[Chris-Austria]

Hi,

if I want 1.65 rockers for my E-heads, will I need to work on the pushrod holes?
If so, can I do this with the heads still installed? Maybe remove the valley pan, remove the lifters and seal up everything?

Total lift would be at about .60"

Thanks!
Chris

[steve25]

The holes should be plenty big as they are unless your running bigger diameter push rods then 3/8”?

Note that the as shipped push rod guide plates are made for 5/16” push rods anyway, plus the angle that can make for clearance issues changes with the lifters used.
Roller lifters are mostly taller then flat tapet lifters which can make for less of a angle .

[Formulas]

My early second head bolt design E'heads needed clearance with 5/16 pushrods and Harlan Sharp 1.65s. By at least .040 .630 ish lift

Hopefully subsequent designs they moved the holes because its makes NO sense to have a 1/2 inch hole in the spot they put it

[Skip Fix]

Originally Posted by Formulas

My early second head bolt design E'heads needed clearance with 5/16 pushrods and Harlan Sharp 1.65s. By at least .040 .630 ish lift

Hopefully subsequent designs they moved the holes because its makes NO sense to have a 1/2 inch hole in the spot they put it

Same on my E heads both sets early versions.

[64speed]

My e heads have 1.7 bbc rockers no problem

[Chris-Austria]

I have 5/16" pushrods from Butler (8.800x.116x5/16").
The E-heads are from maybe 2015 or so, not sure if these are considered "early".

I also have HR lifters, so maybe I could use 1.65 rockers without modification?
But if I order a set and it will not clear, can I clear them with the heads still installed?

By the way... which rockers should I choose? I always had the Scorpion Race 1.5 full roller and they seem to work very well.
There are the gold Comps (why so expensive??) or Scorpion Race 1.65, Harland... or the PRW stainless steel rockers. Is stainless steel or aluminium the better choice?

[67Fbird]

depends on your choice of material removal. YES you need to tape off/seal off as much as you can. A shop vac and rat tail file works well. NOW if you get indo using a die grinder and burr.....you are going to have a big mess. also note the CLEANER things are before starting...the better chance you have of success as ANY oil residue is like a magnet for shavings!

[78w72]

following for confirmation on 5/16 push rods with 1.65 H/S rockers. OF cam with comp "S" HR lifters.

are 60599 E-heads after about 2010 considered "later" style?

[nas t eh]

Originally Posted by Chris-Austria

By the way... which rockers should I choose? I always had the Scorpion Race 1.5 full roller and they seem to work very well.
There are the gold Comps (why so expensive??) or Scorpion Race 1.65, Harland... or the PRW stainless steel rockers. Is stainless steel or aluminium the better choice?

I got PRW SS roller from Butler a few years back. But I've since read that PRW and many of the other cheap brands should be avoided. It's the only thing that I bought from Butler that I regret. I haven't ran the motor much, they will be replaced before I do.

From what I've read regarding roller rockers, Crower, HS and Comp gold are the only ones to buy for street use.

[pastry_chef]

Originally Posted by Chris-Austria

By the way... which rockers should I choose? I always had the Scorpion Race 1.5 full roller and they seem to work very well.
There are the gold Comps (why so expensive??) or Scorpion Race 1.65, Harland... or the PRW stainless steel rockers. Is stainless steel or aluminium the better choice?

For aluminum .. Harland Sharp.

Stainless - Crower, but expensive.

[steve25]

If the heads have not had the push rod bulge ground back then the rework will go a lot faster and make less of a mess if you just drill out the push rod holes with a 1/2” bit.

The question I want to ask the OP is are your heads ported and what is the details of the Cam your are running?

If the heads are stock I do not think that the cost and effort to put on 1.65 rockers is worth the amount of power gain, especially if the intake manifold being run is the choke point as compared to what the heads flow now.

[Chris-Austria]

Originally Posted by steve25

If the heads have not had the push rod bulge ground back then the rework will go a lot faster and make less of a mess if you just drill out the push rod holes with a 1/2” bit.

