Largest cam using Type 4/5 lifters

[Steve C]

Hi

I tried searching but I cant seem to find the information I need.

I'm considering building up an Oxyboxer, at what point in performance cams do the stock style Type 4/5 lifters become unusable and Type 1 lifters need to be used?

Steve

[tencentlife]

That's actually a really good question. I don't think you could come up with a number, maybe a vague range is the best you could do, since advertised duration and duration at .050" still don't describe the shape of the lobes on any particular cam. The way I've done it is to throw down and buy the cam I want to try, and lay it up in a case with some lifters and look closely at how the lobe and lifter face make contact. As long as the edge of the lifter face never touches the lobe, then that cam should work. But the cams I've tried have pretty short-to-moderate duration, obviously as duration goes up, and/or the more aggressive the lobe ramps are, the closer the cam comes to making contact across the edge. No matter how much you can learn abstractly or thru others, this is a test you must do once you have the parts in hand anyway.

[buildabiggerboxer]

further down the page you will see my pic of a 120 on a wasser lifter, some claim to have run these with no problems, but i say they're on the absolute limit, and very close to edge loading,
a ratio cam would be better, i would say an FK10 would be o.k. on the stock size lifter, not hydraulic though. one thing i do, is gut and mod the hydro lifter with a tubular insert, makes a lighter and better lifter than the heavy T4 solid ones, plus you retain the better lifter oil channels.

[tencentlife]

I should amend my remarks here a little bit, since I've been dealing with this again just this week: it's not so much that the lobe can't touch the edge of the lifter at all, it's more that it isn't attacking the edge at an angle, i.e. part of the lobe should be bearing flat against the face of the lifter even though the remainder of the lobe extends past the edge of the lifter face. Hard to describe, actually, I should try to take some pics to illustrate.

Yes, I would think a W120 might go a little too far, just knowing the numbers. I don't understand where your pic is supposed to be, bbb.

Definitely, small-lift lobes intended for use with ratio rockers would have a much better chance of avoiding edge interference.

Yeah, I always assumed plain T4 lifters must be lighter until I weighed them against some hydros. The solids are a lot heavier!

[buildabiggerboxer]

Cant find it either! Quicker to post it up again, Engle 120/T4 lifter. hhhmmm. hope it helps.

[Steve C]

Hi

Thanks for the replies.

I've started buying the bits I need, bought a 2.1 case already cut down from a friend and a 88 stroker so I'm going 88 x 94.

The guy a got the case from is an Aussie drag racer Rod Penrose who often visits the US buying parts, some of you may have met him. He has offered me Type 4 Scat lifters with centre lube hole, are these any good?

Do the lifter bores need to be sunk down when using a largish cam? Still weighing up my options but I'm thinking K8 or 86C.

I built a mild 1904 on a mag case and now I want more, so I will slowly collect the parts and then build it up.

Steve

[fastback]

even a TCS-10 with type 4 std diameter lifter is in the doubtful area.
which is a W110 intake and W100 exhaust
mine went down quickly.
if u look at CB they have a couple of high-rev cams 2253 and 2254, that are grinded for hydraulic/small diameter lifters.
or convert to type 1 lifters
or buy the "big-foot" lifters and run large cams.

[buildabiggerboxer]

Steve, I'm sure you're clued up already, but an 88 crank will need all T4 mains with chevy b/e journals, with a serious build like that i would bush the lifters and go either T1, or have a look at europeans lightweight lifter and bush kits, T4 solids are very heavy, as we said above,
better to modify the hydros to solid.

[Steve C]

Hi

Thanks for all the info guys.

The crank I have bought is a 88 DLR WBX crank with Chevy journals and 200 mm flwheel, it was on TheSamba recently for sale.

I had a DJ (10.5:1 comp) 2.1 Wasserboxer in a Superbug in 1988, I ran it with IDAs, 110 Engle with Rhoads lifters and 1.4 rockers, I then later went to EFI & turbo with 8:1 comp

I have sold that car and I'm building another bug with 2 litre WRX STI motor with a G50, the Oxy boxer will go in another bug I have, my daily/sons car. We use this car for amateur track work, just having fun or going to the shops.

Steve

The daily

[fastback]

any more info on those rhoads lifters??

[Steve C]

Hi

I bought them along with the cam from Gene Berg, they worked fine although I didn't do any back to back comparison.

You can get more info about them here http://www.rhoadslifters.com/

Steve

[fastback]

thx. i tried the website yesterday and it was down, but today , another story

i asume these are stock type4/wbx diameter??

[Steve C]

Hi

They were a direct replacement for the stock lifters, forgot to say they make a slight ticking sound.

Steve