Rocker arm Mods for a Higher Ratio

[spmdr]

One thing that Really Needs to happen

for Any Performance application of an Alpine

engine is a change to Higher Ratio Rocker Arms.

I have been dragging my feet on this subject

for Way too long.

My Plan A is to Modify the Stock/original Rockers.

Instead of reinventing the wheel,

I assume Someone has "Been there, Done that"

If that Someone is YOU, please Do Tell.

DW

 

[260Alpine]

I've not done it but on the Volvo rockers for the Rover V8 they offset bore larger towards the adjuster then bush back to size to go from 1.45 to 1.6.

 

[Barry]

I've not done it but on the Volvo rockers for the Rover V8 they offset bore larger towards the adjuster then bush back to size to go from 1.45 to 1.6.

Offsetting the rocker arm bore will also offset the contact point of the rocker arm tip on the valve stem.

 

[alpine_64]

One thing that Really Needs to happen

for Any Performance application of an Alpine

engine is a change to Higher Ratio Rocker Arms.

I have been dragging my feet on this subject

for Way too long.

My Plan A is to Modify the Stock/original Rockers.

Instead of reinventing the wheel,

I assume Someone has "Been there, Done that"

If that Someone is YOU, please Do Tell.

DW

DW. Harland sharp offers the bigger ratio roller rockers for the alpine.

 

[Barry]

DW. Harland sharp offers the bigger ratio roller rockers for the alpine.

Another potential source:

https://www.classiccarperformance.com/products/sunbeam-alpine-performance-roller-rocker-set?_pos=5&_sid=6c6505efb&_ss=r

 

[spmdr]

I have considered the HS rockers, and May still buy a set...

BUT the price AND availability don't sit well with me.

Also, I have a PILE of V8 higher ratio Roller rockers that I Own...

However, adapting those V8 rockers would be a job.

And, I'm waiting for the comment that Alpine engines don't

NEED higher ratio rockers, because the port flow increase

STOPS at about .400"....

This is true for a Stock head. BUT it is also the stumbling block

that NEEDS to be overcome.

So, what to do...

Research.

I started the research and about 1/2 way thru, I started this post...

THEN, I found out about:

Performance Rocker Arms

Performance High performance rocker arms 25 years experienced employee owned.

www.rockerarms.com

I sent an email, ....crickets, so far...

My working plan A is to slot/relocate the mounting holes

in the pedestals/shafts and recontour the rocker tips

for an initial test set.

DW

 

[spmdr]

update, I Did Call Performance Rocker Arms

and they Did get my email and have started looking

into the project With Their ON the shelf Alpine rockers!

They suggested more info/a game plan next week.

One thing they are looking into is fitting other rockers,

sounds hopeful.

DW

 

[alpine_64]

Another potential source:

https://www.classiccarperformance.com/products/sunbeam-alpine-performance-roller-rocker-set?_pos=5&_sid=6c6505efb&_ss=r

They are probably the HS ones.. the HS were originally sold through a race prep shop.. they also wer selling beehive valve springs and titanium retainers

 

[alpine_64]

update, I Did Call Performance Rocker Arms

and they Did get my email and have started looking

into the project With Their ON the shelf Alpine rockers!

They suggested more info/a game plan next week.

One thing they are looking into is fitting other rockers,

sounds hopeful.

DW

Sent you an email

 

[alpine_64]

Ok.. so interestingly enough I was doing a search and

TRE performance has these listed.

Harland Sharp SunBeam Roller Rockers

Harland Sharp SunBeam Roller Rockers

treperformance.com

Note the 1.4 or 1.5 ratio... And they are apparently hardland sharp.
Iirc the 1.4 measured at 1.36:1 when someone first got them..less than stock.. and 1.5 isn't much improvement..1.6 was the more interesting spec.

I know they modified them design at some point.

Here is a photo of mine which are form 2012 iirc..


The ones on the tre site are a different design..the more typical stock HS style.. so is the website photo a "indicative" ...or are these what they look like.. they don't appear to have the offset

 

[Shannon Boal]

I like the roller part of the rocker a lot. It should lower the sideways load on the valve-stem and in so doing reduce the valve guide wear. Also, your higher ratio rocker gives faster action to the valves increasing the area under the lift vs time curve. So.....more airflow in the confines of that maximum flow 0.400" lift limit. I remember Brian's World's Fastest Alpine used a Roller Cam, titanium 240Z valves and......roller rockers?

 

[alpine_64]

I like the roller part of the rocker a lot. It should lower the sideways load on the valve-stem and in so doing reduce the valve guide wear. Also, your higher ratio rocker gives faster action to the valves increasing the area under the lift vs time curve. So.....more airflow in the confines of that maximum flow 0.400" lift limit. I remember Brian's World's Fastest Alpine used a Roller Cam, titanium 240Z valves and......roller rockers?

