Flatheads!!!

Hello all, I am researching my engine for a rat build. I want to go flathead and was wondering what I should look for in an engine. I want the most horsepower I can get, what year make and model should I look for? What are some HP numbers with lets say a rebuild, cam, 3x2 carbs headers. Is the mercury engine the same as the ford? What has the best aftermarket parts available. What should I pay for a stock engine that is running or can be rebuilt?

Thanks
MG

Moregunzz said:

Hello all, I am researching my engine for a rat build. I want to go flathead and was wondering what I should look for in an engine. I want the most horsepower I can get, what year make and model should I look for? What are some HP numbers with lets say a rebuild, cam, 3x2 carbs headers. Is the mercury engine the same as the ford? What has the best aftermarket parts available. What should I pay for a stock engine that is running or can be rebuilt?

Thanks
MG

Click to expand...

Short version.
1946-48 59A or 1949-53 8BA engines
Stock. 110HP max. Hopped up-$$$$$=HP.
Mercury has a bigger crank but lower compression heads. The Merc cranks are sought after for use in stroking the Ford blocks.
Many aftermarket parts are available as well as original stuff. Use a reputable source and you will be fine.

Running stockers are priced all over the map. Usualy around $650 to $2000 or more.
Having a stock flatty rebuilt for you can run around $5000-$6000.
If you do it yourself it will be less.
Here's the hard part. These engines blocks were prone to cracking. Mainly between the valves and the cylinders. But other areas as well.Most that are cracked are not rebuildable. It is not unheard of to tear apart 5 engines to find one that is rebuildable. The first thing that you will have to do is to pull the heads and do a visual inspection for cracks.
Google Vanpelt LLC. He has a great wealth of flathead info on his site as well as parts for sale.
Hope this helps.
Torchie.

Flatheads

The first this to say is a well built flatty has a sound all of it's own, and when done right they look better than the wife's diamond rings, and cost more also !!!
I started with a good block from my 49 no cracks, I just got lucky! it did have a few rust spots from water sitting in the cylinders, sent it to a good friend and old time machine guy that did flatty's back in the 60's, bored it to 125 to clean up all the spots, worked the entire block. line bore, hardended seats, cam bearings ect. I purchased a good 4" merc crank, 10-10 cleaned it right up, new pistons, balanced everything, shot peened, relived the top of the block around the valves, he polished out and worked the intake and exhaust ports, all new valves, springs, guides, locks, lifters ect. new oil pump, water pumps, gaskets and seals ect. I sent my stock cam up to wash. state. and had it reground, I opted out of the alum heads, and found a good set of merc. heads, I may still go alum. used intake manifold and old carbs, all the parts to set up 3 carbs, all rebuild parts, new shafts, power valve for 1 and plugs for the others, new shafts and plates, primary and secondary, I can put it all to geather so no cash out of my pocket there, after it's all said and done I hope for 175 to 185 hp. so I get an extra 75 to 85hp over stock, and it only cost me about $4000.00
Now if you want to get over the 200 hp range you need to put a blower on top of it, it will only pull in so much air on its own, and to make power you need more air, so add another $4000.00 and you can get over the 200 mark, now put a t5 set up behind it with a 4:11 rear end $1500.00 and you will have a traffic light screamer and interstate cruiser that will take out most of the kids on the road today, and some old muscle cars, they will scratch there heads wondering how you beat them.

I do love flatheads.

I have 2 Mercury 255 engines with transmission for sale. If interested I can give you more details.

Hello Gunz. I have a stock Mercury 255 in a '36 Ford truck and it has nice power for cruising up to 70 miles an hour, anyway. I never tried to see how fast it will go yet. That 70 MPH was with a four speed, and now I've put a T-5 in there but have not tested it. If you want to race or spin your tires a lot you probably will have to tweak your motor a bit, but for general driving, city or high-way the flathead will be O.K.. I've been lucky finding Flatheads; only one has been cracked and three or four have been good. Good Luck.

I'd say unless the build absolutely shows off the flathead and it is necessary for "the look", I'd skip it... You will spend more money building a flathead to make less hp at the end of the day...
Just my take on it...

Dirtyrat said:

I'd say unless the build absolutely shows off the flathead and it is necessary for "the look", I'd skip it... You will spend more money building a flathead to make less hp at the end of the day...
Just my take on it...

Click to expand...

Well definately not the biggest bang for the buck DR. I have a nailhead that was the original engine of choice for my project when it was still in the "No hood" stage. Just to pretty to hide so someday it will go into a T-bucket.
There is a guy near by me that is retired and all he does is rebuild small blocks. I could buy one rebuilt from him for about the cost of just machine work on a flathead.
But like old Harley's. And stock engine vintage boats and vintage Brit sports cars, a flatty does have a sound all it's own.

Here my 1948 59AB in my 34

I have a flatty that I purchased from and old hot rodder a while back and now have the parts to go with it to make a "dry lake racer." I can do the disassembly/reassembly work. Is there a GOOD reference book out there that will help a guy out? Thanks!

Try "Rebuilding the Famous Ford Flathead" by Ron Bishop.
Also join the Ford Barn site. Lots of great Flathead knowledge on that site and they don't care if you are hot rodding a flatty of going stock.
You will need a few specialty tools and there are a few quirks that you will learn about. Such as the correct way to mount a flatty on an engine stand.
What year is your engine? Some of the quirks are related to what engine you have.
Post pics if you can and let us follow along.
Torchie.

Thanks Torchie. I will start there!

I got the book. No time to read it yet.

My research tells me that I have a 24 stud motor. Still working on narrowing it down to the exact one.

This will help ID.
http://www.vanpeltsales.com/FH_web/flathead_specs-85to100mid.htm

Thanks for the link dmw. If vanpelts "model" is the number that is stamped on the heads I have a 29A model. They show it as a 1942 Mercury 100 horse. Is this worthy?

Post up some pics of the engine if you can.
The numbers on the heads can be misleading as much of the flathead stuff was interchangeable. Seen more than one old flatty with unmatched numbered heads that ran just fine.
Merc motors and heads actually have lower compression than their Ford counterparts.
The value in the Merc motor over a Ford flatty is the internals as this is what the old timers used to bore and stroke a Ford flathead.
Plus the only sure way to identify a Merc crank is to mic it.
But any running Flatty has value regardless of it being a Ford or a Merc.
Torchie.