Simple flathead HP ideas.? What do you guys know :)

Just doing some research here mainly.
ive worked with standared V8s but, I have found a Good V8 flathead from a 49 model vehicle and i admit to knowing little about them..
If i read right stock is about 100HP.
I dont want to get to carried away with building it, and do not wish to invest a ton of money on speed parts & machining if possible.
So what can i buy or do that is cost effective to produce extra HP maybe say an extra 25 to 50 HP...So what do you Experts have to say

thanks all

 

Check the tech archives for a post called "Flathead 101"

 

Thank you Flathead Ernie

 

Headers are the best bang for the buck! The stock manifolds work like restricters, I've had nearly 20% increase in power with just headers!!

 

Ok Headers Seem logical enough

Thanks Irishpol

 

A mild cam will improve things dramatically. If you're rebuilding the engine anyway, put a little lope in it.
I second the header suggestion, anything to improve the flow.

Flatman

 

ok Cam Check..any recomendations on cam size.?

 

The selection isn't huge out there but there are a few to choose from. I used an Isky Max 1 with adjustable lifters. It gets good reviews from people on here for street applications. Isky 400JR is also popular, but I hear it idles rougher than the Max 1.

Flatman

 

Don't buy anything for it until you do some homework. check it out. I assume that you are going to rebuild it mentioning cams and such. Many of those engine look good and may even run good but are not suitable for a rebuild. Also, Be aware that even a stock rebuild is going to cost much more than most other engines. Best thing you can do is READ everything you can about the engine. You will either give up or become a flathead GURU

 

Guys that run flatheads are not, for the most part, all that into gobs of hp, if they (we) were, there'd be a big block in our rod. A flattie will look good, and run great, with a set of aluminum heads and a dual carb setup. Headers, of course. A mild port job, especially in the end four exhaust ports, and the above add-ons will give you 150 horses or thereabouts without hurting the reliability or driveability. Put it in a 1700 pound car (or less!) and have a ball!

 

Thanks all you guys

Theres a story behind the car and motor.
but the motor when it was parked still ran., the water was drained from it and the motor its self was ran while oil was pour down the intake and drowned out, it set that way untill about 10 years ago when it was started again, ran for a few min then drowned again. and has set that way since.

i hope the motor is still buildable, but it is anyones guess...

 

have the block checked for cracks after you tear it down & before you spend any dough

 

Ya definitly not going to invest in stuff till i know its good

 

Once you find out if the block is good, getting another 25 hp shouldn't be too hard. Increase the compression with aluminum heads, add headers, and help it breathe with either a 4 barrel intake or something for a pair of holleys or strombergs. A stock cam will probably get you where you want to be but won't sound as good as one with a little lope.

Neal

 

I'm only starting to learn about my flathead BUT I drove 300 miles each way last week with my FH in the back of my minivan to spend a day with a GURU. We poked and prodded at my mill with dial calipers, dial indicators, feeler guages and plastiguage, we pulled a piston, took all the rings off, checked ring gaps, pulled a valve, looked at the oil pump to cam gears, pulled the cam gear, measured end play etc. He said I'd get 25% increase in HP by polishing the vales stem/head area, adding headers, matching the intake manifold port opening to block intake port area, and I'd run cooler by cleaning up the casting area inside the exhaust ports. All stuff the factory should have done given a little more time. Apparently if you add a cam without opening up the combustion area above the valve you're wasting your time. Also indexing the spark plugs (opening facing intake valve) will greatly increase starting and efficiency. ALSO I'd recommend if you haven't one already to build an exhaust port mounted engine stand head...

 

Ford had factory ported and relieved blocks for military applications etc ( I worked for a military vehicle collector and I often came across these in Bren gun carriers)But the hot set up I've learned is to just relieve the block around the intake valve only because you lower the compression ratio too much with a complete exhaust and intake relief.