The question I want to ask the OP is are your heads ported and what is the details of the Cam your are running?

If the heads are stock I do not think that the cost and effort to put on 1.65 rockers is worth the amount of power gain, especially if the intake manifold being run is the choke point as compared to what the heads flow now.

I was also wondering if it's worth the effort... heads are not ported, standard Eheads (d-port). The cam is a HR 236/242/114 from Butler, intake is a RPM (gasket matched) and I use a Sniper EFI with about 1" spacer.

I think it's only worth the money if I can easily swap them, but if I decide to do so and they don't clear, I need a plan b I could remove the valvetrain components, clean and seal everything, but thats a lot of work if there is just a very small power gain.

[78w72]

i dont know & am curious, but wouldnt .15 increase in lift & duration be like stepping up to a bigger cam? if the heads & intake can support the extra lift shouldnt that be worth some decent power?

i have the OF cam that is similar to yours in a 467, i recall that the .575ish lift went to .600+ & added a couple or 3 degrees of duration with 1.65 rockers vs 1.5.

[steve25]

.575” lift with 1.5 rockers is .383” lobe lift, replacing the 1.50 rockers with 1.65 rockers takes the lift up to .631”and will add close 4 more degrees to the duration on the nose of the Cam.
Added power may or may not be had if the exh to intake ratio is shifted away from what’s needed by the combo.

[nas t eh]

You will need to ensure the spring package can support the extra lift or plan to change the springs.
I got complete ported 290cfm D port heads from Butler as well as the cam, lifters, pushrods, rockers. The plan was 1.5 ratio all along and a big enough cam for my combo. I was told and a note was put in the box of parts that 1.65 ratio rockers we not an option down the road. IIRC it's the currently supplied springs that won't support the extra lift. But as has also been pointed out by others here, my intake and exhaust would not be big enough either.
I went solid roller and my lift is ~0.580 as well.

[78w72]

Originally Posted by nas t eh

You will need to ensure the spring package can support the extra lift or plan to change the springs.
I got complete ported 290cfm D port heads from Butler as well as the cam, lifters, pushrods, rockers. The plan was 1.5 ratio all along and a big enough cam for my combo. I was told and a note was put in the box of parts that 1.65 ratio rockers we not an option down the road. IIRC it's the currently supplied springs that won't support the extra lift. But as has also been pointed out by others here, my intake and exhaust would not be big enough either.
I went solid roller and my lift is ~0.580 as well.

SD said the springs they supplied with the OF cam would be ok to use 1.65 rockers. i will leave the 1.5's until if/when the heads come of for porting, just curious if 1.65 would work with the stock E-heads.

[Chris-Austria]

my valve springs would be fine with the 1.65 rockers

the valve lift now is 0.521 and 0.540 with 1.5 rockers, so with 1.65 it will be 0.573 and 0.594

the springs have a installed height of 1.800 and coil bind height 1.150... so the calculation would be 1.800 - 1.150 - 0.050 = 0.600 (max valve lift)
they have a closed pressure of 150 and open pressure of 420

the biggest question would be, if it is really just a simple swap (no drilling) and if it will be good for performance

[Formulas]

D'port aluminum E'heads would not be considered early
Just a guess but you should be good, high volume engine builders should be able to confirm

Another possibility is order a single 1.65 mock it up if they work order set of 16 have a spare if not order 1.5's

[Chris-Austria]

when changing from 1.5 to 1.65 ratio, which direction will the pushrod travel?
closer to the intake side or closer to the exhaust side?

thats how it looks with my 1.5 ratio rockers



if they would come closer to the rocker stud, I may be fine since it looks like they are a little off center into the other direction

[Formulas]

Towards the stud, That distance is less with a higher ratio, same brand / design and its ABOUT .050 in that range
You look to have generous clearance with 1.5 and that particular rocker
1 caveat is if you go a different brand rocker the distances from stud on both sides could be slightly different