roller conversion question
#1
roller conversion question
Hey guys, I have a 71 302. I was thinking about converting it to a roller cam. I know they make a roller conversion kit through comp cams and ford racing but I have seen people on ebay selling roller version parts off of used roller motors like the spider and lifter hold downs and evn the old roller lifters. Could I just use a used spider assembly and be ok instead of 50-60 bucks for new?
#2
Forget going roller. It's going to cost you a minimum of $600 to complete the swap, without starting with a roller block first. There are two ways to do it. One is to use the roller block hardware, but you'll need a custom cam with a reduced base circle to use this. That cam will run you $300-400. Then add another $100 for custom pushrods. Then a new cam gear for the distributor ($50) Add that to the cost of the roller hardware and lifters. The other route uses Crane's linkbar lifters and the stock & aftemarket 5.0 roller cams. You'll still need the steel cam gear on the distributor and the lifters run about $450, plus the cost of the cam (as little as $50 for a good used roller)
#4
With the Crane lifters, you don't use the factory retainer hardware. The lifters are linked in pairs using link bars. They just drop in the holes and you're done. Best thing about going this route, is you have more cam choices for less money. And you don't have to drill and tap the lifter valley floor for the retainer bolts. I just went thru this sort-of. Went to chase the threads in the holes in an 89 5.0 from an F150 to use a roller and the tap went too deep and screwed the cam bearings below. Luckily I had a new set of bearings on hand to replace those two.
#6
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#8
You can use any of the 5.0 cams with a std base circle.(this includes all the Ford Racing "alphabet cams") As for the pushrods, check with Crane for that. And if you still have the stock 1971 heads with their pressed in rocker studs, those will need to be converted to screw in type studs. A roller cam's more agressive profile and the stiffer valve springs you'll also need, will work on the pressed in studs and pull them loose from the heads. A cheap alternative would be a head swap to 87-97 E7TE heads or any of the GT40 series heads with pedestal rockers. Then the rocker hold down bolts will limit your cam choices to less than .550 lifts. As you can see, a roller cam swap entails more costs than you might first think. This is also true for the more agressive flat tappet cams too, but the cams and lifters don't cost as much to start with (generally speaking)
#9
You haven't listed what your 71 motor has now, but if it's still stock, a simple cam swap to something like an RV type cam will wake it up considerably without having to spend for all the extra stuff such as springs, retainers, studs,etc. What you're looking fo rin this is a cam such as Summit Racing's part number SUM-3601 which specs at 204/214 duration @ .050 with a .448/.472 lift. Or Comp Cam's 268H. This one is 218/218 @ .050 lift is .456/.456 Any cam with less than .510 lift and 220* duration @ .050 should work with your present valvetrain.
#10
It is stock but had been rebuilt once bored 30 over but needs another build now. Wanting to go all out and get quality heads like the 165 AFR's. Maybe a rpm intake or stealth and a streetable performance cam like the E-303 cam. Want something drivable so I'm thinking about a edelbrock 600cfm with electric choke
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#14
Yea, it's a good one. Holley's do get old though and the first thing wears is the throttle shaft bushings. And the tiny passages in the metering block get gummed or plugged with trash. The only other parts that give trouble, mainly just when they sit for long periods are the powervalve and accellerator pump diaphram. These get dry and brittle and rupture. But they're easy to replace, you can buy either at many parts houses individually. Keep em clean and supplied with clean, moisture free fuel and they'll last a long long time.
#15
to roller or not-to-roller...
...I guess it all boils down to how fast ya wanna go?
I just aquired a '56 F100 with a '72 302 & C4 and cannot decide if
I'm gonna keep it or go with an FE motor...
Anyway...I also have an "extra" carb'd 302, complete, on a stand in the garage from a mid-to-late '80's Mustang that was running when pulled...
Now...I've always been an FE freak but...ya know......with all these
small-blocks layin' around it's hard to justify the cost of goin' a
different route!!!
Sooooooo. because the '56 only weighs in at about 3240 lb.s AND small-blocks RULE....I think I gonna go this route...Check it out:
http://www.fordmuscle.com/archives/2002/04/331/
I just aquired a '56 F100 with a '72 302 & C4 and cannot decide if
I'm gonna keep it or go with an FE motor...
Anyway...I also have an "extra" carb'd 302, complete, on a stand in the garage from a mid-to-late '80's Mustang that was running when pulled...
Now...I've always been an FE freak but...ya know......with all these
small-blocks layin' around it's hard to justify the cost of goin' a
different route!!!
Sooooooo. because the '56 only weighs in at about 3240 lb.s AND small-blocks RULE....I think I gonna go this route...Check it out:
http://www.fordmuscle.com/archives/2002/04/331/