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Author
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Topic: Roller cam in a 351W?
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68DARKHORSE
Gearhead Posts: 445
From: Austin, Tx
Registered: Aug 2002
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posted 01-12-2004 09:55 AM
   
I've heard that you can clearance an early block (around lifter bore) for the 5.0 dog bones and use stock 5.0 lifters.Can I use a 5.0 with that setup? What is the reason for small base circle roller cams? Do 5.0 roller blocks have larger cam journals than early blocks, or will an E cam (for example only) slide right in my '74 351W block? Thanks
Alton
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Dubz
Gearhead Posts: 1890
From: Manitoba Canada
Registered: Oct 2002
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posted 01-12-2004 02:49 PM
I would also be interested in how that would work. Would be a heck of a lot cheaper than buying aftermarket i would think
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Mpcoluv
Gearhead Posts: 1333
From: Charlotte NC usa
Registered: Apr 2001
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posted 01-12-2004 03:09 PM
It is a very simple retrofit.
You just drill and tap two holes in the valley for the "spider" hold down screws and run a special reduced base circle cam.
Comp makes teh reduced base circle cams.
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68 S-code GT
Gearhead Posts: 2962
From: Sayreville, NJ, US
Registered: Mar 2000
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posted 01-12-2004 07:58 PM
Or if you don't have a block yet get one of the last 351Ws made. 94-97 block start of with F4TE. It's already taped and I think some of the old body style 1997 F250s might have a roller cam in them.[This message has been edited by 68 S-code GT (edited 01-12-2004).]
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CHIPSBAD67
Gearhead Posts: 396
From: LOU,KY;USA
Registered: Sep 2003
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posted 01-12-2004 08:13 PM
whats this "base circle" talk? dark, you are all over the place man. the journal and the base circle are two different things. the base circle is rarely gonna be an issue and 351w cams and 302 cams are interchangeable, just keep the firing order correct with the cam. i dont know about clearancing for the "bones, but the lifter valley will have to be drilled for the retainer. considering the 351w is a wider block im almost certian the retainer will have to be purchased or modified to work in the 351. also you will definetly need longer pushrods. you will have to be sure to get the correct length pushrod after motor is assembled.....------------------
306, 4speed, 4.11's....best 1/8 mile 7.58 at 92mph with 1.72 60ft. PUMP GAS/NO ADDERS/STREET TIRES
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Mpcoluv
Gearhead Posts: 1333
From: Charlotte NC usa
Registered: Apr 2001
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posted 01-13-2004 07:30 AM
quote:
Originally posted by CHIPSBAD67:
whats this "base circle" talk? dark, you are all over the place man. the journal and the base circle are two different things. the base circle is rarely gonna be an issue and 351w cams and 302 cams are interchangeable,
The Base circle is a big deal because the Hdy roller blocks have the oil galleries for the lifters in a slightly different location.
So the lifters designed for these blocks have the oil groove in a higher spot than flat tappets. So you use a reduced base circle cam to orient the OEM roller lifter to the older blocks oil gallery.
The cams will all go right in regardless of base circle.
Note that Comp makes lists "Retrofit" cams (reduced base circle)for 302/351 and 351C. BTW the mega dollar ($420) Crane "Drop in" hyd roller lifters have the oil groove located so that normal base circles can be used.
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68DARKHORSE
Gearhead Posts: 445
From: Austin, Tx
Registered: Aug 2002
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posted 01-13-2004 10:38 AM
Thanks everyone. quote:
Originally posted by Mpcoluv:
The Base circle is a big deal because the Hdy roller blocks have the oil galleries for the lifters in a slightly different location.
So the lifters designed for these blocks have the oil groove in a higher spot than flat tappets. So you use a reduced base circle cam to orient the OEM roller lifter to the older blocks oil gallery.
The cams will all go right in regardless of base circle.
This is the kind of answer I was looking for. I also found in the back of my FRPP catalog, that the roller blocks have taller lifter bores due to the taller height of the roller lifters.
It's like Ford just stuck the rollers on the bottom of the flat hydros, which raised everything up. So, to get the roller lifter in the correct position, you have to use the reduced base circle cam.
