraded to the AMS (Pro clutch) diaphragm type, which is holding the torque great. I think if you follow Scott's advice, you can't go wrong.

-JW

[dbdevkc]

The Andrews lit says it is intended for low compression engines like 7-7.5, so I called them and asked about the 8.5:1 pistons that I'm using. Was told no problem, just make sure you use premium gas and not an overly aggressive ignition timing curve at the lower rpms.

That is what has me stuck for the moment on which way to go. The Wiseco pistons that I have are listed as 9:1 in this 74". 9:1 might be too high for the #2 cam, I don't know.


And if I go to the Evo Velva Touch (and Evo rockers), and go with the EV27 cam, 9:1 might be a little low for that. I think I'd rather not cut stuff down to increase the compression partly because it is a kick only bike. I could add compression releases if I go that route, but I feel like I am starting to go down a rabbit hole for no good reason.

But... it is going to cost more to update my existing shovel Velva Touch lifters/blocks/rods than it would be to update to VT evo config (getting a sweet deal if I choose that route).

I'd probably be happy with it either way, but man the decision.

[Ohio HD]

Why do you think you need to replace the lifters at all?

What you probably have is the original Velva Touch made and designed by Vern Ott (VMO) right here in Ohio. The owner (BMO) now is not the same guy, and I'm sure doesn't use the same hydraulic components that were once used.


Vern Ott ~ VMO Velva Touch

[dbdevkc]

Yes, mine are originals. But they had been sent to B-M-O and he stated they need some work to address some issues and bring them up to current standards...

[JW113]

I thought you had an Andrews A? That should work nicely with 9:1. The 2 may also, ask Andrews about it. Although if you compare timing between the 2 and EV27, they are not all that different. The A is closer (comparatively speaking) to an EV46. I have a Crane FB-3002B (like an EV-13) in my Evo, which as 9.5:1, and less duration and sooner intake closing than the Andrews 2, and it's no problem at all.

-JW

[dbdevkc]

Do have an A. Scott suggested a 2 would be a nice bump for it. But hearing what Andrews told you about 8.5:1, I figured 9:1 would cause even more caveats.

[dbdevkc]

I just fired off a "contact us" note to Andrews tech support and will see what they have to say.