Burtz Engine

[rfitzpatrick]

What is the rated horse-power of a stock built Burtz? What other Chassie modifications should be considered?
Thanks

[Synchro909]

A stock built Burtz engine will give he same power as a stock built original engine. Stock head, cam, carburettor = standard power. No chassis modifications are required because it has exactly the same external dimensions as the original.
The thing about these engines is that they are many times stronger in the bottom end and so, are capable of being "breathed on" to get more than a standard engine would be able to do with any sort of durability and they do it without the vibrations you'd get with an original.

[Kurt in NJ]

the bearing area is about equal i figure, building oil pressure takes some power,
The head,cam lifters,valves pistons and all external parts the same
exactly the same cam timing

I suspect it would be about the same , with the variable of being at minimum clearance versus maximum clearance , balance at optimal numbers or at opposite limits

[ModelA29]

I think there are 2 ways to answer this question. If you build the engine with an original cam and compression ratio you should expect original horsepower. But if it's built with Terry's cam and higher compression head I'd expect an increase in horsepower. Has anyone put one on a dyno with Terry's cam and head then published the figures?

[Terry Burtz, Calif]

Originally Posted by Kurt in NJ

the bearing area is about equal i figure, building oil pressure takes some power,
The head,cam lifters,valves pistons and all external parts the same
exactly the same cam timing

I suspect it would be about the same , with the variable of being at minimum clearance versus maximum clearance , balance at optimal numbers or at opposite limits

There are huge differences in bearing area between an original engine and the new engine.

The bearing area in an original Model A engine has 3 mains at 1 5/8 inch diameter, and 4 connecting rods at 1 1/2 inch diameter.

The new engine has a much stiffer crankshaft with more bearing area because it has 5 main bearings at 2 inch diameter and 4 connecting rods also at 2 inch diameter.

[nkaminar]

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There is a slight modification to the intake passages to clean up the flow, so there will be a slight increase in horsepower. Not much.

The Burtz engine is strong enough to get some modifications, such as a higher compression head and downdraft carburetor(s). The Ford drive train seems to be capable of handling increased horsepower. If you are driving down a level road at 55 mph, you are using the same horsepower regardless of how much the engine is capable of. Point being, under this condition, there will be no difference in the strain on the drive line components.

[81ls1camaro]

50 Horsepower or so.
https://www.fordbarn.com/forum/showthread.php?t=320985

[Kurt in NJ]

So with a “huge” difference in bearing area and a larger diameter of the journals there would be more friction, and the drag of the oil pump producing 40 lbs pressure compared to 8 lbs pressure (I know the electric drill testing a oil pump output works a lot harder at 40 lbs).
So with everything the same (original stock model A)except for the block,rods,crankshaft would the changes in the intake ports make enough difference to make up for the increased losses due to friction and oil pump load?

[rfitzpatrick]

Yall are really a help -- I thank you.
Now -- I've never driven my '31 PicUp over 45. I get the impression that with the Burtz, I could do more. My 'up-grades': F-1 Ford Steering Box. A 3:54 differential gear. New Radiator. Now would say a speed of 60 be within reason, plz?
TKS

[JayJay]

Originally Posted by rfitzpatrick

Yall are really a help -- I thank you.
Now -- I've never driven my '31 PicUp over 45. I get the impression that with the Burtz, I could do more. My 'up-grades': F-1 Ford Steering Box. A 3:54 differential gear. New Radiator. Now would say a speed of 60 be within reason, plz?
TKS

I would say that if you build up a Burtz engine with some mods above factory (hotter cam, higher compression head) that with your 3.54 rear end you should definitely be able to increase your top speed. More so if you added in an overdrive. At least that's what I'm counting on to justify my Burtz/Mitchell build!

