5.0 Ho.... Weaknesses?

[LJS30]

I think we all agree that the 5.0 HO is a legendary engine, not quite the 350 Chevy, but nonetheless a staple of Ford performance. However like any engine, what are the primary weaknesses of this engine? I've asked all kinds of mechanics and Ford enthusiasts, and to this day they have nothing bad to say about this engine. What is your take?

[84mark]

well, it's really a computer-controlled power system rather than simply an engine...i don't think the durability of the moving parts is in any question, and the electronic control systems became well-developed...maybe you could say that it will simply be future-outmoded by more sophistcated power systems....

[NYC LS8]

The block. It likes to split in two at around 500hp.

[LJS30]

The block. It likes to split in two at around 500hp.

Yes, a definite weakness indeed. :lol

[NYC LS8]

Other than that, I don't see any.

My little 302 runs with 350 Tuned Port 3rd gens on drag radials...which gives me enough to talk some smack ;)

[LJS30]

Other than that, I don't see any.

My little 302 runs with 350 Tuned Port 3rd gens on drag radials...which gives me enough to talk some smack ;)


:)............. :)

[Kit Sullivan]

For the kinds of power outputs Ford envisioned, the 302 was stout indeed.
I am really impressed that they went to the trouble to change the firing order on the HO blocks so that there would not be two plugs firing consecutively at the front of the motor, which tends to put a lot more stress on the crank snout.
The revised firing order helped the parts live longer.

[macx]

For it's intended usage and targeted power output
(key points in this type of discussion) the 302 HO is
probly one of Ford's better efforts.

However, I have long maintained that Ford routinely set lower
performance targets than the other makers.

Not that they didn't have fully capable hardware, they
just usually didn't utilize it. And when they DID go for
the gusto, they went off the deep end to the point the
motors either weren't very street friendly (Boss 302 - a
hell of a race motor but sorely lacking in torque for
a daily driver - a friend of mine had one)
or were either made of unobtanium or weren't even
available in a production car (SOHC & tunnel port 427s) or they emasculated a fantastic motor (Boss 429 with it's single small carb, lo-po intake and small cam). Seldom
did they put together a widely available and mass
produced package that effectively competed with widely
available top offerings of other makes (short lived and rare Boss 351C, and esp the outstanding 429 SCJ). Although the 428 CJ was a stout torque motor, they used "pedestrian" heads and intake when some improvements in those 2 key
pieces could have made for a package much more
competitive with i.e. the 375hp 396, 400 Ram Air,
etc.

They did somewhat the same with the 302 HO. Although
a great small dimension light weight package with a
very durable short block and a really decent stock cam (talking hot street, NOT 500hp weekend only race toys)
they choked the POTENTIAL to easily hop it up with small heads and a strictly torque biased intake. That means faily major expense to realize the potential for a component matched package that really has strong street potential for us "masses."

As a comparison, look at the heads & intake on the 340 Mopars and hotter sbc's. They didn't need replacement
to arrive at a really healthy yet flexible street motor.
The 351W's suffered from similar problems. On the other
hand, the Clevelands in 4bbl form had OVERSIZED heads
for good flexible street performance, and most were
detonation prone open comb chambers.

Seems Ford has usually had problems making a well
matched combo. When a popular Ford magazine can
take a stock 302HO shortblock incl stock cam and simply
add good heads, intake, & headers and gain
100+ hp and still have a very streetable motor, I think
that clearly illustrates the point.

[gadget73]

Never thought the bottom ends were all that hot. Lots of sloppy ones at around 120k. They run for years and years with a rod knock and sloppy bearings but its annoying to hear them crank over. This seems to be a general Ford Windsor "feature", with the 302 and 351w being somewhat prone to it. Not sure if its poor oiling or soft bearing materials that cause this. I'd suspect bearings as often they will be down to copper substrate, and the crankshaft is still perfectly within spec. The block itself holds up amazingly well. I've seen several high mileage engines with visible factory crosshatch marks in the cylinder walls still. The heads were not so hot, especially pre-e7 heads but they didn't really have the annoying valve seal failure issues that Chevy smallblocks are prone to. It also seems the head bolts aren't exactly the best. Several folks on here have had them snap for no apparent reason, and a friend of mine also had one break for absolutely no reason. The rest of the motor as far as durability is concerned is pretty well designed. With regular maintainence they will go for quite a long time without fear of massive failure from an inherently poor design. My only real big beef with the engine design is the water pump and accessory bracket system. I really do not understand why they felt it neccesary to attach every single thing on the engine to the water pump. It just seems to make changing the pump a much bigger job than it should be. Luckily it isn't a regular service item so not that major, but still annoying.

[eVole420]

My friend had a 302 Boss and it seemed to have plenty of torque. He was given a mustang with the 302 boss in it for free from a neighbor, man I almost shit bricks when they gave it away in perfect running condition. :)

Just from my expierence the 302 boss seemed to be lacking torque towards the midrange but the bottom end was plenty.

[Kit Sullivan]

I owned 2 70' BOSS 302s, and they were both as described: somewhat lacking in low-end torque.
Of course, they were only lacking when you compared to thier own power once the engine 'got up' on the cam.
The 70 BOSS 302s were slightly modified from the factory over the 69s to alleviate this very situation.
Make no mistake, though...they were no 'slouch' at low RPM.

[eVole420]

The boss my friend had I believe was later in the late 80's, I'm not a bigg buff on american muscle history so If I'm wrong just tell me :) But i believe it was in an 89 stang the "fox" body as some call it.

[gadget73]

If it was an 89 it should have been the same 5.0 HO thats in the Mark VII. The Boss 302 from the late 60s/early70s was essentially a factory "clevor", or 302 Windsor shortblock with the 351 Cleveland heads. I think it was only made for 69-70 so its not a long lived engine at all. Sometimes the cars had a custom paint scheme and were called Boss 302 but it has nothing to do with the engine.

[Kit Sullivan]

To an owner of a 'real' BOSS 302 circa 69/70, this is one of our biggest 'pet-peeves'.
Just because someone has a 302 in a Ford product does NOT make it a BOSS 302.
Even if it is hopped-up, and might even produce more power than a real BOSS 302...it is NOT a BOSS 302.
The 'real deal' was rated at 290 horses, probably closer to 325-350.

300-350 is not too terribly difficult to get out of any 302 today, what with all the speed goodies out there.
Even so, that don't make it a BOSS 302.

The 'specialness' of an authentic BOSS 302 Mustang is not just the power the motor creates. It is the whole package that was the car called a 'BOSS 302'.

To some degree, I have seen the same thing with guys that have plain-jane 5.0s in thier Cougars, T-Birds, Crown Vics, etc...and they just slap the 'HO' plenum cover on it and claim its a "5 liter HO".
The ones of us that have real, authentic BOSS 302s, 429 Cobra Jets, 455 Super Dutys, BOSS 351s and even the 5.0 liter HOs don't like to hear about people with plain-jane motors and claiming they are what they aren't.

[2manymarks]

Those kind of claims are fraud and nobody thinks well of those that claim MORE than is really there. However, the beloved sleeper , where there is MORE than is claimed, is looked on as cool.