Roller Rockers Yella Terra

[Mr Haribo]

Hello All,
Has anyone fitted them and was there any upside's ?
I'm looking to change as I don't want the pad problem and will it allow the engine to rev harder or will the bottom end need more work for that to happen.
Many thanks

[vaurien]

4,6ltr. ... Merlin cylinder heads ... cross flow water system ... and a lot of other change

[Mr Haribo]

Nice what sort of power does that give ?

[Matthew Poxon]

Very nice!

[Pupp]

They are good gear - a tad heavier than the OEM rockers but eliminate the dreaded pad problems (do not underestimate the potential for this to kill engines), will facilitate higher RPMs where cam and head spec etc allow, and enable preloads to be set easily if hydraulic lifters are retained. Ideally, perhaps not run with the spring based spacing but I have for a couple of years with no issues at all. Complete no-brainer on any serious RV8

[Matthew Poxon]

Did you go for JE end posts as well when you upgraded to roller rockers Gary?

[Pupp]

Yes, Matthew, in fact I was using the billet end posts for a long time before doing the roller rockers due to the cam profile I use shoving the peaks further up the range

[Mr Haribo]

Is it worth doing the this set using the old ones




or full fat

[Matthew Poxon]

Full fat is around 1.5k iirc.



For 1.5k I think I would be looking at putting the money towards a set of TA or Wildcat heads complete with roller rockers.

[Hoofa]

I am using a full fat set of these , spot on apart from needing taller rocker covers , hmm 5 years of leaking rocker covers, tried most combination of gaskets goo etc.

So finally sourced a set of the tvr cast taller Tuscan style covers so we will see how these go, at least it will get rid of the spacers that you will need with these rockers

[Matthew Poxon]

Coincidentally just bought a set myself after looking for 3 years. I was advised to use cork gaskets with them. Yeah not surprised to here of your leaking woes, I don't know many people who rate those spacers.

[phazed]

My spacers never leaked.

Stuck them to the heads with a good rtv silicon gasket and used the rubbers dry on top.

[Matthew Poxon]

I thought you had those custom made jobbies on yours Peter? They do not need spacers do they?

[phazed]

Matthew Poxon said:

I thought you had those custom made jobbies on yours Peter? They do not need spacers do they?

I have now

[vaurien]

For the Merlin - cylinder heads it was necessary to lift the gap up to 10 mm.


The hydro lifters we convert to solid lifter and change the camshaft to Kent H224 to rich
higher RPM´s. Lighter flywheel and lighten crankshaft. We change the piston and lift the
compression. Also was a change on air in section.

On transmission we change the ratio of the 5th gear.





Regards


Gregor

Edited by vaurien on Tuesday 2nd August 20:13

[rev-erend]

Go for the standard yella terra's.

I have kenne belles on one set of RV8 heads and they were very good whether used with a hydraulic or mechanical cam.

I now run pep chevy roller rockers in wildcat heads.

[vaurien]

rev-erend said:

Go for the standard yella terra's.

I have kenne belles on one set of RV8 heads and they were very good whether used with a hydraulic or mechanical cam.

I now run pep chevy roller rockers in wildcat heads.

We used the standard yella terra´s but the Merlin cylinder head / valve cover dont let enough space.

[Matthew Poxon]

I am surprised the merlin heads did not have enough clearance for roller rockers. Being a performance head I would have assumed there would be plenty of room for roller rocker options.

[vaurien]

Matthew Poxon said:

I am surprised the merlin heads did not have enough clearance for roller rockers. Being a performance head I would have assumed there would be plenty of room for roller rocker options.

We too Matthew ! The target of our client was to lift the performance over 5500rpm. To begin we got standard steel rocker with chevy hydro-lifters but
the steel rockers shows material mistakes





for this type of rockers (without adjustment bolt) the space was ok with the Merlin heads ....





later we saw after the problem with the space of the valve cover that with installation of the chimaera exhaut manifold
we had no space for the standard spark and spark plugs





later





spark plug









Regards


Gregor

[rev-erend]

Here are some pictures of my Wildcat heads before the rods were installed..


With lifter rods


and my old RV8 stage 3 heads with kenne bells