Big Block vs Small Block maintenance

[ldmclain]

Here goes...

Deciding on engine for my Unique 427 SC build... gonna be a weekend street rod... may go to track once or twice if ever.

Leaning toward BB (427 side oiler) but keep hearing that BB's leak oil and spark plug change takes 4hours, and even simple maintenance is a hassle

Anybody got any input on maintenance requirements or difficulties with BB vs SB?
Thanks in advance!

[redmt]

Any engine leaks with improper assembly. Changing plugs in an FE has to be one of the easiest engines around. The plugs are above and inboard of the headers/exhaust. There's pluses and minuses to both styles of engines. I can't actually think of any pluses for the Windsor style block but I'm sure there must be something. Of course 50 years experience with FE motors does give me a biased opinion.

[rodneym]

4-hour plug changes? That's a new one to me.
If you're just maintaining then I don't really see a difference.

[cycleguy55]

If an FE is properly assembled there is no reason why it s/b more likely to leak than a similarly-prepped Windsor. Don't forget the products used today have improved significantly since both engines were introduced and manufactured, and those newer products (e.g. RTV sealant) help a lot. Yank an FE out of an old clunker and run it "as is" and it is probably far more likely to be a leaker than one assembled today.

[DanEC]

The 4 hour plug change story for an FE probably dates back to when the 390 first appeared in the Mustang in 1967. I remember all sorts of horror stories on trying to reach a couple of the plugs due to the spring towers and other stuff. Seems like the passenger side was the tightest. I had a friend with a 69 390 Mach 1 and he ran around for weeks with a loose plug in the thing because he claimed he couldn't figure out how to get in there to tighten it.

Except for the driver side back plug being a little tight - they are pretty easy to get to on my ERA. A flat tappet hydraulic or roller hydraulic cam FE that's properly assembled should be a good reliable and low maintenance motor.

[dcdoug]

Originally Posted by DanEC

The 4 hour plug change story for an FE probably dates back to when the 390 first appeared in the Mustang in 1967. I remember all sorts of horror stories on trying to reach a couple of the plugs due to the spring towers and other stuff. Seems like the passenger side was the tightest. I had a friend with a 69 390 Mach 1 and he ran around for weeks with a loose plug in the thing because he claimed he couldn't figure out how to get in there to tighten it.

Except for the driver side back plug being a little tight - they are pretty easy to get to on my ERA. A flat tappet hydraulic or roller hydraulic cam FE that's properly assembled should be a good reliable and low maintenance motor.

I had a '67 Mustang GT S-Code (390) in high school. Changing the plugs was a PITA since for some of the plugs near the shock towers you could only turn the ratchet 1 click at a time due to clearance. Not sure it took 4 hours though.

But I have a ton more space with the 427 S/O in my cobra, especially for plugs. Header bolts can be a bit more of a hassle though, but not sure how this compares to windsor motors.

[Large Arbor]

I have a 427 BB and its not hard to change plugs. Certain things are more difficult to do than others, but I would not have it any other way. Most oil leaks can be resolved with the right stuff or TA-31.

Phil

[Grubby]

Zero difference for normal maintenance.

John

[Dimis]

Originally Posted by DanEC

The 4 hour plug change story for an FE probably dates back to when....

30mins to change the plugs. 3 1/2hr to marvel at the beauty of the FE, while sucking down a couple of you favourite beers.

Same same as a small block... but unless the small block has webers, after 30mins you're closing the hood to hide the shame.


3, 2, 1...
Take cover!!!

[patrickt]

I know that Ernie (Excalibur) told me he had to cut a little trap door in the foot box to get to Plug #8 on his early ERA, but with the modified foot boxes on the later cars, changing the plugs on my #732 is as easy as it gets.

[lovehamr]

Friends don't let friends put tiny little motors in big engine compartments.... ;-)

[RodKnock]

If you don't drive it, then a BBF is very low maintenance.

[keezling]

Try a California '67 Mustang with thermactor tubes. Undo motor mounts, jack one side of engine up at a time.

