351W block, Roller cam
- Thread starter js66coupe
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69gmachine
Member
Although they're more expensive, the link bar style lifters allow the use of off the shelf cams. You should be able to use '94 up roller pushrods depending on the heads you're using.
If you use the late model style spider and dog-bones, you will need a custom reduced base circle cam, and longer than stock (roller) pushrods. Again depending on the heads you use, you can probably get by with .100 longer small block Chevy pushrods.
Regardless of the way you go, you need to check the pushrods to make sure they are the correct length.
After trying two different reduced base circle cams (similar if not the same lift and duration but one with a 110 LC and one with a 112) I decided to switch to the link bar style so I can swap cams with off the shelf grinds. PM me if you're interested in either of my reduced base cams.
If you use the late model style spider and dog-bones, you will need a custom reduced base circle cam, and longer than stock (roller) pushrods. Again depending on the heads you use, you can probably get by with .100 longer small block Chevy pushrods.
Regardless of the way you go, you need to check the pushrods to make sure they are the correct length.
After trying two different reduced base circle cams (similar if not the same lift and duration but one with a 110 LC and one with a 112) I decided to switch to the link bar style so I can swap cams with off the shelf grinds. PM me if you're interested in either of my reduced base cams.
PoppyMod
Member
Hi,
My entry into a roller conversion was through the use of the spyder conversion in my 64.5 5 bolt block. It works well until you feel the need to take your performance improvements to the next level.
I'm currently running the link bars with a billet cam. As mentioned, the link bars are more expensive, but, when used in conjunction with full base circle billet cams, you have the basis for a more stable high performance valve train, when combined with the correct springs assemblies. If you have any flex or any deflections, you run the risk of compromising your cam events and loss in the cams expected performance.
I deem the spyder conversion as an inexpensive entry level conversion process on the road to a full high performance roller conversion. I still have my original components, but, now resides on the shelf.
With any change in valve train components and heads, I would advise checking the PR geometry.
Happy Motoring!
Consider solid lifters
If you're looking for maximum power and you're not concerned with vacuum or smooth idle, consider running a solid roller. Since solid roller lifters are shorter, they have better engagement in the shorter lifter bores of older blocks which helps high speed stability. They're also a lot cheaper last I checked.
If you're looking for maximum power and you're not concerned with vacuum or smooth idle, consider running a solid roller. Since solid roller lifters are shorter, they have better engagement in the shorter lifter bores of older blocks which helps high speed stability. They're also a lot cheaper last I checked.
jerry S
New Member
You have two options.
you can use a small base circle roller cam. This entails installing a spider in your block with drilling and bolting. This is the cheapest way to go. I think all you need is the spider and the cam.
the other way to go, which is what I did, gives you more options. It has its pros and its cons. The pros are that it does not use a spider so there is no machine work involved and you do not have to use a small base circle cam. the cons are that you need rather spendy link bar lifters (+$500), roller rockers, and most likely custom-made push rods. If your cam has an agressive ramp, you might also need some beefed up rocker studs and a stud girdle. My costs break down as follows:
custom grind cam: $250
valve springs: $120
Comp cams pro magnum roller rockers: $250
Comp Cams pro magnum roller lifters: $500
Comp Cams stud girdle: $175
Comp Cams composite distributer gear drive: $100
ARP 7/16" studs and nuts: $75
custom length push rods: $100 or so if I recall correctly
you can use a small base circle roller cam. This entails installing a spider in your block with drilling and bolting. This is the cheapest way to go. I think all you need is the spider and the cam.
the other way to go, which is what I did, gives you more options. It has its pros and its cons. The pros are that it does not use a spider so there is no machine work involved and you do not have to use a small base circle cam. the cons are that you need rather spendy link bar lifters (+$500), roller rockers, and most likely custom-made push rods. If your cam has an agressive ramp, you might also need some beefed up rocker studs and a stud girdle. My costs break down as follows:
custom grind cam: $250
valve springs: $120
Comp cams pro magnum roller rockers: $250
Comp Cams pro magnum roller lifters: $500
Comp Cams stud girdle: $175
Comp Cams composite distributer gear drive: $100
ARP 7/16" studs and nuts: $75
custom length push rods: $100 or so if I recall correctly
PoppyMod
Member
Hi,
As a follow up to what I and others have commented.
Yes, it is more expensive to go the link bar route, but, it is the right way to go. I have done both conversions and have the experience of performing both them. Yes, you will need to measure for correct push rod length to insure the geometry is correct (this is a "must do" and many of us have done it and and can advise) The PRs are no more expensive than buying a good set of "hardened" PRs. There a number of vendors with competitive pricing, so, Google and go!
As DIY'fer, the cost will be in the neighborhood of $600-700.
This should cover the lifters, PR checking kit, PRs, and intake gasket set.
However, what are you running for rockers? Add another $175 to $250 for rollers.
This is why a good custom built motor is $6000-7000.
Happy Motoring!
BTW, this is my 46 year old 289/333.
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