JayJay

[81ls1camaro]

Originally Posted by rfitzpatrick

Yall are really a help -- I thank you.
Now -- I've never driven my '31 PicUp over 45. I get the impression that with the Burtz, I could do more. My 'up-grades': F-1 Ford Steering Box. A 3:54 differential gear. New Radiator. Now would say a speed of 60 be within reason, plz?
TKS

Should be plenty capable of 60 mph. They ran one at enough rpm to be 70 mph(stock gearing) for a considerable time on the run stand. Maybe 3k rpm? Your gearing will only help.

[nkaminar]

I had my heavy Fordor up to 73 when I was not paying attention. There was more to go but that was enough for me. Speed was by GPS, not speedometer.

I have the Weber down draft, 5.5 head, Burtz cam, overdrive (3.0 to 1 in overdrive) and that is it. Oh, and I cleaned up the porting a little, just to make the ports smooth, not to enlarge them.

[Kurt in NJ]

my coupe that is stock except for a B cam easily goes over 60, was clocked by a state trooper at 62 and that wasn’t flat out— I was asked if it was stock, the troops wanted to see under the hood— grungy original look ,obviously stock, he just shook his head and told me to keep the speed down.
I didn’t tell him it would go almost 70
stock 3:78 rear, have driven it all day at 65 in the past

[Synchro909]

Originally Posted by Kurt in NJ

my coupe that is stock except for a B cam easily goes over 60, was clocked by a state trooper at 62 and that wasn’t flat out— I was asked if it was stock, the troops wanted to see under the hood— grungy original look ,obviously stock, he just shook his head and told me to keep the speed down.
I didn’t tell him it would go almost 70
stock 3:78 rear, have driven it all day at 65 in the past

It's that wolf in sheep's clothing thing I like about those engines. A couple of weeks ago I was on a night time rally with a sports car club (I was driving my 1929 Model A Phaeton) when the owner of a high powered, fast British car expressed his disbelief at what he had just seen. It was me overtaking modern cars on the freeway. I smiled to myself and left him scratching his head.

[rfitzpatrick]

I smiled to myself and left him scratching his head.[/QUOTE]

I can't believe you guys drive one this speed. I did hit 45 once and lived to tell about it! Looks like I'll be getting the Burtz, I just got the OK from my Warren.
Now at way method might you break in a new engine such as the Burtz?

[Synchro909]

Originally Posted by rfitzpatrick

I smiled to myself and left him scratching his head.

I can't believe you guys drive one this speed. I did hit 45 once and lived to tell about it! Looks like I'll be getting the Burtz, I just got the OK from my Warren.
Now at way method might you break in a new engine such as the Burtz?[/QUOTE]

Break in is pretty much the same as any other engine. I didn't feel like mine was run in till I had about 1,500 miles on it.
As for running at that speed, There are a few things you should do to make your car handle better. No slack in the steering, good shock absorbers and everything good in the suspension including tyres spring to mind. I also believe the soft rear engine mounts cause the car to feel "vague" on the road. I got rid of mine.

[Jeff/Illinois]

Originally Posted by rfitzpatrick

I can't believe you guys drive one this speed. I did hit 45 once and lived to tell about it!

I was thinking along that same line,,,, 50 or 55 MPH plus in a Model A Ford??? Are you guys nuts Those skinny little bicycle tires on a 90 year old plus car that the chassis and running gear has been metal stressed who knows how many times? Doors that will pop open if you ram them good and hard with your elbow from the inside? Especially on an open top car??

Speed is meant for Mustangs I'll reserve that need for THAT capacity in one of those, thank you very much

[AzBob]

A well sorted Model A is capable of 55 to 60 MPH all day. They were advertised to run 55 to 65 MPH even in 1928.



Ad from Literary Digest August 1928

[Synchro909]

I strongly suspect that those who have given themselves a fright at say, 50 mph are driving cars that need attention. I'd like to see that they have working shockers on them and that the steering etc is good. Mine felt quite stable at 60+mph. A brand new Model A was no doubt just as stable and as has been said, would run at that speed all day.

