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Wally wrote:Nice pictures!
Yeah, I see your point but....the type 4/wbx lifter on the right bottom would run for about 500 miles before the cam would be toast...
What I am trying to say is that the second picture isn't allowed in reality. If your cam is so wild that it gripes the outer edges, you're screwed!
That is also one of the reasons that Webcam strongly advises to run type 1 lifters on their longest duration cams. Its even on their website.

Therefore, I still very strongly believe that it doesn't make a difference in real life - surviving - combinations.
Of course, you may not agree

I'm always on the fence-post as to whether pursue petty arguments...here goes:

(from Mr.Gasket's website)



So, as the equation states, the maximum velocity of the lifter (lifter displacement per degree of camshaft rotation, using a hypothetical cam-shaft) is directly proportional to the diameter of the face of the lifter. Again, for a given cam profile, a larger lifter face will result in greater duration @0.050" lift. Quick calculations suggest that a T4/WBX lifter will yield about 6 degrees less duration (@ 0.050") than a T1 lifter.

So, what I'm trying to say is who cares if my illustration depicts an "unrealistic" scenario with respect to the lobe shape and the edge of the lifter. I used bloody PowerPoint to make the illustration and didn't care to design the most realistic cam profile. Do the math...hell, just spend a few more minutes THINKING about the problem. The problem is, even with a mild cam, lifter size affects the valve events. If you're fine with that, pick a cam that compensates for the duration you'll lose with smaller lifters, or run a given cam knowing that the duration will be a bit less. That's the point.

Mmm.. type 1 lifters might be too much hassle.. unless I can find a reputable engineer to make the changes.. I dont have the facilities to do that. I shall have to see who can do that work.. Ceramic type 4's drop right in.... the rollers are not available...!!!

Nice point about the lobe/lifter relationship, but please, I didnt want to start any arguments..
About 1 deg difference? so is it then so much of a problem for a very mild upgrade of the cam. if I gain a lot more than stock and lose a tiny bit cause of the lifter.. I will still gain! But I need to do it reliably

So it comes to what cam can anyone suggest with either lifter?
I see Aircooled net has a type 4 hydraulic grind for torque, but that wont work in the wbx, but maybe they could grind a wbx one with the same principals.. ?

Maybe I should try the cam I thought anyway, if it doesnt work for my syncro, then put the engine in my 2wd, where more mid and top end will be welcome..

51MAN wrote: About 1 deg difference?

Or as much as:

Stripped66 wrote: Quick calculations suggest that a T4/WBX lifter will yield about 6 degrees less duration (@ 0.050") than a T1 lifter.

51MAN wrote: Maybe I should try the cam I thought anyway, if it doesnt work for my syncro, then put the engine in my 2wd, where more mid and top end will be welcome..

Probably the best choice.

Sorry miss read your reply..
6 deg, ok, still not a huge amount to lose if there is a gain over stock...

Trouble is I have no idea what a DG cam spec is, for comparison.

It will be a suck it and see then.. worst case is it doesnt work and I have to swap the cam out

Stripped66 wrote:

Wally wrote:

Stripped66 wrote: . The face of the T1 lifter is much larger than a WBX or T4 lifter; if you use a WBX or T4 lifter, your effective duration is going to be much lower than what the cam is advertised as.

Is this really true? I thought it didn't matter

A picture is worth 1000 words.



In a nutshell, advirtised duration may remain unchanged, but duration at 0.050" will be greater with a mushroom lifter (Type 1) than a flat tappet (Type 4 or WBX).

I agree !
If you use hi-lift cams you need the T1 lifters..

51MAN wrote: I have seen heard of wbx being run on engle 110/120's, even with the stock hydro lifters, is that disaster waiting to happen?

YES!

This is a W100 cam used with T4 solid lifters for about 1000 km. in a WBX.
The engine blew up by throwing a pushrod through the top of the engine

This engine made a terrible noise form the cam. It had good performance, but the cam noise was too much !

I believe the cam wear is caused by the edge of the solid T4 lifter !

As showed on Stripped66 nice drawing

Look out for NSFW popups from the above lifter cam damage pic links.

You can tell Web that the cam is for T4 lifters, they MAY be able to make it on a smaller base circle.
(They have T4 versions of many common profiles)

Your lift/duration at the valve will end up a bit different on the smaller BC.

The effective diameter of the lifter isn't the actual, it is what is actually swept by the cam.
Once beyond that point, it could be the diameter of a dinner plate and not make a difference to the calculations..


You have to miss the corners of the lifter, they are almost diamond hard, and as brittle.
(cams should have the edges taken off for the same reason unless you want the chips floating around, Web (usually) does this for you)