3.4 + roller cam = no go???

[85maro]

I've read the oppinions and dissected a lifter looking for an awnser, but short of installing a roller cam in my current 2.8 and waiting for destruction I haven't found any concrete info on why a roller cam can't be used in a gen 1 block. There's no 'hole' under the roller for oil to 'puke out' and both roller and tappet lifters are the same diameter which means the only other exit is the rockers and I don't see roller fulcrum rockers needing substantially more oil than stamped. So has anyone installed or seen rollers installed in a gen 1 block and cause main, rod or lifter failure?

[1988GTU]

The best I can give for an answer is that someone once took a Gen two and made it into a roller style engine. They drilled some holes, made some threads, and used the 3x00 guide plates to make use of the later lifters to hold the lifters in position so they dont rotate. Then they put in a button through the t-cover to prevent walking of the cam since the flat tappet is ground on an angle to keep certain thrust specs in order with the roller cam.
The reason why people have not done this sorta thing to the 660 is the tight spacing and supposed weak cam valley area.

[34blazer]

the turbo buick guys are now installing hyd roller cams into the 3.8. i dont know what it takes but you could ask poston buick or weber racing what it takes to retrofit the cam into the engine.

[923.4v6]

Heres the thread I started when I was aiming to go roller http://60degreev6.com/forum/f96/roller-cam-t33219 but I backed out. If I were to go roller I would install a HV oil pump and on the sides of the lifters they have a intrusion around them, which helps let the oil go threw the vallies, I believe I would widen them out a little since it is a little norrower on the roller.

[geoffinbc]

There is no reason you cannot do it. You wont blow up your engine. But there are obstacles to overcome which usually persuade people to upgrade to a Gen III block or stick with a flat tappet cam.

You need to control cam thrust and also have some sort of anti rotation bars or guides. Gen III blocks have this all figured out. Gen I and II blocks have no provisions for either so your on your own. It would be nice if you could steal lifters from another engine but we have very narrow lifter spacing so there really is not much out there. You could buy retrofit roller lifters and then maybe make your own link bars. Then use a thrust button on the front of the cam to prevent any walking.

[85maro]

I already have my hybrid assembled, I'm just waiting for better weather to paint & install. I chamfered fwd antirotation bars & welded studs to the lifter valley to hold them down and a roller cam ground & drilled it for a roller chain. I have a standard pump in it now, but since it's going to peak at 6500rpm I'm rethinking that. What about the oil hole on the lifter body being exposed at high lift? If my measurements are correct it shouldn't be a problem below ~.6" valve lift (1.5 rockers). So by the sound of it I need to crack it open and put a hv pump & cam button in ('doh). I wanted to put a windage tray in anyway. Just looking for anything I might have overlooked before I fire it up.

[SappySE107]

You don't need a HV oil pump and it will just take away HP trying to pump more oil out.

[geoffinbc]

Agreed. The stock pump is PLENTY.

If you expose the lifter oil hole your going to have problems. Be sure you check.

[icemanspecops]

what year and what make of vehicle do I find a genIII block?

[icemanspecops]

tired 2.8

I've got an 86 4X4 S-15 Blazer with TBI 2.8. I like the 2.8 stroke but want more bore so thought that I would get a 3.4 block and over bore it. I want a to have a roller set up in it. I thought about putting in a destroked 3.4 DOHC. Anyone ever done this?

[pocket-rocket]

A long time ago, Ben had talked with me about wanting to do a destroked DOHC, but as far as I know, no one has done it.