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65cobraking 06-01-2006 07:44 PM

Dove's 427 aluminum block
 
How good are the Dove's aluminum 427 blocks?

Michael4yah 06-01-2006 07:59 PM

Ive got Dove Hi Rise Alum heads, Dove Tunnel wedge intake, Dove roller rockers.......But I'm putting it all on a Pond Aluminum Block.

Sizzler 06-01-2006 09:16 PM

sorry, but so what?

none of it is 'real' Ford now is it?

Put your aftermarket heads next to your aftermarket intake and bolt everything to your aftermarket block.

I don't wear Levi shirts with my Levi jeans. Same non-issue.

Hope everything works out for you and more importantly, works well together.

Michael4yah 06-02-2006 12:14 AM

65 Cobraking.... Dont mind Sizzler, he must have had a bad day at Wrigley. Of course nearly every day at Wrigley is a bad one. Dove makes a lot of nice stuff. Some Alum blocks are better than others. Unless your running 1200 hp the Shelbys are overpriced but whats new. For the money I like the Dove roller rockers and I think their Alum heads are better built than most. Robert Pond is a national record holder and has raced FEs for 30 years. To set a national record these days with an FE engine is deserving of a medal in itself. I'm sure the Mopar and Chevy guys have a hard time dealing with it. Dont worry about having a stock iron FE. I owned my 1st 427FE in 1968. They're as heavy as steamship anchors. Using an Alum block, heads and manifold will lighten up that front end by 250 lbs. The one thing that Ive learned in this process is to "Please yourself and to hell with the Everyone Else". Most of them dont own original Cobras anyway. And if they do they probably inherited them...Michael

RedCSX1 06-02-2006 02:50 PM

Dove is nice but I also have a Pond
 
Another Pond Aluminum. Really pleased with the quality of the block. Exterior looks like the stock side oiler. Has certainly made my life easier.

lineslinger 06-02-2006 03:03 PM

AAAHHHHH............Cub Fan, that explains it.

fostereast 06-04-2006 10:19 AM

Heavy as Steamship Anchors???? OR NOT
 
The stock 427 block weighed aroung 200LB or less. The Aluminum blocks weigh as much as 130 or so. For a 427 Iron block, the sideoiler is not heavy, check out Chevy's, and others. As far as I know there was no Iron manifold make for a street/race 427, so the most you will save by going all aluminum is around 100-130LB.

The new iron blocks are heavier, but the originals were not that heavy.

Michael4yah 06-06-2006 12:46 AM

Foster, I think what I meant was an overall weight savings of 250 lbs, You forgot to mention the Alum heads, alum fly wheel, cast crank. I think the originals had Magnesium intakes but had Forged cranks (1965-67). I mispoke, All the 428s had Cast iron intakes. I had an original 64 427 in 68. I should have remembered that. Whats 40 years to someone with an iron trap for a brain!! Where did we leave off???? Oh yes,

This coming from a CC member:
""I weighed my stroked 427 on a stock car electronic scale and it was 503#. This is a cast iron block 427 with 428 crank (452 ci), dove alum heads, canton steel oil pan, Edelbrock water pump, lemans rods, complete FPP rocker arm setup, alum Weber intake, and alum Weber like throttle bodies.""

Now take the 503 minus the 82 for the alum block = 421. Near what I said it would be. 625 - 421 = 204 lbs. So you can see 250 lb reduction is within sight.
The overall savings on the Forged Crank using a rotating weight ratio is worth about 100lbs in itself, 17lb difference X 6= 102 lbs. The way thats calculated is that it costs 6X more to turn that Forged crank than it does to carry the extra weight of it. I know, it sounds like the new math all over again.

But the proof will be in the pudding. I have a near perfect example of a true Shelby Cobra in my Alum Hi Tech, The only difference is that the main tubes are built a hair thicker and the frame supporting the body is slightly larger, and we use the stronger Ford 9' IRS instead of the salisbury. The weights of most original Cobras are coming in at 2530-2550. Im shooting for 2300. One of the most important aspects of this lighter engine other than it will corner better will be to reverse the 51/49 weight bias to near 50/50. If you reduce the frontal weight 100 lbs it then becomes exactly 50/50. Im counting on the remaining weight savings to overcome the slightly larger frame and the Ford 9".
Michael

DavidNJ 06-06-2006 11:45 AM

Quote:

Originally Posted by Michael4yah
The overall savings on the Forged Crank using a rotating weight ratio is worth about 100lbs in itself, 17lb difference X 6= 102 lbs. The way thats calculated is that it costs 6X more to turn that Forged crank than it does to carry the weight of it. I know, it sounds like the new math all over again.

