If you are going back with a stock head, the absolute maximum is .500" lift. However, I have heard of cams with .470" lift pull studs from a stock head. I have a Lunati with .488" on my 72. I really didn't want to go that high, but it's been cool so far. If you are dealing with an aftermarket head, there are way too many variables and you need to do your homework on the exact set of heads you have on hand.
If he swaps the heads over to E7's or GT40 irons, they'll handle more lift. I've run a B303 with 1.7 rockers with em (.510 lift)
i thought that as well.... i almost wen with the doug herbert 450 "horse" 347 they have for i think 4785 or something...since i have around 6300 in mine. but i have more quality components and mine uses the 5.315 rods instead of the 5.4 Yanno, I have heard that...
pullin the chute I'm going to keep the 302,... for now. If I have anymore questions, ill post them on a new thead. Thanks! Keep the rubber side down.
I've heard the same thing more than a few times myself. Although, it is rumored that they used the same or similar mixture of Iron/Nickel/Tin that Ford has used for years. I've built some high HP motors using the very same blocks, and not had any issues. I understand that the actual casting they used was the old "GT" casting from years before. The trick to making any of them have the right longevity is to use screw in plugs where the press-ins were. On the other hand, I've also seen quite a few of the "new casting" 5.0 blocks laid to waste doing high HP applications. I think for my money, I'll just stick with what has worked for me for many years.
That's to be expected since Ford gradually lightened the weight (iron content) of the block over the years to gain fuel economy. By the time the roller blocks came around, the metal was paper thin in relation to early blocks. They had to shave weight everywhere they could to meet EPA rules.
Not true Dave. I don't have the weights for the early (pre 77 blocks) but the D8VE block weighs in at 136 lbs.This block has thick walls and webbing like the Mex block. The blocks to avoid are the 1980-84's, these are the light weights at 120 lbs. Ditto for the first rollers (122 lbs) the 1986-2001(E6SE & E7TE) roller blocks had another 4 lbs added to the decks and bore bottoms (126 lbs) It would be a safe bet to assume the F1SE blocks have the same iron content if not more than the other two previous blocks. I'd like to see the weights for the 68-71 blocks and see how they compare. The biggest weight trimming was done with the switch to the 50 oz cranks. The early 50's are junk but the late 80's-up cranks have such excellant casting quality that they look almost like forgings.
The blocks were lighter later, the iron was redistributed from critical areas to places like tall lifter bores for roller lifters, as an example. The blocks split down the middle for cryin' out loud. You can look at them cross-section in the pics and see how thin they are. They did lighten them by a few pounds, and they would be substantially lighter if they didn't have to add material here and there for modern internal upgrades like roller cam. I may not have the details dead on, but they are thinner and lighter, they are prone to split, and the reason they strived to lighten things up everywhere in a car was to meet EPA regs.
The only time they were lightened was in the early 80's blocks. After that Ford added iron to em. Sure the lifter valley floors may be(I'd still like to measure that myself to see how much) thinner than the early blocks, but the rest of the cross sections aren't. Ford Racing's catalog lists the last roller block's weight at 135 lbs, that's another 9 lbs added over the second & third roller block castings.
Then, by all means, explain the "late cast" 5.0 blocks that split from the mains to the top of the cam journals under heavy, hard use (N-A, Nitrous or blower). I myself had one in a 92 5.0 that didn't need any bolts removed to take what was left of the motor out of the engine bay. It blew up so bad, that the input shaft of the W.C. T5 sheard off completely. It was later replaced with a Mex block/ Art Carr "super" C-4 and had a steel crank, good H beam rods and Forged pistons that, as far as I know, is still together (5+years later). The guy I did that motor for has since gone through that block a few times over and hasn't had another incident.
Well, I guess you haven't been reading the threads so far. The whole discussion came about via the Mex block 302.
I never said the stock blocks tended to not split. It's only when you get to a certain level of stroke, rpms and rotating mass that does this. If you're going to do this, it needs to be done in an aftermarket block anyway. What I did say was Ford did not decrease the iron content of the roller blocks. They added iron, not subtracted it. I looked at the two roller blocks I have in storage and the lifter valley floors are about 1/8 to 1/4" thick. I think the place the split starts is the ragged hole poked in the forward wall of the valley. Some have a ragged hole in the rear wall too. Do something about relieving the stresses here and the chances of the block splitting would go down I think.
As far as destressing/deburring, that is good with any motor/block. I've done it to every race engine I've ever assembled. Including installing restrictors in the valley to prevent oil from draining directly on to the crank/cam to prevent any excessive loss due to over oiling. Basically you force the oil to return to either the front or rear valley drains. The main weak point that I've found in the newer blocks is the webbing, or lack there of, between the crank bosses and the cam journals. Now, this fail point can be slowed (not prevented) in later model block designs, with the use of a girdle, deburring and installing screw in frost plugs. 8K + RPM is going to spell death in any motor that is fatigued or not built correctly, but even a well built late model 302 with or without stroker setup will NOT live as long as a well built early 302 or Mex block 302. Obviously, any modification outside the normal "stock engine" setup will have negative effects on the longevity of any engine, but going on "bang for the buck" I would seek a relativly-available, garden-variety 302 out of something pre 1977. You can usually find old LTD's and Granadas still rotting out there with decent engines in there just dying for a rebirth of sorts.