Do you mean Brian's turbo alpine? He had his own roller rockers and a roller cam too. The dastun valves are a common performance mod.

If someone stateside could call the guys at TRE and ask if the photo on the site is the actual rockers or just a stock pic it would be good. I imagine they are stock as they don't have the offset of the others

 

[husky drvr]

If someone stateside could call the guys at TRE and ask if the photo on the site is the actual rockers or just a stock pic it would be good. I imagine they are stock as they don't have the offset of the others

Well, the add copy reads "shaft mount," but the picture is of rockers complete with a mounting trunnion.

Just a thought,

 

[alpine_64]

Well, the add copy reads "shaft mount," but the picture is of rockers complete with a mounting trunnion.

Just a thought,

I suspect it's just a stock pic of the usual HS design, but I do know the Alpine ones were redesigned after some earlier failures... Trying to do some digging

 

[spmdr]

I picked up a set of HS rockers here:

Harland Sharp Roller Rocker Arms

There are other threads dealing with roller rockers, Here is one: https://forum.sunbeamalpine.org/index.php?threads/roller-rockers-for-alpine-engines-not-v6.25062/ But I decided to start a new thread about the Harland Sharp rockers. The HS rockers for an Alpine are listed available from...

forum.sunbeamalpine.org

But they have their limits.

....and fitting challenges....

So I am still looking at moding a set of stock rockers.

However, I'm looking at as HIGH a ratio as possible.

Pushrod engines are on the endanger list,

as well as ICE in general.

BUT, of the current pushrod engines in

popular use, rockers ratios are going UP!

Chevy LS rockers are 1.8:1 +

And NASCAR engines are using 2:1 +

And there are at least 3 reasons to go

with a higher ratio.

1) Faster valve movement.

2) Higher valve lifts.

3) Better valve train control with softer valve springs.

DW

 

[spmdr]

I started the rocker ratio mod effort.


It's your basic "cut and try" effort...

I used a stock SV cam and stock valves.


I slotted the mounting pedestal hole

and put it together.


I find I over did it!




It's what happens when the pedestal

is backwards...

So here is the rocker shaft moved

as far away from the valve as possible,

without cutting into the shaft.



Here are marks showing the movement

of the contact point of the valve.




And the first effort of re-profiling

the rocker arm, JUST for proto effort.

I would Not attempt to run it with that

little contact surface.




Here is the closed valve mod rocker

contact point. 0 lash.




Here is max lift contact point.



So what did I gain?

NOT much/enough!!...


Plan A has NOT panned out...

I only changed the ratio

up to about 1.45

I really want a ratio of 1.6 I think...

to get there, I need to move the

valve side of the rocker way out.

And that would put the contact point

OFF the end of the rocker.


Plan B is to Offset the rocker arm

shaft hole.

BUT, THIS time I NEED to try IT

on paper first.

DW

 

[spmdr]

After thinking over Plan B,

I concluded It would be a

2 step process.


Step 1- Mod the Rocker pivot

location.

Step 2- Mod the location of

rocker shaft.

THAT is a lot of work.


My latest thoughts are a

revised Plan A.

With the advantage of reversed

rocker shaft pedestals, the only

thing needed is longer

rocker arms.

I restarted with STD rocker

pedestals and reversed them.



Then built up the end of the

rocker with the Mig welder.



I contoured the extended rocker

to put the new center over the

middle of the valve stem.



As it turns out, I ended up

with a New ratio of 1.585

Better lucky than good...



Now to make up a set with

better welding and give them

a try.

DW

 

[spmdr]

Thinking over the welding

possibilities, the end result

needs to be some decent

material.

Something with Nickel

And/or Hard faced.

THEN I got to thinking

What if I weld a large

needle Roller bearing

onto the arm?

...Gives a new meaning

to having Roller tip

Rockers (oh my!).

It also has the advantage

of being quick And consistent.


As near as I can tell,

the stock rocker has a

valve tip end radius of

about .345"

I'm Not holding my breath

with hopes of finding

that sized roller... ;-)

DW

 

[jdoclogan]

Your molecular mind thoughts are quite disturbing and intriguing. Go forth you creative wizard.

 

[Asm109]

Welding a chunk on the tip and drilling a hole for roller shaft puts a lot fewer material requirements on the welding than trying to get a good wear surface.
Also easier to get the shaft in the same location on all the rockers.
Go forth with confidence.
Oh, here is the page of drawn cup needle bearings from McMaster Carr.

McMaster-Carr

McMaster-Carr is the complete source for your plant with over 595,000 products. 98% of products ordered ship from stock and deliver same or next day.

www.mcmaster.com