[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.

[Chris-Austria]

you're right, I checked some that I can easily see and they all seem to look like on the picture... but I cannot confirm that for all 16
it's good to know, that they tend to point more towards the other direction, which will give more clearance after moving them towards the studs

I'm a little bit more willing risk it and just buy a complete set and hope for the best the heads flow charts show, that they flow about 270 at .060 and 258 or so at .050... I should have bought ported heads... but I don't want to remove them and send them in at the moment

[Steve C.]

"the heads flow charts show, that they flow about 270 at .060 and 258 or so at .050.."

?????

What part number Edelbrock heads are in use here ?

Flow numbers here:

https://www.edelbrock.com/cylinder-head-flow-data


.

[64speed]

My e heads have 1.7 bbc rockers no problem

[Chris-Austria]

I think its 61599… but I got the test results from Motortrend which seem to be a little different from the otter flow chart.. but they are pretty close

[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?

[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.

[Chris-Austria]

A general question when increasing valve lift with 1.65 rockers:

How can I know how much lift the valve springs support apart from calculating coil bind? (which will be fine with my combination)
Do I need a certain amount of spring pressure for lets say .594 valve lift?
My pistons have -15cc and block is not zero decked, so I guess the distance valve to piston shouldn't be a problem with less than .600 valve lift.
Heads are d-port Edelbrock with stainless valves that came with it.

Any other things I should check?

[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?

[Chris-Austria]

so the biggestet concern is coil bind, valves or other parts will not have trouble with more lift?

I think there are 6 coils so I would need to calculate 1.800 - 1.150 - 0.060 = 0.590
The max lift on the exhaust will be 0.594.

So I'm 0.004" closer than you say or 0.0007" at every coil. Springs are brand new, so I wouldn't like to change them again.... (Edelbrock 5845)

[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.

[Chris-Austria]

I was told that most times the total lift is a little less than what you would expect by using only "theoretical" specs in the calculator.. with .594 lift I'm still .056 away from coil bind, so using the numbers from your post I should be safe (as long as total lift is not more than lets say max .600

[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.