Thread: Flathead Newbee Needing Direction!

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Hey I do not actually know how much the setup in that '34 cost, but figure if it has the conversion to a C4 trans that is at least $1500 (about what a 700R4 would cost after some modification) that is about the same as a SBC setup but I am not sure you can adapt a flathead to a GMC transmission so you might have to include the C4 conversion in the cost.

C4 kit $1250
triple intake $260 (8BA)
Isky cam $244
Stromberg97 $150 each x 2 or 3 ??????
Heads $440 (Offenhauser as in Picture)
Pistons $275 (three ring)
Rings $120
Bearings $ 95 (8BA)
Oil Pump $128
4" crank $896 (new, $500 from me)
water pumps $ 90 each, need two
distributor $400 (8BA) Mallory dual point
chop flywheel$100?
Headers $130
Hot Coil $ 30
Main Supports$ 40
Adj. lifters $140
Valve guides $ 56 (set of 16)
valves $160 (stainless, optional)
springs $ 60 (single)
etc. ........ $_?????_______________
Est. Total $5454

Machining block, boring etc. $ 12/hole x 8 = $96
Porting & Relieving??????? Guess $500

Block ???????????????????????????????????????

That is a rough estimated of cost using prices from the Speedway catalog. Stainless valves are an option and I forgot the hardened valve seats or a three angle valve job. The point is that things are a little more expensive for the flathead than for a SBC rebuild which I think can be done nicely for about $1500 so that is some idea of the costs but the main problem is still finding a good block!

Don Shillady
Retired Scientist/teen rodder

thats about twice as much as i got in my sbc 350 right now. i mean it is alot but if you build it over time it can be done. i took me a bout a year and a half to buy all the bullet sutff for my sbc anyway. All the crome and bullet parts cost me more than building the long block did ! I would say 2 to 3 times more, and im still changing parts. so i figure if ! and i mean IF i find a good block i think i will try it, hey if i can't at least im sure i could get my money back.

It sounds as if you are determined to try to build a flathead so go to it. The point of the cost analysis above is that after all that expense to get somewhere between 200 and 250 HP, it can be compared to an inexpensive 350 SBC which gets 270 to 300 HP. Of course you can spend more on the SBC but nostalgia is the operative effect here and would be fun if only it were easier to find a good flathead block. One thing that might be worth planning on is to change over to hardened valve seats since the flatheads were build for leaded gas. Here is a link to a car/engine based on a flathead. The pictures are interesting because they show the reliefs ground into the block between the valves and the cylinders, that is a rodding trick, not the stock surface of the block.

http://www.34hotrod.com/HotRod/page7.htm

Don Shillady
Retired Scientist/teen rodder

Anytime you build an engine outside the normal sbc or sbf area, you are going to spend more. I could have built 3 Chevy small blocks for what I have in the 394 Olds in my '39 Dodge, but the wow factor makes it worth it.

I only mentioned the cost of building a flathead so you go into it with your eyes open. Also, finding a suitable core to begin with is tough.

Good luck.


Don