427 FE vs 351w, advantages?

[madmaxx]

Isnt there an engineer on this forumn that can calculate the difference in torque vs weight/rotational mass? If we know the mass of the crank, rods, pistons (cam is a wash) we could calculate exactly what the difference in torque is required between small block and big block.

[RodKnock]

Well, if someone asked my opinion, and I realize no one has, I would say "Who cares?"

The OP has already chosen an FE for his Kirkham.

More importantly, what oil filter do I use for my next oil change?

[Avmaviator]

Originally Posted by RodKnock

Well, if someone asked my opinion, and I realize no one has, I would say "Who cares?"

The OP has already chosen an FE for his Kirkham.

More importantly, what oil filter do I use for my next oil change?

Haha, I enjoy seeing how many posts we can make about a few grams here and there :-). At these horsepower figures I doubt you would feel it that much anyways. How many people on here use, and know how to use, 100 percent of their engine anyways? I don't think the majority at all. For street driving I don't think it matters nearly as much as being smooth and reliable, but heh, thats just me...

It will be FE all the way, now just have to put the right package together. I talked to Steve at Kirkham this afternoon and I'm all set up for a shop visit/purchase in 1.5 weeks, woohoo!

[madmaxx]

I have not posted but I actually did additional filter testing, this time at 100C oil at 5900 rpm through 3rd gear into 4th. Amazing I have not been arrested yet. I had some interesting findings but to cut to the point I found the Royal Purple at 5900 rpm resulted in 3-4psig more oil pressure!!!!! I was at 56 psig with the Ford racing and motorcraft FL-1A and decided to try the Royal Purple and was blown away. In addition as you may remember the Royal purple filter to 20 micron where the Ford is 25 micron. So in addition to better filtering it has less pressure drop when you need it the most. In the end alot of nothing is nothing though, but the RP did win out on both cold and hot oil.

Originally Posted by RodKnock

Well, if someone asked my opinion, and I realize no one has, I would say "Who cares?"

The OP has already chosen an FE for his Kirkham.

More importantly, what oil filter do I use for my next oil change?

[RodKnock]

Originally Posted by madmaxx

I have not posted but I actually did additional filter testing, this time at 100C oil at 5900 rpm through 3rd gear into 4th. Amazing I have not been arrested yet. I had some interesting findings but to cut to the point I found the Royal Purple at 5900 rpm resulted in 3-4psig more oil pressure!!!!! I was at 56 psig with the Ford racing and motorcraft FL-1A and decided to try the Royal Purple and was blown away. In addition as you may remember the Royal purple filter to 20 micron where the Ford is 25 micron. So in addition to better filtering it has less pressure drop when you need it the most. In the end alot of nothing is nothing though, but the RP did win out on both cold and hot oil.

Maybe you can work them over a little on the exterior color.

[xb-60]

Originally Posted by RodKnock

Maybe you can work them over a little on the exterior color.

What I want to know is how much do they weigh?
Cheers
Glen

[CobraEd]

Originally Posted by madmaxx

Isnt there an engineer on this forumn that can calculate the difference in torque vs weight/rotational mass? If we know the mass of the crank, rods, pistons (cam is a wash) we could calculate exactly what the difference in torque is required between small block and big block.

Crank, dampner and flywheel are rotational mass. Rods and pistons are reciprocating mass. Not sure which is more of a deterent to fast rpm and building good power, but both are bad.


.

[Excaliber]

I care!!!!! I'd much rather check out an FE, of any size by anybody, tricked out, or not, than a W small block, of any size, tricked out or not.

I put the W motors in the same camp as a Camry. I keep a picture of a Camry on my bed side table. When ever I have trouble sleeping, I look at that pic,,,, and I'm straight off to sleep land. Maybe I should try a W engine picture, I bet it has the same effect!!

[Jerry Clayton]

As for crank weights---today I balanced a couple of engines--altho both were chev they are representative of what we been talking about---the sbc with a 3.75 stroke(1/4) weighted 47 1/2 lbs--the bbc 4 .250 strke weighed 62 lbs---these are both fairly lite wt internally balanced cranks so the counter balance weight is on the crank, not flywheel or frt dampner

[madmaxx]

With a difference of 14.5lb (alot of ounces) it would be impossible for the dumptruck big block to rev as fast as the small block. One truck engine will be linear in acceleration where the small block will be exponential. It comes down to performance or looks. A 500hp small block will beat any 500hp or larger big block in a blast from zero to 60. The small block will spool up faster and more than 500hp in a cobra cannot be effectively put to the pavement.

Originally Posted by Jerry Clayton

As for crank weights---today I balanced a couple of engines--altho both were chev they are representative of what we been talking about---the sbc with a 3.75 stroke(1/4) weighted 47 1/2 lbs--the bbc 4 .250 strke weighed 62 lbs---these are both fairly lite wt internally balanced cranks so the counter balance weight is on the crank, not flywheel or frt dampner

[RodKnock]

Originally Posted by madmaxx

The small block will spool up faster and more than 500hp in a cobra cannot be effectively put to the pavement.

There's a guy named Blitz that may want to argue that point.

Assuming you think 10.75 seconds for a 1/4 mile is effective.

