I do not believe that the 302's have a longer lifter bore. I have never seen it. The only difference is the roller blocks have two holes that are drilled and tapped in the valley pan This allows the spider plate to screw down and hold down the lifters. I didn't mention it for this poster because he said he was on a budget, which is extra $$$ for the conversion kit! Ford started tapping the blocks sometime in 87 I believe, someone else may have a better guess!

 

I'm with Conanski... A torquey 302? 351w would be a lot better choice

 

Personally I would go with the roller from a longevity standpoint. If you are able to find a wrecked 5.0 explorer in your local boneyard they have the ideal donor components they have the roller components and the crank that has the 5.0 HO/351 firing order. They also have the GT40 heads. There are carbureted intakes for these heads then all you would need to get really good power is the ford motorsport E303 cam or perhaps the B303 cam. I am going to be building one of these shortly.

 

One reason for sticking with the 302 is that the engine im building was given to me with low miles.. and the pickup already has a 302 in it.. and when i run it (either in the mud runs or just playing) it blows people minds that it has just a plain jane 302 in it.. the 302 has served me well both in this pickup and in the old cougar i had.. i may have misrepresented what i am after out of this engine.. im needing my power from the area of 1500 up to around 5500 rpm.. that is where that engine spends most of its time running is at least 3000.. but i do drive it on the street as well.. so that is why i was looking into the cam that is rated from 1300-5600.. and from what i have read (being on a budget) than this one seems to be my best bet until i can get the funds stored up to build a better engine from a later block.. that is if im not pleased with what this one is doing.. but my other engine is getting a little tired.. been abused to much and to long... so that is the only reason im really looking into replacing it... and if this one doesn't do what i am after (just a little more power than i already have) and turn those 35" tires a little better.. than i am looking at the next block to be a 351...

thanks for the info everyone...

 

Quote:

Originally Posted by Conanski

So in my opinion it's not worth it to convert an older motor, just select a flat tappet cam and forget about it.

This is exactly what I did when I rebuilt my 400; the cost of parts & labor (several
hundred dollars) aren't justified in my mind on a truck that has approx 1k miles
per year put on it (mine is mostly a utility vehicle that I use for hauling firewood
in the winter, all this fix-up stuff is just cuz it's fun).

 

i agree... im not doing high speed drag racing.. just mud bogs.. so i dont really need the really high power... just some acceleration and keep those tires digging... this pickup may get 3000 a year on it.. and that is if we are having a good wet year... i have a few friends (with mud trucks as well) that are running 400+ horse engines.. and i dont see where they are accomplishing much other than throwing a bunch of money at something that will never pay for itself... now i make a little money with mine.. go to the sand dunes.. pull people out.. and people pay for it no matter how much you argue (came home $30 richer last weekend from one pull).. but i dont go very often.. as well as people just being stupid int eh mud... they "donate" as well.. so i cant justify a 1200+ dollar engine.. just the basics with a few extras to help.. my good pick.. it makes money.. so more gets spent on it.. but needing a $1500 4.6 to put back in it... this will be engine #3...

 

Thanks for this info. It is great to be able to learn even when I'm an old man. Is this true with the older 460 blocks like in 1986?? I believe the newer 460s not sure what year used roller cams. Because that would make a difference if I ever rebuild mine. The cost of cam & lifters OK but add several hundred for machine work maybe a flat tappet cam will be OK.
Thanks, Craig

 

sorry guys my first post. the 302 "valley tapping" started in 85. mustangs, crown vics, and grand marq. they used a 302 roller up to 95 in the mustangs. the 96-01 explorer's also have the roller 302 as well as gt40 and gt40p heads.

 

Since you brought this old post up, I will have to disagree with the previous post that says "the roller blocks do not have longer lifter bores". They do in fact have longer lifter bores to support the lifter, since it sits higher in the block. Why? Because it now has a wheel on the bottom of the lifter and you need room for that and the base circle of the roller cam is larger also. And of course all this requires it's own special length pushrod. Also the top of the lifter bores in the engine I had looked like they were cleaned up a little bit to give a flat area for the dog bone piece to lay in.

 

Roller cam will give you more low RPM torque than equivalent duration flat tappet. Rollers can handle steeper ramping, which means they can hold the valves at max lift value for longer than a flat tappet, but because this doesn't physically increase the duration of the cam you just get an enhanced power curve across the same range a similar spec flat tappet will run. It doesn't move the power up the power curve just because its a roller.

very vague generalisation but I think you get the idea, whether the gains are worth the conversion cost & hassle to you is the question. I'm having a similar debate with myself on a cleveland build atm.

 

a cleveland, you lucky *******...

 

The "spider" sits in the valley above the camshaft, and it has arms that reach over to each lifter.

The roller blocks I believe started in '85. And I think thats when they switched to "5.0" from "302", as well as a one piece rear main seal, and I think at the same time they went from a 28 oz imbalance to a 50 oz.

The '95 was the last year for the 302/5.0 in Mustangs (until 2011) but it continued into this century in Explorers.

 

Yes, the roller blocks started in 1985. Even though the F150 came with a roller block, they still used flat tappet cams well into the 1990s. The Ford Mustang, however, got the roller block and a roller cam for the 1985 model year. 1985 was the last year for a carbureted Mustang, and 1985 was the ONLY year that the Mustang offered both the 4V carb AND roller cam.

As for when Ford started calling the 302 a 5.0, that came much earlier. I do know that in 1982, the Ford Mustang GT still used a flat tappet cam and 2V carb, and the car came with the famous "5.0" emblems on the side. I think the "5.0" and "EFI" moniker was placed on the F150 intake starting with the 1987 redesign, however.

For some reason though, I noticed that most people tend to call the Mustang motor the "5.0", and the truck motor the "302," regardless of the year, even though they are basically the same.

 

lol, clevelands are dim a dozen here. Ford Oz put them in everything including the family shopping trolleys of the day, even our 302's are clevelands aside a couple of exceptions. Until the mid 90's a windsor was a rare commodity here. When Ford US stopped supplying clevelands due to them as I understand it not been used in any US vehicles anymore ford Oz cast their own 2V headed version till 1986. They came factory fitted with 4bbl carter thermoquad carb & bosh electronic ignition. That's the factory spec motor for Oz F100's 1980 to 1986 .

 

On the roller cam cam issue comp cams has a free down load called cam quest or something I think lets you play with a couple a variables & swap flat tappets for roller spec cams & give an estimated dyno graph ......... how their dyno stats compare to real world engine outputs I don't know but the comparisons from one combination to the other is interesting.