[AL in NY]

If your "A" can't run along safely at 55 MPH, you shouldn't be driving on public roads.

[rfitzpatrick]

TKS everyone -- my weak spot are the tires. I should have more tread on a 5 year old set
of Firestones I think

[mhsprecher]

What worries me most about driving these cars at higher speeds in the amount of tire patch on the road. Good tires and probably radials can help, but it's all physics. Friction is your friend. That goes for the brakes, too. Cast iron drums and well adjusted brakes are important, too. Off topic from the Burtz engine, however. I do plan to buy a Burtz engine for my Town Sedan.

[rfitzpatrick]

Off topic from the Burtz engine, however. I do plan to buy a Burtz engine for my Town Sedan.[/QUOTE]


Your reply is not 'off-topic'. I wanted to know my chassis weakness if using the Burtz. This is my last engine I'll ever buy.
TKS

[Jeff/Illinois]

Have you seen the new Restorer magazine, page 20, where that guy was about to pull into a parking lot and he herd a very loud BANG.

Pulled into the lot, got out to investigate, and the right spring perch broke the nut went who knows where the wishbone split and nothing was holding the front axle on the RH side.

Now, again, I reiterate.... wanna be running down the highway at 55 MPH plus and have THAT happen to you

Not me.............at 40 I thrive and come home alive!

[JayJay]

Originally Posted by Jeff/Illinois

Have you seen the new Restorer magazine, page 20, where that guy was about to pull into a parking lot and he herd a very loud BANG.

Pulled into the lot, got out to investigate, and the right spring perch broke the nut went who knows where the wishbone split and nothing was holding the front axle on the RH side.

Now, again, I reiterate.... wanna be running down the highway at 55 MPH plus and have THAT happen to you

Not me.............at 40 I thrive and come home alive!

I saw that article. Interesting, but it strikes me that this is one of those 1 in a million failures that are so far unlikely that I don't worry about them. Lots of other failures I would put in the same category.

JayJay

[GSleater]

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I've hit speeds of 75mph plus in my coupe with my Burtz block. Granted, I did add a stipe 340 cam a rocket 428 head and dual stromberg 81's. I still don't know what my top speed is and I'm glad I installed seat belts.

[rfitzpatrick]

[QUOTE=GSleater;2209335]I've hit speeds of 75mph plus in my coupe with my Burtz block.

You went 75? Plz tell me the condition of the rest of your Coupe. I have the '31 Budd Cab with an F-1 Steering, a 3:54 differential. Going with a stock Burtz too. I don't need speed, but I would like to keep up with local traffic.
TKS

[GSleater]

I basically rebuilt my car last year due to it being totalled. I am running 35 Ford wire rims and 16 inch tires but it gets bouncy at that speed. I did upgrade the brakes with a flathead Ted's kit but I've learned brake fade is no joke. My great uncle donated a 36 transmission. That being said I wanted to be able to keep up with traffic because of all the highways that I have to get on just to drive my car. On that note I prefer to take back roads and keep it at 55 and below.

[old31]

Interested to find out more about the 36 trans. Do you have photos? What did it take to get it installed. Is it a 4 speed?

[Kurt in NJ]

a 36 transmission has no provision for pedals or radius rod mounts, it’s a 3 speed with weak synchronizers, 39 and later got modern synchros.
they sell adapter kits to put in the V8 transmission

[GSleater]

I used a Clings adapter for my 36 box. I've heard that you can rebuild them with 39 ford components but honestly I don't know. My good model a transmission was destroyed in the accident and the one from the donor vehicle needed a complete rebuild. So far I do like my 36 box

[ModelA29]

Mine has a 39 trans with the Clings adapter. The wishbone also needs a bracket (included in the kit).
This site has a good breakdown on the 36-39 V8 trans. http://www.vanpeltsales.com/FH_web/f...sID_3speed.htm