Need More Power From The Chrysler 230 Flathead

[SasquatchSanta]

I just recently took one of my M37s out of winter mothballs. The 489 gears I installed last summer sure take a lot of starch out of the little 230 Chrysler Flathead. I've been planning on building a 265 Spitfire Flathead but with the price of fuel I'm having second thoughts.

I was wondering what a person could do to increase the performance and efficiency of the 230.

When we were kids the rage was milling the heads. With a compression of 6.7 to 1 one would think raising the compression (milling the heads) to say 9 to 1 would pay some handsome dividends n the power department. I've currently got my 230 timed at 15 degrees before TDC and it isn't pinging. That tells me (correct me if I'm wrong) that some higher compression is in order. Does anyone have an opinion of the benefits of milling the head and if so how high can/should I go.

I was also wondering about an electronic distributor and maybe even a different carb???

 

[Blood_of_Tyrants]

Only 6.7:1? Jeez, no wonder it's a dog. Yes, milling the head to raise the compression to about 9:1 will increase power by quite a bit. You might even go a little lower, say 8.5:1.

I don't know much about the engine, but if it has a tiny single barrle carb, it might benefit from a 2 barrel. MSD distributors will also raise power.

 

[rosco]

Fundamentally, you have the wrong kind of engine to hot rod. Its like four & 5/8" stroke. Thats what makes it great - for what it was built for - mostly "off road" with just a little highway capability. Its engine design came from the early '40's. You can tune it and make it more efficient. I recently had the engine bored to .040 & the machined surfaces cleaned up, like the top of the block, manifold surfaces (and manifolds), as well as the head. It got so I couldn't hold head gaskets. The block was out 0.009 & the head was out 0.017, so it was milled 0.026, plus a little. It is just used on the ranch, but I can't tell any difference in power. It about "broke in", now, and runs like a fine watch. Its all stock, except the distributer. I do have the vacuum advance hooked up, but sense there is no venturi vacuum port, it is probably of marginal consequence. Its balanced too, though.

Another thing is the carb & todays gasoline. When I get time to tinker with it more, I want to down-size the main jet. It runs too rich, regardless of the tune-up. Somebody has said, "it takes more air, to burn today's gas".

Lee in Alaska

 

[citizensoldier]

Here is one way

Here is one way you could help her out..

 

[SasquatchSanta]

RE: Here is one way

Blood of Tyrants wrote:

....it might benefit from a 2 barrel. MSD distributors will also raise power.

At one time I considered building a complete intake and exhaust manifold (header) system around a later model 2 barrel carb for a 265 flathead. That stopped me was lack of knowledge about exhaust manifold design.

rosco wrote:

Another thing is the carb & todays gasoline. When I get time to tinker with it more, I want to down-size the main jet. It runs too rich, regardless of the tune-up. Somebody has said, "it takes more air, to burn today's gas".

Excellent idea. This is something I need to do immediately. Thks for the insight.

citizen soldier wrote:

Here is one way you could help her out..

Hey Man --- I want one of those --- serve it up with a large beaker of nitro and a whisk broom and a bushel basket to sweep up and put the scattered parts in.

Seriously, what the he!! is that? What is it for? I want one!!!

 

[citizensoldier]

RE: Here is one way

It was on e-bay last week and is for a 230 flathead.. I was checking the funds and it sold for the buy it now price.. If nothing else it looks cool..

 

[citizensoldier]

RE: Here is one way

http://cgi.ebay.com/ebaymotors/ws/e...STRK:MEWA:IT&viewitem=&item=370057545062&rd=1

 

[Bill W]

RE: Here is one way

I know VPW's sold a performance/econo cam for the 230. As mentioned milling the head would help performance, there is also a electronic ign system out there that will fit in the mil dist or if its been converted to a civie dist you can convert that to a electronic setup from pertronix http://www.pertronix.com/ . If you don't already have it, heres a link to Egge engine parts http://www.egge.com/ they have good prices on 230 parts

 

[SasquatchSanta]

RE: Here is one way

At one time I thought I had a 265 engine located. After purchasing it, bringing it home and pulling the head I discovered it is a 251. Last week I did it again. I bought an old dump truck that was rumored to be powered by a 265. Because the block has a full flow oil system I was so sure it was a 265 that I didn't remove the head before pulling the engine. After pulling the engine I removed the head only to find I was once again the proud owner of another 251 Spitfire.

