Roller rockers on non-roller cam??

[Turbo047]

Hey guys,

I was wondering if I'm going to have any issues running the roller rockers off a M7 head on an M3 head with non-roller Cam?

Back story is I'm rebuilding my 2.6 Turbo with flat tops, 1mm over size and a ported M3 head I've had lying around for a while. I'm taking off the M7 head I was running with Hydraulic lifters and the flat cam followers with a non-roller cam. (It had a bit of ticking in the valve gear while it was running.) I've compared the two rockers side by side and they look the same dimensions. I did want to use the manual adjustment rockers from the Astron 1 but the valves are shorter on the M3 and the angle is all wrong and not much thread left for the lock nut. (probably the reason I didn't use them the last time the engine was overhauled 7 years ago.)

Anyone tried this before?

[amgis_obrut]

wont work the cam profile will be all wrong for a roller

[cheaterparts]

Hey guys,
I did want to use the manual adjustment rockers from the Astron 1 but the valves are shorter on the M3 and the angle is all wrong and not much thread left for the lock nut. (probably the reason I didn't use them the last time the engine was overhauled 7 years ago.)

there are a couple of options -- will the lock nuts fit under the rocker

or change to set of elephants feet adjusters ( a VW part ) Superscan probably has a dozen sets laying around and would have the part no for sure

[Superscan811]

Cheers.

[geezer101]

Seeming you guys have touched on the subject of the VW styled tappets, it will be good to get info on using these. First up it looks like they're oil pressurised - do they need to an oil feed to work and if that's the case, how do you do it? I've also seen a few people try using these without success due to clearance issues (lack of adjustment) Do the rocker arms require some other modification to allow installation? I am considering using these swivel feet tappets (once I get over the hurdle of finding a set of replacement non-hydraulic rocker arms and an inlet rocker rail on a G63B I'm wasting my time on rebuilding...)

[cheaterparts]

Seeming you guys have touched on the subject of the VW styled tappets, it will be good to get info on using these. First up it looks like they're oil pressurised - do they need to an oil feed to work and if that's the case, how do you do it? I've also seen a few people try using these without success due to clearance issues (lack of adjustment) Do the rocker arms require some other modification to allow installation? I am considering using these swivel feet tappets (once I get over the hurdle of finding a set of replacement non-hydraulic rocker arms and an inlet rocker rail on a G63B I'm wasting my time on rebuilding...)

on the 4g54 I found they fitted straight up no mods - yes in the Vee Dub they are presure feed however in an OHC there is that much oil spashing around in the rocker cover they sean to stay well oiled with out presure feeding them

I use to wear the ends off the std type adjuster bolts quite quickly in my race engine , they ended up all rounded off
the swivel feet have worked a treat
and my engine spent a lot of its life up around the 7000 rpm and with a sizable cam

as for the 4g63 it suck it and see if they fit -- sorry cant help you

[SteveG]

There is a guide online on how to drill the rockers to allow for an oil feed to the tappets but for the life of me I cannot find it again but as Cheater said, not really needed. I have used in the same situation as him.

[Turbo047]

But what I'm asking is has anyone tried using the rollers before? And if so did it work?

I've looked at the "Street Machine" 308 Holden V8 web sites and you can get roller hydraulic lifters that drop straight onto a standard flat tappet cam and I'm thinking if they can, why can't we on our engines?

I've got the head on with the rollers and have turned it over on the engine stand by hand and everything seems to work fine.

I'm a little worried that the ported head I'm using has double valve springs and the spring pressure may over come the hydraulic lifters.

I'm willing to forgive a little horsepower for a smooth quite engine. Not after MAX POWER at the cost of a smooth, quite, powersteered and air conditioned ride. (I've deleted the balance shafts in the past and HATED IT. Heavy vibration between 2500 and 4000 rpm, just where most of my power is. NASTY.)

I'm sure someone has actually tried it before. and if it didn't work I'm interested to find out why.

(and thanks Cheater the lock nut would fit under the rocker. Didn't think of that )

I

[Superscan811]

But what I'm asking is has anyone tried using the rollers before? And if so did it work?

They will "BUT it changes the rate of lift.
The flat tappets will lift the valve quicker because their effective diameter (of the slipper surface) is much greater than the roller followers.

I'm a little worried that the ported head I'm using has double valve springs and the spring pressure may over come the hydraulic lifters.

With double valve springs, you would also need wider rollers, to spread the load. The standard rollers would work for a while but will likely fail a lot sooner.
As for the hydraulic lifters, I honestly don't know if they would leak down or not.


Cheers.

[cheaterparts]

But what I'm asking is has anyone tried using the rollers before? And if so did it work?

I'm sure someone has actually tried it before. and if it didn't work I'm interested to find out why.

