More Power?

[Eric47Dodge]

I bought a '48 230 from a guy for $100. Am planning a rebuild and hop-up to eventually put it into my '47 D24 that we run at Bonneville. Current motor is running fine, but is putting out every bit of power it is capable of without internal mods. I have access to a pal with a machine shop. I'm thinking of 1) more CI; 2) more compression; 3) better breathing -- density altitude at Bonneville is usually about 6500 feet. I have an Offy intake with 2 Holly 94 carbs now, and headers that I got from Tom Langdon, along with one of his high-energy ignition conversions. This motor doesn't have to be street-reliable, as it will only start, run for 3 miles, and be shut down. Right now, I run without a fan and generator. The car is powered by a 1700 amp 12-volt battery in the trunk.

Question for all of you hot-stove car guys -- what can/should I do to my spare motor to generate more horsepower using the accessories I already have? Only restriction on the motor in my class is that it can't be supercharged, and it can't run on nitrous (or fuel -- has to use gasoline as fuel). All suggestions welcome. This may be a two-winter project, as SCTA made some safety rule changes effective Jan 1 which will take some re-working of our roll cage and other items. I need to get those accomplished first in order to be able to run next summer. Thanks, Eric

[Guest G Wellman]

Check my post about the 251 engine with dual carbs and dual exhaust. There is a website that lists much more info and pictures of this engine.

These engines are better than the 230...no offset rods, shorter stroke etc. My is an industrial version which were even more sturdy. These engines are about 2 inches longer than the 230s and many people have installed them in P-15s and other cars and trucks....some modifications necessary.

GWellman@mac.com

[Don Coatney]

Eric;

In talking with George Asche a few weeks ago he told me about a radical cam shaft that he has. It was originally used in a modified circle race car. It has a bunch of duration, lift, and overlap. It will not idle below 2500 RPM's. This cam along with oversize pistons and a severly milled head should increase your horsepower a lot. Give George a call. His number is in the links section of the main page supporting this forum.

[grey beard]

Yours is an interesting question. I know that we all have about the same basic local wisdom on these things - like Don just mentioned above, but I have always wondered how high one could jack the compression ration on these flatties without running into other major engine problems.

I took 100 thou off of my own 218 cylinder head and still had lots of clearance left above the valves when they are open. I've no idea what the compression ratio is now, but I'm guessing around 8 or 9:1. Years ago, in the sixties, production high performance engines were built with compression ratios approaching 11:1. Wouldn't it be fun to see how a flattie would respond to that treatment! We understand that octane and advance curves would need to be minded pretty carefully, but compression ratio is the seconed "never-fail" performance recipe, right behind cubic inches.

What I'm suggesting probably could not be achieved by simple head milling - might take some head reworking to keep valve clearances safe, especilly with that cam stick Don is suggesting, but I sure would like to be a fly on the wall when an 11:1 ratio flathead was tried out. Wish I owned one. JMHO LOL

[Don Coatney]

Now if you really want to go wild here is a picture of a releived block. This would require a big blower as improved flow would be the only benefit. Compresion ratio would be low as the size of the compression chamber is larger due to the material that has been removed.

[Don Coatney]

I took 100 thou off of my own 218 cylinder head and still had lots of clearance left above the valves when they are open. I've no idea what the compression ratio is now, but I'm guessing around 8 or 9:1.

Dave;

How many pounds of pressure do you get on a compression check? The number will somewhat indicate the compression ratio.

[greg g]

When I had my 230 done, I took .010 off the deck, so don't leave that out of the equation. The biggest difference between the 218 and 230 is the clearence between the piston and the top of the block at TDC. My 230 ended up almost dead flush, a straight edge showed about .005, where as there was > .040 on the 218. I would think that the two weakspots with a really tight compression ratio would be the headgasket (is there room for "O" rings between) between the siamesed cylinders, and the extra pressure on the rod bearings. I sent Eric a wax casting of the sompression chamber from my edmunds head (Don't know if it was as produced but supposidly had a 9 to 1 CR) So maybe he can determin a chamber design from it. It seems counter intuitive to remove material to increase Cr, then have to relieve some around the valves to regain air/fuel flow. I think you could also achieve some gains by matching manifold and block port shapes, and opening/smoothing the path of the inlet and exhaust. I also sent Eric a note regarding his exhaust design. In the pictures he has posted, I note that he has it exiting right out the side under the front fender. I wonder if the flathead would benifit from some scavenging effect that a longer exit might provide. Another consideration might be to design and intake manifold to utilize side draft carbs, to get a flow with less change of direction. Something like Jaguar used on their dual and triple carbed 3.7 and 4 litre X series engines. Even those SU/Solex might be utilized, they are simple, have external jet adjustment and once set up and tuned fairly reliable. They also work at pretty low fuel line pressure like the Carters. Couple Webbers though much more expensive than the SU/Solex would work to but they are much more complicated.

With all this better oiling of the rotating bits will probably be needed, Do the rules allow for Dry Sump oiling.