I'm not sure I understand that. Alloy steel and cast iron have similar densities, and cranks add next to nothing to rotational inertia.

What did you mean?

lovehamr 06-06-2006 01:10 PM

OK, I'm a math rock, but I'm lost as well. Is this supposed to be a cost analysis?

Michael4yah 06-06-2006 05:15 PM

A one pound reduction in the weight of a crank assembly is worth 6 lbs of total weight reduction in a car. Basicly its like this, Youve got two cobras. One with a cast crank and another with a heavier forged crank. The difference is 17 lbs. So in order to make things equal you add 17 lbs of weight to the cast crank car. Now the cars should perform equaly right? Wrong. Overcoming 17 lbs of carried weight is not the same as overcoming 17 lbs of power robbing weight resistance @ the crank. Try this, If you had the same two cars equal in weight and gave each a gallon of gas and told to drive side by side @ 60 miles per hour do you think they would both run out of gas simultaniously? Nope, the car with the forged crank would have to expend more energy because it had to overcome the added resistance weight of the crank. Thats why one of the most important keys to building racing motors is to build a rotating assembly that "just covers" its structural needs. No extra weight. Not just because its carried weight but because its the kind of weight that robs power. In fact in racing if all other things are equal the one that has the smallest margin of strength/weight in this area will win. (As long as it stays glued together and flex or other issues dont play a substantial part.) A gram here a gram there it all adds up. It gets more complicated but this serves as a general basis for building motors. These examples dont work for tractor pulling and other feats of torque. And of course if your running Nitro you might want to keep that forged crank!! Ive never seen a well built properly installed cast crank die in an FE unless it was in a much higher hp engine than we're talking here. Anyway, thats my 2 cents. Michael

DavidNJ 06-06-2006 05:41 PM

I sorry, but you're wrong. The mass on the crank is at most at radius of 3-4". Most of it inside of 2". In fact most of it in the main journals, if they large and not gundrilled as on an FE. There is very little inertia in a crank. May 3-6 lb-ft^2 in the heaviest big block. That is maybe 3-5lbf-ft of torque under aggressive acceleration. Most of the rotational mass of the engine assembly is in the flywheel and clutch which is at much larger radius.

Second, iron and steel are approximately the same density. Less than a 10% difference at most. And that is usually made up by needing extra metal to make up from the lower yield strength. In a big block crank, a lot of the mass comes from the counterweights to balance heavy piston/rod assembly.

Now, you could order the crank with gundrilled rods and mains. You could use small rod journals...even small crank journals. Those large sizes were designed for a big safety factor in 1950s engines with low end cast materials. You could build an engine with 2.25" mains and 1.771" rods, gundrilled. You could use Ti rods and short compression height, small ring, small pin pistons that would need less mass on the crank to balance. That would save weight.

Note that the effect of the inertia is dependent on the rate of acceleration. The amount of HP that translates to is dependent on engine speed. So an F1 engine at 20k rpm or a ProStock or Nascar engine at 10k rpm have a bigger interest in low inertia. Also an engine with 800hp accelerating a 1500lb car (higher rate of acceleration) makes more difference than in a 300hp engine accelerating a 4000lb car. Also note, that braking occurs at much greater rate than acceleration, and blipping the throttle to match revs even greater. So the effect is noticable there.

Michael4yah 06-06-2006 06:33 PM

We agree to disagree.

Sizzler 06-06-2006 06:47 PM

Quote:

Originally Posted by DavidNJ
...
Second, iron and steel are approximately the same density. Less than a 10% difference at most. And that is usually made up by needing extra metal to make up from the lower yield strength. In a big block crank, a lot of the mass comes from the counterweights to balance heavy piston/rod assembly.
...

I think you're missing his point: it isn't that iron and steel are 'approximately' the same density and therefore one would think that the weight difference is minor. It's that an FE cast crank IS (IS as is actual measured FACT) 17 pounds lighter than the steel FE crank. And both can be gundrilled and/or have work done to lighten them, but the crank is the same size, and the same lightening work would just result in one crank being STILL, 17 pounds lighter. On an 80 pound crank, that's more than 10% weight savings.

