* IRON BLOCKS ?
2/27/08 UPDATE:
Well the new Mopar blocks from World Products are here, and the look
great. Call and talk to Angie to get the full low down. Finally there is a
"good" source for these iron block - and aluminum too. We still
like the KB option best for aluminum.
8/01/07 UPDATE:
Well you may have seen the Mopar ads for new iron and aluminum blocks.
These blocks are totally different from what Mopar was making before. The
new blocks are made by World Products. Their term CGI stand for
"Compacted Graphics" and should result in a stronger casting.
But these blocks are just starting to roll out. Time will tell.
3/20/07 UPDATE:
Well we are starting to see the light. We are getting deliveries of iron
blocks from Mopar again. These are few and far between, but they are
coming in. Casting quality seems to be okay. Blocks on EBAY are
still going for big $.
1/5/07 UPDATE:
The situation has gotten worse. There are a few blocks being made but
Mopar is using those to fill crate motor backlog. Good iron blocks are
going on EBAY for up to $5K (might as well buy a KB). Rumors say that
Mopar is changing vendors and something "will be done" but who knows
how long that will take. SORRY!
09/01/06 UPDATE: We are
getting deliveries of the iron water (non-siamesed) blocks and they are coming
through okay. The typical stroker HEMI using this block and a 4.15
crankshaft is 471".
10/3/05:
MOPAR is shipping iron blocks. Whew !!! What
a hassle that has been. The Mopar water blocks (non-siamesed) are coming
through fine, but the siamesed bore blocks have had a lot of core shift - you
should be
prepared to pay for sonic checking every block!
We have built HEMIs using the new water blocks, and with a 4.15 crank, you get
471" They have all been fine. But we're staying with the KB aluminum blocks
unless you specifically want an iron block. Most of our customers are okay
with the higher cost of these blocks.
But there are some good reasons to consider an iron block:
1) The KB blocks require external oil lines and the longer oil pump may require
grinding the K-member. This can cause installation headaches if you
have a car with a normal K-member, motor mounts, headers, etc. The KB
blocks are designed for big stroke crankshafts which would not work with an internal oil pickup.
2) The external oil lines can interfere with street type headers. Almost
all our customers have rerouted the oil lines after engine installation in the
car.
3) There is no provision for a
mechanical fuel pump (electric pumps are better anyway).
4) Aluminum expands more, so mechanical valve lash must be set hot.
Hydraulic cam lifters need 1/2 turn more preload.
5) Bearing clearances are tighter on a cold engine, so aluminum motors must be
heated up before high RPM operation.
So if you're
okay with a smaller displacement HEMI, with a nominal 3.75 to 4.15 stroke, and
with an internal oil pickup, then the iron block is fine.
Consider
a Keith Black aluminum street HEMI block.
We
have built many of these motors using these blocks. Here's the pros and cons:
PROS:
* They weigh only 140 lbs. A 572" KB HEMI weighs LESS than a 440.
You don't even need to change the torsion bars.
* They can handle 2000 HP. Yes - they're stronger than an iron
motor. The street HEMI KB block is a full water block, but still it's strong
enough to handle severe racing applications.
* These are STREET blocks. In other words they carry water, work with
almost any water head, cool great, can be configured for normal motor mounts,
etc.
* The DON'T leak. The fear has always been that aluminum blocks leak water
around the sleeves. Well, the new aluminum blocks DON'T LEAK! KB and INDY
have spent a lot of
time and R&D $ figuring out how to keep their blocks sealed, and they solved
it years ago. It's a combination of design and assembly techniques
but IT WORKS!
* They
can be fixed. This is a minor point because you shouldn't be
"fixing" a block, but aluminum is repairable, whereas cast iron is
not.
* They are available, built to order, and require minimal machining once we get
them.
* They look great.
CONS
(see also #1-5 above in green):
* They are more expensive. But not as much as you might think when you
consider that a $2300 (approx) Mopar block requires about $800 of machining
before we can use it. So the actual price increase is about $2500. If
you're spending $25K to $50K on you car (often A LOT more), and then another
$17K or
so for the HEMI engine, does the extra $2.5K really squelch the entire project?
* There is no provision for an internal oil pick so all oiling must be
external. This is better anyway since stroker crankshafts always hit the internal
pickups and external systems flow more oil. (Note the double main cap
cross bolts in the picture.)
* The is one motor mount hole on the drivers side which had to be moved because
of the superior oil galley that Keith Black casts in the block.
* (4/16/04) Okay, okay... We have had several emails from people that feel
there's another "con" we need to mention if your building an all out
race motor. Everything else being equal, the aluminum motor will make a
little less horsepower. We have seen as much as 20 HP, on the dyno,
on 900 HP motors. This is because the engine is basically an air pump AND
a heat engine, and it's harder to keep heat in an aluminum motor. Also, aluminum
moves around more, so ring seal varies at very high cylinder pressures.
But this only affects all out race motors. On a street motor it would be
hard to measure any difference, and any slight decrease in HP would be more than
offset by the decrease in weight.