[blykins]

Originally Posted by madmaxx

With a difference of 14.5lb (alot of ounces) it would be impossible for the dumptruck big block to rev as fast as the small block. One truck engine will be linear in acceleration where the small block will be exponential. It comes down to performance or looks. A 500hp small block will beat any 500hp or larger big block in a blast from zero to 60. The small block will spool up faster and more than 500hp in a cobra cannot be effectively put to the pavement.

Just to be fair, I have to say a few things here....

If you've never heard a 470-480ci BBC spinning at 8000, then it's something you have to hear once. I see a lot of pulling motors on the dyno that would probably out-rev any small block on this forum. It's not impossible...

Also, you have to watch what generalities you use about 500hp small blocks beating 500hp big blocks because that's not entirely true. How quickly you rev doesn't win races. I'd rather have a 500hp 408 than a 500hp 347. I'd also rather have a 500hp 482 than a 500hp 408. I've been in them all....there's no comparison.

Rod makes a very valid point.....Blitz's "slow revving" big block on less than desired tires put it all over that quick revving Ferrari.....and didn't have trouble with traction at 700 hp.

[rodneym]

Maybe some of you experts can answer:

Assuming you have a SB and BB with the same redline, I can see how the SB would spool faster in nuetral, but what about under load? Wouldn't the mass of the BB then help?

[bobcowan]

Originally Posted by Jerry Clayton

As for crank weights---today I balanced a couple of engines--

That means the BB crank is 32% heavier than a SB crank. The rest of the rotating and reciprocating assembly is probably a lot closer in weight. But still, you can expect the entire assembly to around 30% heavier. That's a lot. A tire and wheel assembly that's 5# lighter is a real boon to the racer. So why wouldn't a similar weight savings inside the engine provide a similar benifit?

I'm not arguing with anyone, I'm asking the question. I sure would like to see real data on that sort of thing. Not only HP and torque on an rpm scale, but also on a time scale. I think that would be interesting.

Originally Posted by madmaxx

With a difference of 14.5lb (alot of ounces) it would be impossible for the dumptruck big block to rev as fast as the small block. One truck engine will be linear in acceleration where the small block will be exponential. It comes down to performance or looks. A 500hp small block will beat any 500hp or larger big block in a blast from zero to 60. The small block will spool up faster and more than 500hp in a cobra cannot be effectively put to the pavement.

I wouldn't think it would be imposible, but I think it would be difficult. I think (but could be wrong) that if you built similar Windser and FE engines (compression, head specs, cam, etc) and raced them, the SB would win. The rotating assembly is lighter, and most likely quicker. The BB is heavier all around, and weight is the enemy of any race car.

And, yes, you can put more than 500hp to the ground effectivly. It's been done many times. It's just not easy.

Besides, who really cares about HP anyway? It's torque and area under the curve that matters. The slightly longer stroke of the FE may give that engine an advantage.

[blykins]

I may owe madmaxx an apology if he was referring to a small block and a big block of the same displacement. I took it that he was comparing a much smaller engine to a much larger engine.

As for rotating weights, momentums, inertias, etc., I think you guys are putting too much thought and concern into it.

Your typical 427SBF is based on a 4.125" x 4.000" combination. Your 428FE is based on a 4.130" x 3.980" combo. Essentially the same specs. Yes, the FE rotating assembly might weigh a little more, but when it comes down to it guys, both are going to make a buttload of power/torque and it will come down to traction and driver ability to see which car would cross the finish line first.

[RodKnock]

Originally Posted by blykins

Yes, the FE rotating assembly might weigh a little more, but when it comes down to it guys, both are going to make a buttload of power/torque and it will come down to traction and driver ability to see which car would cross the finish line first.

I'm scurrying around the Internet trying to find the definition of "buttload."

That's "buttload" with two t's right?

[Jerry Clayton]

I have a destroked bb crank around somewhere, when I run across it I'll weigh it--

I have seen 500 in bb that went over 10000rpm. In 1980s my 4 in stroke engines repeatedly came back with the tattle tale tack at 10.3

This sbc crank I weighed is only a 3.75 stroke--and all your 427 small blocks will be 4 or 4.125 stroke whereas I can do a 427 bb at around 3.78 to down around 3.25 stroke and the bigger bore will let me use some much bigger valves ---

I think we got a crank in today for a 427 sbf so I'll weigh it later or maybe tomorrow.

[Jerry Clayton]

Scat 4340 forged 4 inch stroke counterweights cut for 6.2 rod length Cleveland main size===55 lbs

[fordracing65]

Any bb that people claim over 8000rpm redline would cost more than the car and or would only last 500 miles, think nascar motor, revs high, don't last.

[madmaxx]

Blykins I always value your opinion. I always go to the extreme when trying to understand something. I would think a 500 hp 351 stroked to 427 would outperform a big block (427,460,482) putting out 500hp due to less rotational mass assuming same driver, same car.

References to big or small blocks turning 7,8,9,10K rpms is not applicable to 99% of cobra owners or the old farts on this forumn. I would guess most do not go north of 5K rpm by the silly analogies I hear about kidney killing acceleration. True these cars are fast compared to a honday, lexus but nothing as compared to a "race car".

As far as longevity of a properly stroked small block I would think 100K miles is reasonable if the right components are used. Roller rockers, heavy duty pushrods, balanced rotating assembly etc.