440 vs hemi ? - how do the blocks differ?

Posted By: nutso suave

440 vs hemi ? - how do the blocks differ? - 09/07/10 05:23 AM

i was looking at the stage V website and i saw you can buy hemi conversion heads for your 440 or 383. how do the blocks differ? i ought to know, but i confess that i don't. the bore is listed as 0.10" smaller with the same stroke.

4.25" 3.75" - 426
4.32" 3.75" - 440

are there any other differences other than the bore? and stampings, obviously.

Posted By: 540challenger

Re: 440 vs hemi ? - how do the blocks differ? - 09/07/10 05:28 AM

Quote:

i was looking at the stage V website and i saw you can buy hemi conversion heads for your 440 or 383. how do the blocks differ? i ought to know, but i confess that i don't. the bore is listed as 0.10" smaller with the same stroke.

4.25" 3.75" - 426
4.32" 3.75" - 440

are there any other differences other than the bore? and stampings, obviously.

The head bolt pattern is the big one and Hemi's had cross-bolted mains.

Posted By: 340SHORTY

Re: 440 vs hemi ? - how do the blocks differ? - 09/07/10 05:29 AM

IIRC

a HEMI has 5 bolts around the cylinder and cross bolt mains.

a 440 only has 4 bolts around the cylinder..

Posted By: WILD BILL

Re: 440 vs hemi ? - how do the blocks differ? - 09/07/10 05:31 AM

I know the headbolt pattern is different.

Posted By: IMGTX

Re: 440 vs hemi ? - how do the blocks differ? - 09/07/10 05:39 AM

Hemi heads will bolt onto a 440 block except for the bolts along the lifter valley. The Hemi intake ports sit right over those holes so they moved the holes into the valley an extra 1/2 or so to allow the bolts to be accessed from underneath. In effect the 4 bolts in the lifter valley go up into the bottom of the head while all the others go down through the head into the block.

Also the lifter valley had a deeper groove cut into it to allow the pushrods to miss the block since they were at a different angle.

Lastly the corners of the Hemi heads had drain tubes to let the oil drain back into the oil pan. The 440blocks have no provision at all for the drain tubes.

The other differences are the 4 bolt mains and the original hemi has no mounting ears for motor mounts. They use flush mounted motor mounts. Some current production blocks have both.

Posted By: nutso suave

Re: 440 vs hemi ? - how do the blocks differ? - 09/07/10 06:01 AM

thanks!

Posted By: badmoon

Re: 440 vs hemi ? - how do the blocks differ? - 09/07/10 07:40 AM

That is a total crock.
440's and for that matter ALL B/RB engines have 5 head bolts per cylinder just as hemis do.

What is different is: a slight difference in location of the 5th bolt at the top of the pentagon. Plus a HUGE difference in the way it is accessed.

Posted By: JohnRR

Re: 440 vs hemi ? - how do the blocks differ? - 09/07/10 01:13 PM

Quote:

IIRC

a HEMI has 5 bolts around the cylinder and cross bolt mains.

a 440 only has 4 bolts around the cylinder..

No , all big blocks have 5 bolts around the cylinders , smallblocks only 4. the inner row of bolts is up higher and slightly offset between the wedge and the hemi .

Posted By: JohnRR

Re: 440 vs hemi ? - how do the blocks differ? - 09/07/10 01:18 PM

Quote:

Hemi heads will bolt onto a 440 block except for the bolts along the lifter valley. The Hemi intake ports sit right over those holes so they moved the holes into the valley an extra 1/2 or so to allow the bolts to be accessed from underneath. In effect the 4 bolts (studs) in the lifter valley go up into the bottom of the head while all the others go down through the head into the block,these studs are threaded into the intake ports and need sealer on them.

Also the lifter valley had a deeper groove cut into it to allow the intake pushrods to miss the block since they were at a different angle. There are separate holes thru the deck for the exhaust pushrods.

Lastly the corners of the Hemi heads had drain tubes to let the oil drain back into the oil pan. The 440blocks have no provision at all for the drain tubes.

The other differences are the 4 bolt mains and the original hemi has no mounting ears for motor mounts. They use flush mounted motor mounts. Some current production blocks have both.

This pretty much sums it up , I expanded further on a couple of the lines ...

Posted By: B5 Bee

Re: 440 vs hemi ? - how do the blocks differ? - 09/07/10 02:58 PM

Hemi block is drilled for a 1/2" oil pick up tube, 440 uses 3/8".

Because of the heavier main caps, thicker main bearing saddles and extra material at the blocks corners to allow for the oil drain back holes, Hemi block weighs more, not sure how much, 40lbs?

Posted By: Mopar_Mike

Re: 440 vs hemi ? - how do the blocks differ? - 09/07/10 04:26 PM

So there is such thing as a "440-Hemi" Where can I git me one of these?

Posted By: nutso suave

Re: 440 vs hemi ? - how do the blocks differ? - 09/07/10 04:54 PM

thanks again, very informative...i knew they were similar but not interchangeable. here is a link to the 440 hemi heads...i might have to get me some. how do these stage V hemi heads compare to aluminum eddy heads? do you have to buy a special intake from stage V or will any hemi intake bolt on?

linky: http://www.stagev.com/pages/hcheads.html

Posted By: IMGTX

Re: 440 vs hemi ? - how do the blocks differ? - 09/07/10 05:02 PM

Over the years there have been multiple conversion kits. Some for Big Block Chevies (not even close to mopar parts in that kit.)