[Eric47Dodge]

I think Greg's combustion chamber ideas make sense and will be exploring those with my machinist pal. Has anyone had any success in enlarging the displacement of the 230? Can't use Don's block-relief scheme if it would require a blower, as supercharging isn't allowed in our class. Also, I talked with Charlie Price, the guy who runs Vintage Speed a couple of years ago at Bonneville. He said that he was going to be offering aluminum high-compression heads for the Dodge flatheads, but I don't see anything on his web site about them. Has anyone heard something about that? Thanks, Eric

[Christopher]

Eric,,, I got a guy over here, ]wenatchee] that builds race engines for the roundy round guys,He learned his trade , in the early 60s from guys that raced mopar flat heads..right now he is biulding a 318 for me. We have discussed a hot flatty, I believe he may be of some help with some good advice..I work at home so Im around most of the time..Mr@americancane.com or better yet give me a call..509 745 8344 Christopher ..from the high and snowy lonesome..

[greg g]

Careful, Eric is from the darkside. Your high and lonesome magic might not work correctly.

[Christopher]

He will need to re jet. and check for rust daily....Christopher. from the brightside of the state....

[Guest rockabillybassman]

Interesting.

A guy called Bugman over at the Hamb is developing alloy heads.

It seems to me, from reading gazillions of pages at inliners mopar forum by Hud and Hudsonator, that the recipe for success at Bonneville would be in the ability to run at 5-6000 rpms. Getting sufficient fuel into the chamber does'nt seem to be a problem with these motors, but surviving at those rpms does. All the usual bottom end tricks would be needed, cross-drilled crank, reworked bearing shells, high oil volume, possibly custom built main caps or a girdle, maybe boxed rods etc, etc. Hudsonator's 230 runs between 5 and 6000 and survives. I think a custom built oil pan or even a dry sump setup would be the go. Some long legs in the rear axle, or a 5 speed would be a necessary too.

[greg g]

Hmmm, bugman also has one of the wax castings I made of the old edmunds head, coincidence????? Nah just trying to help a couple fellowsout.

[bob westphal]

Eric needs to think about the fact that his needs are different than circle track needs. He is going for top speed. Rockabilly is definately correct about the bottom end. These engines were infamous for lower end problems. Many years ago I ran a built 218 on the strip. 10.5 head, dual 94's, Isky 3/4 cam, ported, light fly/clutch, homemade tube headers, and hardened crank. I had no problems in the 1/4 mile runs but my brother smoked the crank in a top end run. You will need a cam designed for top end. The exhaust tuning is a must. Your engine should be airflowed and balanced too. Also lightening the rotating parts. I suggest that you do a little research into people that are building top end engines. Talk to them and follow their basic procedures. Don't confine yourself to people that build old engines. Engines are basically the same in function. What works on one should work on another. Different types of oil is also essential. I used to use lighter synthetic oils and ran less oil on short runs such as timing in. These tactics really work!!!

[Don Coatney]

Hudsonator's 230 runs between 5 and 6000 and survives. .

rockabillybassman;

I have had long discussions with both Mark Hudson and his dad about there high RPM 230 engine. It is in a "CUSTOM" pulling tractor. Yes it does turn in excess of 5000 RPM's but it only does this for a few seconds at a time. They have made several runs down the pulling track with no failures and have not torn there engine down for quite a while. A 3-4 mile run down the salt would be a whole different animal.

[Eric47Dodge]

I have made a number of 3-mile runs with my current motor at 4000 to

4200. Tach is bouncing a little, so it is hard to be exact. Motor has been solid. If I could get another 500 rpm in high gear, I'm sure it would push me past my personal goal of 100 mph. Car is a little squirrelly at top speed on the salt, so I am not too worried about getting to 6000 rpm. A 4700 red line would be fine. Need to have the power to pull that in high gear though.

[Guest rockabillybassman]

I hear what you're saying Don, but I see no reason that Mark's motor would'nt survive. They've done a lot of work on that bottom end.

[fredsv8shop]

Running the old girl on Santa Pod in the UK during hollydays just for fun,

Meaning no prep at all, all the camping gear and beer still in the boot, fully

loaded that is because Marianne packed the car for a 2 months trip while

we where only going for 2 weeks. We run a 265 Ci , unleaded fuel and a

non vacuum advance industrial ignition, a 3.57 rear end and 25+ year old

tyres. And keeping in mind that we had to return to The Netherlands in

one piece with the car had a restriction on my right foot !!

The scary part wasn't driving fast over the track but decelerating after

the 1/4 mile mark that was scary, I had the feeling that the car would do

all but keeping a straight line I had to keep the throttle on and decelerate

slowly and therefore needed the whole top fuel lenght of the track.

But let me tell you it was a experience of a lifetime !!

And yes I feel that without all the slowing down stuff in the car I can

improve the numbers on the scoreboard bigtime.

I will try this someday.

Fred

[Normspeed]

Great picture Fred.

[Guest rockabillybassman]

Excellent! Back in the 70s I ran a T bucket with 351 Ford V8 to 13.1 secs @ 105mph. Scared the s**t outa me when the front wheels came 4" off the deck! I'm content to go a lot slower these days Awesome to see a flattie six on the strip.

[fredsv8shop]

Flat six hooking hard

Fred

[David Muma]

Have a look at the inliners site... under the mopar section...

http://www.inliners.org/cgi-bin/ultimatebb.cgi?ubb=forum;f=8

there was a great discussion of mods to flatheads.... some say they were turning as high as 8000 rpm... many tips to improve longevity at high rpm...imcluding drilling the crank for better lubrication