roller rockers

[mountaineerjeff]

I've seen all the threads on rockers and they all kinda end the same way. Mostly inconclusively....I'm looking into running 1.7 ratio rockers, but have been told that there is an issue making them work in the 4.0 head. Has anyone ran 1.7 rockers in a stock head?

[SilverXJ]

I don't know who says they won't work but I know of several people running 1.7:1 ratios on stock heads.

[I6FAN]

I think YellaTerra actually makes a 1.7 ratio as well as the stock 1.6.

[jeepxj3]

I tried and can't find any YT 1.7 RR available for sale. Does anyone have a source?

[CandyCaneXj]

Anyone know if the renix valve springs can handle the same lift as the ho valve springs?

[mountaineerjeff]

I just tried to order a set from Harland Sharp and I was too that the angle caused by the ratio change can cause the push rods to contact the head. But I have never heard of this, and the rep had not seen it first hand...so here we are.

[SilverXJ]

Ahh.. that is understandable considering that the pushrod side is probably shortened to accomplish the ratio change. If this happens it would be simply a matter of removing a bit of material from the head. There is enough to remove, however you would need to pull the head. I have never heard of anyone having these issues though. It will also depend on the camshaft as well.. higher lift will pull the pushrod closer to the driver side of the head.

[mountaineerjeff]

Well I was hoping to find someone with first hand experience running them on a stock cam...I'd hate to buy em and not use em...cause if I pull my head, I'm doing pistons and a hesco head. And I really am not trying to spend that much right this sec.

[SilverXJ]

I don't see a problem with the 1.7 rockers on a stock cam. In fact the majority of the 1.7s are on a stock cam just because its an upgrade that requires little unbolting.

[mountaineerjeff]

That's what I thought, but then why would the rep try and talk me out of them? Doesn't make any sense.

[jeepxj3]

Does HS make a set of 1.7 for the 4.0? Part Number?

[mountaineerjeff]

They dont have a part number. I called them directly to get them to make me a set and they recommended I research the subject before buying something that won't fit.

[CandyCaneXj]

I talked to them a few months ago the guy said he could make any ratio you wanted but he was convinced anything over 1.6 would require head work. They wanted $550 for a set of 1.65 ratios

[mountaineerjeff]

That's been my exact same experience. I was totally all for paying for a set, but not if they aren't gonna fit/work.

[SilverXJ]

Worse case you pull the head and do some grinding on the pushrod holes.