[olddog]

Keith Craft once explained that the FE engines were designed for rope seal on the back of the crankshaft. As such, there was no need for precision machining back in the day, but today's seals require the gland to be more centered than what the factor did. Hence the FE reputation for marking its territory. So yes a factory block FE is more likely to drip some oil out the rear main seal. And let's skip talking about the nails in the seal between the rear main cap and the block.

If I recall correctly Keith said he had tried and gave much thought to the problem and even he could not achieve 100% leak free FE engines. I have heard others state if anyone tells you they can, stay away from them cause they are either an idiot or a lyre.

Now if you us a modern new block, I would expect the rear seal issue have improve dramatically, but I have no personal experience.

The FE is a very complicated design compared to a SB. When assemble by a knowledgeable experienced FE builder, it is a great engine. When assembled by other builders with little FE experience, your asking for trouble. That can be said to be true for any engine, but the less complicated the design the better chances are any builder can do it.

So the answer, in my opinion, depends on who is building what.

[wkooiman]

I had a 428 in a 67 Mustang. It didn't leak, and it wasn't difficult to change plugs. You just have to use the proper extensions and universal joints.

It did not have thermactor, and it didn't have the shock tower reinforcements either. It was originally a 289 car.

I currently have a 428 in a Contemporary Classics Cobra. Spark plug changes are simple, but this one does leak a bit. It is an older build, completed in the early 90's. I am piecing together a 427/482. When it is finished, it will not leak.

Your kit might be harder to change plugs.

FEs cost quite a bit more, and it's harder to get parts too, but in my opinion it's worth it.

The #1 question I get with my car is, "Is it real?", followed by, "Does it have a side oiler?" When I open the hood, they go, "Wow!". You don't get that with a 351W.

Power wise, it depends on how they're built. You can built a 351W in the 427" range pretty easily, and it will make more than enough power.

But it will never look like a 427 FE with 2x4s and S&H air cleaners.

[redmt]

Originally Posted by olddog

If I recall correctly Keith said he had tried and gave much thought to the problem and even he could not achieve 100% leak free FE engines. I have heard others state if anyone tells you they can, stay away from them cause they are either an idiot or a lyre.

Idiot or a liar? Really? I guess only a fool would believe that. Either that or it's just somebody looking for an argument.

[patrickt]

Originally Posted by redmt

Idiot or a liar? Really? I guess only a fool would believe that. Either that or it's just somebody looking for an argument.

No, you just redefine "No Leaks" to mean something different. Ford actually did that in the 1960's when it instructed its dealerships to treat small drips from the FE as "commercially acceptable." Personally, I define "bone dry" as three dime-sized drops or less, dropped within a 24 hour period, after a hard run.

[66gtk]

In my experience, all FEs "leak". Bone dry, should mean bone dry. That is, if you lay a piece of new plastic under your car after parking it - you should be able to confidently remove the plastic in a few days or weeks and prepare your next meal on it. "dry" is "dry" and a "leak" is a "leak" whether it be a drip or a stream.

I've purchased several FE Cobras in the past couple years and ALL of them were advertised to me as "dry" and "leak free". Guess what - every one of them leaked. (So did the SBF) I don't even bother to ask anymore. I simply ask, "where are your leaks coming from?" The response is a lot more telling than "Does it leak?"

[redmt]

Originally Posted by patrickt

No, you just redefine "No Leaks" to mean something different. Ford actually did that in the 1960's when it instructed its dealerships to treat small drips from the FE as "commercially acceptable." Personally, I define "bone dry" as three dime-sized drops or less, dropped within a 24 hour period, after a hard run.

Yep you could look at it that way. I have a couple 8-71 Detroits and in them I define no leaks as anything that doesn't actually drip. They emit oil seemingly through solid castings at times. In this case on FE engines I have had a couple leak. Lets call a leak anything that is visible and not necessarily a drip. Back to OD's original statement of %100 leak free. If you qualify the %100 to be of all FE engine ever built, he would be correct. If you say that any FE cannot be made leak free then that is a false statement. Any FE engine that is properly machined and assembled does not leak.

[patrickt]

Originally Posted by 66gtk

In my experience, all FEs "leak". Bone dry, should mean bone dry.

You may believe that "bone dry" means bone dry, but I believe in the land of alternative facts.