What can be gained by a 6.0 head?

[ETAModel]

I have a bone stock 30 Fordor. If I went with the 6.0 head, how much of a power increase would I see? I'm talking about using existing carb. I don't want a radical alteration.

Thanks.

I apologize if it's been covered before.

[PC/SR]

I have a 6.0 head and a B cam. The power increase is noticeable and handy to have for going up hills and a more accelleration which is good at stops. I do not believe the head without the cam would be much less. You would feel the difference, but this is not radical. If you worry about it get the 5.5 head. Dont worry about the babbitt. I have a speedster with a 7 head for hillclimbs and people run serious races at Bonneville on babbitt.

[BRENT in 10-uh-C]

Originally Posted by ETAModel

I have a bone stock 30 Fordor. If I went with the 6.0 head, how much of a power increase would I see? I'm talking about using existing carb. I don't want a radical alteration.

Thanks.

I apologize if it's been covered before.

In a nutshell, probably about 5 horsepower, -or around a 10% increase. While you likely will notice the increase, it will be negligible. To take full advantage, you need to increase the air-flow to compliment the entire package. As mentioned above, a better camshaft in conjunction with the 6.0 head will likely seen gains of 8-9 horsepower, ....and add a larger intake manifold and the 3 as a package will likely see an increase of maybe 12-15 horsepower. At this rate, the torque is also increased which you will definitely notice in the seat of your pans when driving.

[Gene F]

Torque is where ya really seem to feel the change. Just my opinion.

[chap52]

Ain't real technical but I could notice a power difference. I had to retrain myself for timing adjustment settings. Chap

[29spcoupe]

Sponsored Links (Register now to hide all advertisements)

According to the dyno sheets my stock engine with a 5.5 head, Model B carburetor, bored out manifold and aries muffler, I get 55 horsepower. The increase is noticeable with less shifting.
John

[Bruce of MN]

Staying in 3rd while going uphill is a big difference.

[1931 flamingo]

Bragging rights. 35mph is still 35mph. Paul in CT

[Keith True]

I have three Brumfield heads.To tell the truth I don't know if they are 5.5's or 5.9's.I would prepay for one,and when a blem came up he would ship it to me.I did that three times.The difference to me is climbing the hills,running cooler,and fuel mileage.

[Big hammer]

I’ve had people follow/chasing me around town, when they finally caught me or I stopped, they commented that thing really scoots! I couldn’t catch you. 6.0 head, 330 Stipe’s cam, stock intake, Zenith carb. Shifting into 2nd @ 8 mph, 2nd OD @ 15 mph, 3rd @ 30 mph, 3rd OD @ 40 mph. If your one that lugs your stock A, don’t put a higher compression head on ! Lugging = 20 mph in 3rd gear

[old31]

Go with the 6.1, you will never look back. Better hill climbing, better take off at lights. I can not say that my mileage is better.

Some say you should take the new head to a machine shop to have it checked for flatness.

[Flathead]

If your motor is in good condition and tuned right you should feel a noticeable increase over stock. Don't lug it and it will not want as much timing advance as stock.

[ETAModel]

The only time I drive 35mph is in town and on curves. If I was happy with topping out at 35mph I would've bought the Model T Phaeton I test drove 20 years ago.

I understand it's a 40 horse motor, 90 year old technology, and comes no where near my '19 F150. I'm looking for a little more Umph because all my driving has been on mostly flat ground, and I want to take it to Breckenridge Colorado to hang out with family.

Ole Edgar will do 50mph easy, here in Texas. What I don't know is how he'll do at 10,000 feet. A 6.0 head seemed much easier, and cost efficient, than other options.

Btw, I would be thrilled with Ole Edgar going thru the Eisenhower Tunnel or Hoosier pass at 35mph. But not on flat ground.

[nkaminar]

As we all know, the gasoline in 1930 was very low octane. The Model A was designed to burn this fuel without knocking. It is now almost 2023 and gasoline has gotten a lot better. The higher compression head makes a lot of sense. It will help with the torque, fuel economy, and better cooling, as Keith True said.

However, to get more horsepower it is torque plus rpm. To get the rpm you must improve the breathing, which means a larger carburetor and manifold and a better muffler.

[ETAModel]

I want to thank everyone for your response. I'm still wrestling with the decision.

[Bob Bidonde]

My Victoria has a 6:1 head, and the difference in performance is noticeable. Acceleration increased, so it is easier to keep up with traffic around town. Highway gas mileage is up to 23 mpg with 87 Octane gas. The higher compression necessitates less spark advance to avoid engine knocking.

The steering column spark advance quadrant in my A's have 12 notches. Timing the ignition the stock way only allows the use of 5 or 6 notches down with the 6:1 head. So when timing the ignition at TDC #1, I pull the spark lever down 5 notches then set the cam to just begin to open the points. This gives me the full use of the spark advance quadrant.
You will need to operate the spark advance lever as opposed to just leaving it all the way down with a stock head. I only go all the way down when cruising on the highway. Around town I set the spark lever halfway down.

[Gene F]

I have a high compression head, and the IB-330 came, etc. I operate my spark much like Bob does.

[Synchro909]

My comment embodies what others have said one or two things at a time.
To get an engine up and marching, I say there are 3 things you should do. They are the three "C"s - carb, cam and compression. You (OP) say you don't want a radical change - I assume that means you don't want it to look like a hot rod under there.
By my experience, a 6:1 head is a PITA. You have to play too much with the timing as you drive around town but it's OK on the open road. I'd go for the 5.5:1 head or a distributor with auto advance. That's the compression "C"
As for Cam, I'd put in a B cam or something not too radical. I'm not familiar with what is available over there but I have my original cam reground for a bit more duration.
As for the carb "C", there are to components. I'd bore out the inlet manifold to B specs (I did mine with a burr in the pistol drill) and fit a B carburettor. To someone who knows his Model As, that would be noticeable but it wouldn't jump out at you.
So, now you have an engine that looks bone stock from the outside apart from the carburettor, is very driveable and will get up and boogie without you having to be constantly fiddling with the timing.
I have an engine like that and it has towed a camper trailer weighing about a ton for about 45,000 miles (with O/D) at 50 mph and many thousands of miles solo car. It is still going. Admittedly, I beefed up the bottom end with pressure oil feed to the middle main bearing, counterweighted crankshaft and a couple of other things but I don't think you need worry about them. What I'm saying is, you will still have an engine that will go the distance. I estimate my setup is good for 60+ HP while retaining flexibility.
By now you are probably feeling a pain in the hip pocket. Which would you prefer - a few dollars still in your pocket or a big grin on your face. Horse power doesn't come cheap - never has.

[Flathead]

Ford did offer a "Police Head" that was 5.5 compression ratio. They were very careful to only let those heads into the hands of law enforcement, there was much frustration by the general public however.

[alexiskai]

Police Head, aka the "B" head, was 5.2:1.