4.1 crossflow, Iron head. Transmission options

JTHooperg3

New member
I am looking at an Iron head 4.1 crossflow, this will go into my 63 mercury comet. Currently I have a 200 and c4. I was told the c4 will bolt up as long as I use a drop down cable or make a linkage. I plan on running either Webber’s or a single Holley HP 500cfm 2300, crow cam with full updates, lifters/pushrods/springs/etc. an Aussie speed manifold. This is a non emissions vehicle. Is there any other parts suppliers I should look into?
 

rocklord

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Welcome to the forum.

If you need to rebuild the iron head, you may want to upgrade to the aluminum head. If your interested, I have one In the US that needs rebuilt I would sell.

Just let me know.
 

CNC-Dude

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You didn't mention if you are planning to use a US engine block or not, and were you aware of the mods required to install a crossflow head on a non-Aussie block.
 

JTHooperg3

New member
This is an Aussie motor. My biggest question is carburetors, what have the experienced guys found for pros and cons, I plan on running a crow .510 lift cam with there springs, retainers, push rods, roller rockers etc. Aussie speed intake, Holley 500cfm 2 barrel. This is on an iron head engine with a c4. I’m experienced with Holley carbs, from my dirt modifieds I had, but I love the look of the dcoe Weber’s.
 

CNC-Dude

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There are several good online CFM calculators to determine how large of a carb you'll need to select. A 500 CFM carb is likely going to be too large even for the most radical 200 cubic inch engine. A 350 CFM may be closer to suiting your needs more closely.
 

CNC-Dude

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Because Weber's will have to be reduced in size on their venturies to be adequately tuned and sized. Just because their are 3 of them doesn't mean that their combined CFM needs be beyond the requirements the engine can consume. You would likely use 40MM carbs, but the chokes would end up being much smaller possibly around 36MM or less when they end up being properly tuned.

Sidedrafts are cool, but now consider you have 3 carbs to do the same job that one can do. And now require 3 times the air jets, fuel jets, choke housings, main jets, etc. Instead of just fuel jets for the Holley. Plus a lot of patience to sync 3 carbs.
 
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