I also think a lot of work can be done to lower the quench area volume in the cylinder area of the head . The original design Ford combustion chamber in the heads is a bit old fashioned and can benefit from some modern thinking in terms of quench and turbulence.
you cant go past stock Ford cams when you are building nice every day driver flathead. I always ran 46-48 truck cams, I 'think" the factory designation was 3TA or 5TA. These gave plenty of low end torque and vacuum with lots of revability. I always ran twin or triple carb setups wth 94's with great results.
by the way,it's not power you are seeking with a flattie... it's Torque.

 

I am just finishing up a rebuild of a '50 flathead. I have an engine dyno and tuning session scheduled for tomorrow. I'll try and post the engine specs and results Saturday night or Sunday morning.

Todd

 

Everything that has been mentioned is valid-in terms of increasing horsepower, which is what you wanted to know. Keep one thing in mind however: All "Horsepower" adders tend to be R.P.M. sensitive i.e. cams, porting/polishing, multiple carbs, and other flow improvements-you gotta run it harder to take advantage of them.. The quick & dirty way to seat of the pants "grunt" is all the displacement and compression you can cram into it. And you don't necessarily need aftermarket aluminum heads to gain compression. Stock '52-'52 EAB heads on an overbored stroker will get you all the pressure you need. You may need headers (and exhaust porting) to let it all out. I remember some mighty big (296"-304") sportsman stock car engines from back in the early '50s that ran like jack the bear with a stock Holley 94 and stock heads.

 

Back in the day a chromed air cleaner from Western Auto seemed to give you 10 more HP

 

This is kind of a stupid newb question...but I have an awesome running 8BA in my 48, but it's all original with what the odometer claims is 112K miles. Would I be taking a serious risk by bumping the compression with edelbrock or offy heads without doing a full rebuild? I'm just kinda going for looks.

 

. I remember some mighty big (296"-304") sportsman stock car engines from back in the early '50s that ran like jack the bear with a stock Holley 94 and stock heads.[/quote]

Hey Dale, Wasn't that cheating????

 

How is it running? If it has good compression, not using oil, go for it.

Neal

 

In my area (Lima, OH) the rules said"stock to the eye." Anything you could stuff in there was legal. Headers were allowed.

Hey Dale, Wasn't that cheating????[/quote]

 

Thanks for all the Info Guysits given me alot to think about.....i'll know more sunday

 

you probably already know about it, but check out www.speedwaymotors.com for street rod stuff. they got a great offy dual carb flatty intake for $200, plus steel tubing headers for $130. another MAJOR thing to look at is the ignition. think there is an article on here about adapting a mopar distributor to a flathead that got some great results for not a whole lot of money.

 

You said simple Flathead horsepower ideas. I'm assuming this engine will be apart, right? My humble opinion.....do this.....

http://lonestar.texas.net/~mcdaniel/porting.pdf

Won't cost you much and will be a good lesson in airflow which is priceless.

When you get it together get a decent ignition sytem on there with 12 volts.

The rest is just fundamental engine building. I would'nt worry about multiple carbs to keep it simple. An old stock car racer told me that a 4- bolt Merc intake will accept a Rochester 2GC and he say that'll give you a nice bump in the ass. I'm taking his word for that though since I've never tried a 2GC myself.

This is some fun reading too.....

http://www.midstateantiquestockcarclub.com/flat_heads1.html

 

GMC BUBBA makes one from a Chevy 350 distributor. Full mechanical advance, no vacuum problems with multi carbs. Ready to drop in and run.

Flatman

 

J. Infante

Ive looked for the Distributor articel and cannot find it, would anyone with a bit more knowleadge mind thowing me a link...sorry to bug you all

 

Where is the best place to buy FlatHead Headers?

 

http://www.btc-bci.com/~billben/flathead.htm

This site has much information for the flathead. Priceless!

To find the info on adapting a chevy distributor, go to hei distributor conversion.

I did one a year ago. Worked well until the engine went south.

Neal