flatchat(Chris)
Supporter
Any body have experience with a rev kit in SBF -- such as :-www.pricemotorsport.com/Rev_Kits/rev_kits.html
Rev kit ?
- Thread starter flatchat
- Start date
They only appear to have one for the 351w 9.500" deck block, you might have to engineer your own for an 8.200" & it will depend on the cyl head your using & the way it is cast on the valley side of pushrod holes. Dont forget that 302w lifter bores are not parallel to cyls so you will need to take that angle into account when you machine or spot face the head [ probably with a suitable taper wound spring with small dia @ lifter end- ] . Worth doing though & IMHO would cure 90% of the premature roller lifter failures as it keeps roller in contact with lobe, plus it allows a reduction in actual valve spring pressures.
I have a rev kit in my SBC - the Hydra-rev kit from AFR. I probably never really needed it since the red line on the engine was only 5500rpm, but it might have saved my ass a few times during an over-rev situation. I don't see any reason not to have one, though, they can be a little annoying to install.
flatchat(Chris)
Supporter
All good info so far --- I have an LS6 engine and a Windsor 302 . The Ls (Chev)"performance tune" book mentions bent push rods and causes, thus the "rev kit" which souded like a good idea to help with lifter float without increasing valve / seat spring pressure.
A recent car club track weekend saw a LS engine failure in one pot -- bent pushrods and shattered piston.
( I do realise that, if you go racing -- then build a race motor!)
PS Dodge -- Dick Johnsons cars seem to be going hard these days --anything to do with you ?:thumbsup:
A recent car club track weekend saw a LS engine failure in one pot -- bent pushrods and shattered piston.
( I do realise that, if you go racing -- then build a race motor!)
PS Dodge -- Dick Johnsons cars seem to be going hard these days --anything to do with you ?:thumbsup:
Not necessarily planning to 'rev' my 418, but I do want a stable valve train. I've been eyeing the Jesel rocker shaft solution for quite sometime. Will wait till I get back in the states next year in case a better technology or materials come available. I believe it's being used in NASCAR and NHRA with excellent results. A GT-40 sitting on the side of the road, broken down is unacceptable to me.
Jesel Valvetrain - Pro Series Shaft Rockers
Jesel Valvetrain - Pro Series Shaft Rockers
flatchat(Chris)
Supporter
Noticed in the Jesel parts --the radial needle roller thrust race for the cam shaft --can't get my mind around straight rollers doing a radial movement --balls maybe --all I can see is needles eventually dropping into the sump to be picked up by the oil pump --just an observation :worried:
The rollers are placed radially:idea:..Lots of radial thrust needle roller units in modern auto & manual transmissions. Yes being a bit older I dont like the idea of those small bits migrating south to the oil pump pick up, but these guys are trying to sell stuff & make HP, I was looking at the John Kaase 385 series build the other night, lots of roller bearings and smaller crank bearing diameters allowed a reduced oil pump size, tighter brg clearances etc to make the HP...not sure about a 100000 mile warranty though...
They are also for people that are trying to make an antiquated configuration work properly (SBC).
In one case currently in our shop.
Rules call for Dart Iron Eagle heads.
The heads have 2.05 intake and 1.6 exhaust
The cam required (.600+ solid roller) needs 350+ pound springs.
The RPM range of the engine will be just south of 8,000
The valves centerlines Are each offset (by Dart).170" further apart than stock (so I was told).
This necessitates offset shaft mount rocker arms as there's not enough room in the head to angle the pushrods to use normal roller rockers.
Combine all this and you find that you also cannot use 3/8" pushrods because you'd have to cut into the intake ports to do it.
You won't get a 5/16" pushrod to live long with those valve springs at 8 grand.
So what has to change?
Only thing I can figure is the valve springs and in order to accomodate the RPM range with a lighter valve spring is a Rev kit...
That is unless you have some special smoke you can loan me...
flatchat(Chris)
Supporter
---to jump the que - any one had experience with electronic valve (EVC) actuating or camless valve timing --no sprockets, no chain, no lifters, no push rods, and no rockers -- mind you, the computer and solenoids may weigh more
PS Jac, I think that was a brake thing not the engine -- unless I missed something ?
PS Jac, I think that was a brake thing not the engine -- unless I missed something ?
Its 'your' thread Chris,... Yes I Realise it was a 'brake' thing, just another bit of missplaced Kiwi humour..
I always felt that replacing the valve springs with pressurised air cups had some merit...constant pressure--no valve spring harmonics..... Any attempt by me to write a programme for computer controlled valve timing would require very deep valve pockets in the piston crowns....like total valve lift plus 0.100"..........
I always felt that replacing the valve springs with pressurised air cups had some merit...constant pressure--no valve spring harmonics..... Any attempt by me to write a programme for computer controlled valve timing would require very deep valve pockets in the piston crowns....like total valve lift plus 0.100"..........
Terry Oxandale
Skinny Man
2X. Properly chosen quality components will be all you need, which doesn't include 5/16" pushrods.