I remember a 383 done in a car mag back in the late 70's early 80's. They added a tube along the side of the block for the oil drain back and did a few other changes to accommodate the valve train.

As long as you don't break a part then you were OK but if a unique part breaks and the company is gone your in trouble.

IF you can find an aluminum head (aluminum fixes pretty easily) that uses stock valve train it would be OK. For me it will be the day after the company goes out of business that a no longer available rocker arm would break.

Posted By: JohnRR

Re: 440 vs hemi ? - how do the blocks differ? - 09/07/10 05:08 PM

Quote:

thanks again, very informative...i knew they were similar but not interchangeable. here is a link to the 440 hemi heads...i might have to get me some. how do these stage V hemi heads compare to aluminum eddy heads? do you have to buy a special intake from stage V or will any hemi intake bolt on?

linky: http://www.stagev.com/pages/hcheads.html

You still have to get a custom piston and a longer set of rods. There is another thread on this, it's maybe 10% cheaper to do it this way and in the end you still end up with a weaker lower end . Other than the head and special stage 5 rocker assembly it uses all other hemi specific parts.

Posted By: nutso suave

Re: 440 vs hemi ? - how do the blocks differ? - 09/07/10 05:28 PM

Quote:

As long as you don't break a part then you were OK but if a unique part breaks and the company is gone your in trouble.

IF you can find an aluminum head (aluminum fixes pretty easily) that uses stock valve train it would be OK. For me it will be the day after the company goes out of business that a no longer available rocker arm would break.

no doubt!

JohnRR -

interesting...it seemed like you could just bolt them on by reading the website. it would just be cool to have a 440 hemi.

Posted By: imfixinmopars426

Re: 440 vs hemi ? - how do the blocks differ? - 09/07/10 05:39 PM

one is 150-200 bucks,and the other is 3000-skysthelimit!..

.but i bought a block at indy a few years back for 600..yep a 426 1966.

Posted By: JohnRR

Re: 440 vs hemi ? - how do the blocks differ? - 09/07/10 05:44 PM

Quote:

JohnRR -

interesting...it seemed like you could just bolt them on by reading the website.

I think that's what many think because you see this question time to time . These had had their time before Hemi blocks became readily available .

Posted By: Pat_Whalen

Re: 440 vs hemi ? - how do the blocks differ? - 09/07/10 06:02 PM

Quote:

thanks again, very informative...i knew they were similar but not interchangeable. here is a link to the 440 hemi heads...i might have to get me some. how do these stage V hemi heads compare to aluminum eddy heads? do you have to buy a special intake from stage V or will any hemi intake bolt on?

linky: http://www.stagev.com/pages/hcheads.html

From their webpage:

Quote:

The intake port openings on all Conversion heads are 10% large than stock for enhanced breathing and stock Hemi manifolds bolt right on.

Posted By: nutso suave

Re: 440 vs hemi ? - how do the blocks differ? - 09/07/10 06:05 PM

it started over in the general forum, about making a 383 hemi, and then i just got curious...i think the eddy packages are pretty unbeatable for bolt on power value. i'd just love to see some self professed expert's face at a cruise-in when i showed him my 440 hemi.

edit:

Quote:

From their webpage:

Quote:
The intake port openings on all Conversion heads are 10% large than stock for enhanced breathing and stock Hemi manifolds bolt right on.

i read that, but i wasn't sure if it was exhaust manifolds or intake or both.

Posted By: JohnRR

Re: 440 vs hemi ? - how do the blocks differ? - 09/07/10 07:38 PM

Quote:

i'd just love to see some self professed expert's face at a cruise-in when i showed him my 440 hemi.

All you have to do is bore the 426 block .070 over , it's 440 cubic inches ... but I get what you are saying.

Quote:

Quote:

From their webpage:

Quote:
The intake port openings on all Conversion heads are 10% large than stock for enhanced breathing and stock Hemi manifolds bolt right on.

i read that, but i wasn't sure if it was exhaust manifolds or intake or both.

Both , BUT I don't think stock exh. manifolds clear the wedge mount ears , at least on the driver side .

Posted By: fig426

Re: 440 vs hemi ? - how do the blocks differ? - 09/08/10 07:24 PM

How much does the conversion kit cost?

Posted By: JohnRR

Re: 440 vs hemi ? - how do the blocks differ? - 09/08/10 07:42 PM

Quote:

How much does the conversion kit cost?

over 5k

Posted By: HotRodDave

Re: 440 vs hemi ? - how do the blocks differ? - 09/08/10 07:49 PM

In theory you could run the same piston as a stock 440 but compression will be extremly low.

Posted By: JohnRR

Re: 440 vs hemi ? - how do the blocks differ? - 09/08/10 07:53 PM

Quote:

In theory you could run the same piston as a stock 440 but compression will be extremly low.

Do you think it would have enough compression to even start? You will have a cylinder with about 90cc more volume, then there is possible piston to valve clearance issues considering valve notches aren't anywhere even remotely in the right place ... but it's a nice thought ...

Posted By: HotRodDave

Re: 440 vs hemi ? - how do the blocks differ? - 09/09/10 01:17 AM

I am not recomending doing this, just saying it could be done. My lawn mower runs on something like 5.5 to 1 compression. Normal 440 pistons sit at or below deck, the valve notches in a hemi piston do not genneraly extend below deck, normally only for the really big cam ones. If for some crazy reason you were forced to run that rediculously low compression sort of deal an ideal cam would not have valves opening more than a few thousands at TDC.

Again I would never recomend anyone do this, just saying you could, but it will be a very weak motor.