There really isn't a good way to tell if you've got a 251 or a 265 without pulling the head and measuring the stroke. The 265 has a 4-3/4 stroke where the 251 has a 4-1/2. I've had people swear that you can tell by the machined ID plane on the top front of the drivers side of the block . That ain't always so. Some blocks were used in both 251s and 265s. Also, these engines are so old that cranks were swapped around during previous rebuilds.

Oh Well --- The Quest Goes On.

 

[citizensoldier]

RE: Here is one way

So you want to sell some of them 251 parts? Palzy , Walzy?? Hmmmm... I have list of serial numbers that you should be able to check with the block to tell if it was a 251 or 265... Or do you have this list and have found the numbers to be wrong..

I sure could use one more good 251...

 

[citizensoldier]

RE: Here is one way

http://www.t137.com/registry/help/otherengines/otherengines.php

 

[SasquatchSanta]

RE: Here is one way

Citizensoldier wrote:

So you want to sell some of them 251 parts? Palzy , Walzy?? Hmmmm... I have list of serial numbers that you should be able to check with the block to tell if it was a 251 or 265... Or do you have this list and have found the numbers to be wrong..

I sure could use one more good 251...

Let me noodle on that a while. I just sold a truck and trailer load of M37 stuff. I kept two trucks, one has NOS everything AND 489 gears w/F&R lockers and another truck that is basically an excellent rolling chassis. I may sell all my M37 stuff and turn all my attentions to the M35s and my CJ2A. I'm in the process of making up a CD of that I may be selling. I'll include the engines on the CD as a seperate packag.

Thanks for the link. I think I also posted a list of 251 and 265 block numbers a few months earlier.

 

[randyscycle]

I am not particularly familiar with the Chrysler flatheads, but is the bottom end strong enough to hold up to any upper engine mods? I know much of the older stuff only had 3 or 4 main bearings and the connecting rods were a bit smallish.

I know that you wouldn't be turning huge RPM numbers, but still with more compression there would be more stresses on the bottom end, and how about the oiling system?

 

[SasquatchSanta]

I wouldn't want to push the 230 flathead any harder than milling the head a little. Having said that, I saw a truck at the Vintage Power Wagon Rally that had a 230 that was capable of turning 3600 RPM. The owner (Doug (Tex) Garrison) had built it on a bet and ran it to is home in Southern Indiana to Mt Pleasant Iowa against the governer which had been set at 3,600. It had been zero balanced with a cam and heavy valve springs, nitrited crank and other mods. From an outward appearance, outside of a harmonic balancer it looked like a stock M37 engine. It was geared with stock 538s with standare military tires.

The 251 engine has a stronger lower end and can be pushed a lot harder without breaking the bank to build the engine. Without balancing I wouldn't push any chrysler flathead, especially the 230 and 265 over 2500 RPM.

 

[BobM]

Buy a chrysler plane toter with the cummins engine/tranny and do a swap!

 

[Superdave]

I installed a 265 crank and rods into my 251 block when I rebuilt it and ballanced the rotating assembly. I installed the 489 gears with the 11:00 tires and the M37 will do 60 MPH easy all day long and I average 12 MPG on the highway.

 

[M37Dodge]

SuperDave

SuperDave - did you swap in a WC 1/2 rear end or splurge for the 9 5/8" 4.89 gears?

 

[SasquatchSanta]

RE: SuperDave

I've been told the civilian 230s had higher compression heads than the military versions. Supposedly, It had something to do with the military versions having lower compression so they could be compatible with low quality gas. Has anyone heard this before?

I've got a line on a head off a 1950 civilian (230) pickup. "Maybe" by installing the civilian head a person wouldn't have to mill the M37 head?

 

[amanco]

I don't know that this will answer your compression question, but there is a bit of info here with different years and HP ratings on civi cars & trucks with 218, 230, 251 and 265 CID engines And how about the 331 and 413 CID flat sixes?! I would love to see one of those monsters!

http://www.allpar.com/mopar/flat.html