And all honors to theories, but actual real world facts are that the lightest rotating assembly, including the crank, wins.

As for the Cubs and Wrigley field. In my dotage, large sweaty foul-mouthed drunken fans and slatternly women in hard uncomfortable seats have lost their one-time allure for me. Even the skyboxes at Wrigley, well, let's just plain out say it: they suck too.

The new Sox stadium is much better nowadays, as long as you're down in the lower tiers, or better yet a skybox. Fans seem a better class too. Food is better (orders of magnitude better in the skyboxes), fireworks are better, access is better.

None of this is to imply I'm either a Cubs or Sox fan. Even though last year, I saw a game or two of the Sox, I'm more of a night-out includes a game once in a while guy than any sort of 'fan'.

Has anyone ever actually USED a Dove block? That's what tips my boat. Or at least have some reason, based on a 'theory' or fact, other than, "I picked x block just because"?

One theory I might put out there regarding a Dove aluminum block is this: I think Dove uses the same molding for aluminum blocks as it does for their iron blocks. Aluminum blocks should have some modifications made to their castings due to the nature of the materials. So: has anyone actually built an engine using a Dove block, aluminum or iron, and if so, what was the reality?

Michael4yah 06-06-2006 07:34 PM

Sizzler
 
Sizzler. I talked to Earl of Dove (sounds like a title) yesterday on their blocks. I wanted to be fair and talk directly to them rather than listen to people who may or may not know anything about it. Like I said I have many Dove parts but so far Im still leaning towards a Pond block. Have you seen em? They are beefy and beautiful!! I have photos in my "MY Pictures" but I dont know how to post them here. If you will give me your email address I'll forward them to you.
On the Cast Vs Forged deal, Anyone who has taken the two cranks and spun them by hand can tell the difference. It doesnt take a rocket scientist or fuzzy math to make up my mind. People get sold on the idea of a forged cranks all the time when the engine builder knows they dont need it. I think they do it for two reasons, one they make more money for sure and two He knows no matter what it aint coming back no matter how badly the owner treats it. I have never seen a adequaltely installed quality cast crank die in an engine of 700 hp or less. It seems to me that there are other things that will go 1st. Especially if your using a stock Cast Crank and Ford rods. Naturaly the rods will go 1st. On the Chevy journal rods who knows. Ive never seen one go back.
Michael

DavidNJ 06-06-2006 09:24 PM

A Crower BBC crank weighs under 60#. If you take a cast and alloy crank of equal strength, the alloy will be lighter. Which 'forged' crank are you using for comparison? Don't the Scat cast cranks have gundrilled rods, 2.2" rods, and profiled counterweights?

The difference from density would give a 4# advantage to the cast. On a strength basis, the advantage should go to the alloy steel. For reference, Scat lists their BBC lightweight cast crank (equivalent to the FE) at 67# and their BBC cranks at 70#, 65#, and 59# for their standard, light, and superlight weight respectively.

What it feels like in your hand and what it feels like to the engine are not the same thing. The physics is very clear. and easily calculated. If an 80# crank was an infinitely thin hoop at the outer edge of the connecting rod throw, it would have less inertia than a 13# 11" flywheel.

To me its amazing, given the limited selection of FE parts, that there are at least three aluminum blocks (Pond, Genesis, Shelby) to choose from.

thudmaster 06-06-2006 11:05 PM

I'm totally lost but I like the part where you say I've got 2 cobras. :LOL:




Ed

bret a ewing 06-07-2006 05:49 AM

I don't believe you will achieve enough traction in a cobra with street tires to break a cast crank. Scat engineers agree. Something else will break first.

DavidNJ 06-07-2006 06:15 AM

Why would traction affect the crank? Do cranks break on launch? With drag slicks, it should be possible to get quite a bit of traction.

RedCSX1 06-07-2006 07:50 AM

Quote:

Originally Posted by bret a ewing
I don't believe you will achieve enough traction in a cobra with street tires to break a cast crank. Scat engineers agree. Something else will break first.

Bret,
Did scat engineers say that somewhere? I think the Scat accountants decided that. Forged cranks are very costly. It is much cheaper to have a crank cast over seas, therefore a greater profit margin can be made on the sale of a large quantity of cranks at a cheaper cost.

Just for the record, I am running a Scat crank in my Pond aluminum 482.:)


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