I

http://www.starquestclub.com/forum/inde ... pic=137964

there was a post way back on Starquest about putting 1.6 ratio rollers on a magna roller car -- in fact I think it may have had a thread here to
but the problem was the valves didn't close to the seats

I didn't look any further at this but I'm sure with some playing with valve lenths or having the cam reground a little smaller this would have worked
by fitting the ratio rockers also opened the lobe centers from 110 to 114 deg that would have been a great mod for a turbo motor

But at the time I just got my Cam guy to grind up a 31/79 cam with 114 deg lobe center and that ended up in Karls baby sh!t brown galant
and it worked very well -- for a low boost street car

[geezer101]

I would think using hydraulics with double valve springs would be somewhere between a waste of time and a bad move. The extra load would prevent the lifters from working at full capacity. I'm not 100% convinced double valve springs are a good idea in the first place as I have seen badly chewed rocker assemblies (and even a cam lobe wiped off...) on heads that have had them installed.

[cheaterparts]

I have seen badly chewed rocker assemblies (and even a cam lobe wiped off...) on heads that have had them installed.

sounds more like the cam not run in properly or the oil used didn't contain zink than the double valves springs

[Turbo047]

Ok looks like no one has tried it yet. I'll give it a go and see what happens. Can't see a major problem and it's easy to change out a set of rockers. I do like the Elephant foot idea and will go down that road if the rollers are problematic.

I'll let you know how it goes. (although the engine is mostly together I work really slowly. (mainly due to having a few beers while I work and having to check or redo it the next day )

Thanks for the comments and ideas. Always good to hear constructive opinions.

[Scorpma82]

It sounds like a 4G52 cam will fit and suit a street friendly N/A 4G54 Astron II quite nicely andreep respectable rewards.... Would I be right with that????

[amgis_obrut]

has anyone got a roller and a non roller to compare lobe shape

I have a feeling they will be noticeably different

[mic_77]

Both profiles are very different best way is to use a roller cam with roller rocker gear but remove the hydraulic adjusters fit inserts and run Porsche (mahle) lash adjusters just my opinion.

Cheers Mic

[cheaterparts]

Both profiles are very different best way is to use a roller cam with roller rocker gear but remove the hydraulic adjusters fit inserts and run Porsche (mahle) lash adjusters just my opinion.

Cheers Mic

the only thing the Hyd cam wont have quitening ramps like a mechanical cam so there will be more shock loads in the system

[Dion383stroker]

I was hoping to go the same path. My machinist currently has my head. M6 mild port, double valve springs, roller rockers and hydraulic lifters. He sent a new cam away to Crow to be reground to suit turbo with roller rockers. Will see how it looks when I take delivery later this week.

[Dion383stroker]

Both profiles are very different best way is to use a roller cam with roller rocker gear but remove the hydraulic adjusters fit inserts and run Porsche (mahle) lash adjusters just my opinion.

Cheers Mic

Do you have more details on fitting inserts? I like the Porsche lashes and are cheap.

[mic_77]

Porsche lash adjusters are not cheap the copy's from scat and other brands are and it really shows in the quality of the product you need to look for mahle-wizemann as they supply them to Porsche any more info about the inserts you will need to talk to Paul Testa he is the one doing it.

Cheers Mic

[mic_77]

Try Pelican parts in the us they are the cheapest to get the real thing

Valve Adjusting Screw
- 911, 911L, 911T, 911E and 911S (1965-73)

Brand:
[More Info]

Rating:

(12 per car, sold individually)

Part Number: 901-105-370-02-M62
$27.25

Cheers Mic

[Turbo047]

Hey guys,

An update on how I went.

Well it does run but I was hoping for a quiet engine and that's not what I got. Sure it runs but there's a fair bit of noise coming from the valve gear. It looks to me like the normal cam lobes are a smaller overall diameter and there is about 8mm of free play in the rockers. Probably too much for the hydraulic lash adjusters to take up.

Anyway worth a try. Now looking for the SCAT adjusters Cheater and Superscan recommend.

Superscan would you have a set you would like to sell me???

[leigh7005]

will a series 1 cam work in a series 2 head with the adjustable rocker gear?

[stealth]

Sure will !
its only the roller cam that has differant
base circle ,will never work with factory
mix n match components ,lol
cheers stealth

[leigh7005]

will never work with factory
mix n match components???? what do you mean by this.

ive got a series 1 turbo cam but was hoping it will fit the series 2 head if i put the adjustable tappets on aswell simply because the larger valves

[stealth]

Your right leagh
i meant a rollor cam with flat tappet rockers
you can use a flat tappet cam and rockers in astron two
this post is a exersize in not understanding how cams work!
cheers stealth

[Turbo047]

Not having a roller cam or ever seeing one before is the reason for the question at the start.

Nice of you Stealth to jump on the end after all is said and done to provide us with some 20 20 hind sight!