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Mpcoluv
Gearhead Posts: 1333
From: Charlotte NC usa
Registered: Apr 2001
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posted 01-13-2004 04:37 PM
quote:
Originally posted by 68DARKHORSE:
Thanks everyone.
This is the kind of answer I was looking for. I also found in the back of my FRPP catalog, that the roller blocks have taller lifter bores due to the taller height of the roller lifters. It's like Ford just stuck the rollers on the bottom of the flat hydros, which raised everything up. So, to get the roller lifter in the correct position, you have to use the reduced base circle cam.
Yep.
FWIW the 351C Comp retrofit roller cams made for use with the OEM roller lifters have a 1.025 to 1.050" base circle compared to "stock" 1.30 base circle.
BTW FRPP sells the "Crane" roller lifters for slightly less than the Crane versions.
$395 or so versus $420.
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CHIPSBAD67
Gearhead Posts: 396
From: LOU,KY;USA
Registered: Sep 2003
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posted 01-13-2004 11:07 PM
the base circle (which is refering to the lobes) and the journals are two different things. you wouldnt mix hyd. roller cams and flat tappet cams parts for any reason, therefore the base circle conversation is mute. this stuff about the lifter bores in roller motors being longer is a new one on me, which having built motors with both, i highly doubt is true. look at an oem roller lifter, it doesnt make contact the full length of its shaft like a flat hyd. yes they are longer and yes the cams have smaller base cicles (for other reasons including the fact that its a longer lifter). other than tapping the block for the retainer and using the correct roller parts, there should be no reason to sweat this other stuff. im not sure how it would work in a 351w lifter valley, i cant remember if the valley if too wide for the 5.0 retainer to reach the "bones" or spiders or whatever they are called. i know the 351 takes a longer pushrod than the 302. mpcoluv, youre right, but thats not the only reason for the smaller base circle on a roller. its not gonna take a bunch of specialty crap to make this work. like i said, dont mix roller stuff with non roller, keep the cam with the lifters it was designed to work with and the base circle isnt an issue, ever. lifter bores aint deeper on a roller block and dont need no retrofit stuff. ------------------
306, 4speed, 4.11's....best 1/8 mile 7.58 at 92mph with 1.72 60ft. PUMP GAS/NO ADDERS/STREET TIRES
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jeffstar
Gearhead Posts: 123
From: Toronto, Ontario, Canada
Registered: Feb 2003
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posted 01-14-2004 03:58 AM
I use the F4 block with factory 5.0 roller lifters, I like it. You might want to check out the latest Ford motorsport catalog,I think they where advertising a set of roller lifters that work with conventional block.
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Mpcoluv
Gearhead Posts: 1333
From: Charlotte NC usa
Registered: Apr 2001
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posted 01-14-2004 07:23 AM
Chip,
I am not saying that converting a non roller to a roller requirese any "special parts". What I am saying is that you need to run a readily available retrofit Hyd Roller cam (from comp) that DOES have a reduced base circle compared to the hyd roller cams designed for the newer "roller blocks".
If you run an X303 or whatever cam in an older block, you will have top end oil problems and the lifters will probably rattle.
Don't take my word for it, call Comps toll free number and ask them.
BTW the spider/Dogbones setup will work in any 289/302/351W/351C. I have heard that you may need a .125" hard washer "spacer" under the spider for proper clearence.
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N266fords
Gearhead Posts: 1652
From: Sierra Vista ,Az USA
Registered: Apr 2003
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posted 01-15-2004 04:19 PM
The reason they have reduced base circles is because the lifter bores are shorter on the old blocks and the liftes will pop out of the spyder retainer with a reg cicle roller cam, But you can use the retro roller cam sm cirle or the lifters with the top link bars and a reg roller cam.thats the difference.Bruce
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kid vishus
Gearhead Posts: 6405
From: middle of NC
Registered: Oct 2000
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posted 01-15-2004 06:16 PM
quote:
Originally posted by CHIPSBAD67:
...this stuff about the lifter bores in roller motors being longer is a new one on me, which having built motors with both, i highly doubt is true.
Sadly, you are mistaken, it is true. The lifter bores are taller in the factory roller motor blocks than in the early motors. That is why the early blocks require the small base circle cams like was explained earlier.
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