Jump to content


Photo
- - - - -

Higher Performance 230 Rebuild


  • Please log in to reply
63 replies to this topic

#1 maineSSS

maineSSS

    Member, been hanging around a while...

  • Members
  • PipPipPip
  • 31 posts

Posted 15 June 2012 - 10:13 AM

Hi all- I've owned a '49 Power Wagon for a number of years that I've been working on, and am getting squared away for an engine rebuild & upgrade.

I've used both the Ball & Ball and Fish M-2 carburetors, and will be trying out a triple CVK 40 (Harley carb) setup on the rebuilt engine. I also will be using a '59 head for the 230.

I made up some clear head chambers from casting resin so I could observe flow when I do flow testing on a junk block. I'm going to be looking at valve shape and seat angles very closely, as that doesn't seem to have been done before. I have a friend who is a professional head porter, and will be asking him what I can do with port shape to improve breathing- the flathead's big weak point. I'll be looking at keeping velocity up, as this is a street-oriented build.

I'm wondering if anyone has done CV (constant velocity) carbs on a 230 before- the Harley carb is CV, and has been used quite successfully on Samurai's, as it will run upside-down. I heard that the Ramcharger group campaigned a sidedraft 230 back in the 60's, anyone have any info on it? (I suspect it probably used SU's).

Another thing I'm thinking of is a lighter piston- is there a modern piston that will substitute for the stock 4-ring monster? Less weight would certainly help 60 yr old parts at higher rpm...

#2 greg g

greg g

    Zen Master, I breathe vintage mopar!

  • Members
  • 15,036 posts
  • Locationmanlius, ny

Posted 15 June 2012 - 12:30 PM

with the nearly 5 inch stroke of the 230, piston weight is not nearly the concern as piston travel, and it's associated friction loses, trying to build for mouch over 3800 Rpm is self defeating.

I believe a couple of SU's off a similar sized engine like a Healy 3000, or 4 L Jag, would be a nice set up and easy to accomplish, plus they have adjustable jets so tuning for mixture is pretty easy also.

matching the ports to the gaskets is doable upping compression will get you some good snap also.

You have the right to freedom of choice. But, you are not free from the consequences of those choices.


#3 Rusty O'Toole

Rusty O'Toole

    Guru, have been a long time contributor

  • Members
  • 813 posts

Posted 15 June 2012 - 12:43 PM

There is another thread on hopping up the flathead that has a picture and description of a newly made custom piston.

The poster used rods from a shorter stroke motor, which are longer. This put the pin higher and gave better rod angularity. The pistons are 100 grams lighter than stock and considerably shorter, more like a modern piston.

The old rules on piston speed and acceleration don't hold as much water as they used to. Today's pistons and rings will stand more stress than the old type and then there is synthetic oil.

In your case you might use 217 rods with custom pistons and get a performance and longevity boost even if you never revved it higher than a stocker.

There is also the possibility of putting a 250 or 265 six into your Power Wagon, they were standard equipment in Korean War era military Power Wagons.

#4 Rusty O'Toole

Rusty O'Toole

    Guru, have been a long time contributor

  • Members
  • 813 posts

Posted 15 June 2012 - 01:09 PM

Re: the long stroke of the 230. It is considered a long stroke engine because the stroke is greater than the bore but how does it compare to some modern, short stroke motors?

Dodge 230 = 4 5/8

Chev 454 = 4

Cadillac 500 = 4.304

Pontiac 455 = 4 7/32

Olds 455 = 4 1/4

Slant 6 225 = 4 1/8

So the stroke is long but not crazy long compared to some well thought of, more modern motors.

With modern light weight pistons and a careful balance job 4500 or 5000 RPM should be within reach. Maybe not the kind of motor you want for a Power Wagon but not out of the question.

Edited by Rusty O'Toole, 15 June 2012 - 01:12 PM.


#5 moose

moose

    Guru, have been a long time contributor

  • Members
  • 651 posts

Posted 15 June 2012 - 01:55 PM

Comparing apples to oranges. Comparing a Mopar 230 to a Chevy 454.

If the 230 had the same bore to stroke ratio as the 454, the bore would be 4.91, and the total displacement would be 526 ci. If only that could be done huh? The block would be about 3-1/2 feet long!

Maybe its more like apples to pineapples:)
Moose

www.manifoldsbymoose.com

"Overhead valves are just a passing fad"

#6 Rusty O'Toole

Rusty O'Toole

    Guru, have been a long time contributor

  • Members
  • 813 posts

Posted 16 June 2012 - 04:33 AM

Exactly. Comparing "short stroke" to "long stroke" motors is comparing apples to oranges. Can you tell the difference?

Some so called short stroke engines of large displacement actually have quite a long stroke.

The longest "short stroke" on the list is the Cadillac at 4.304. No one would be shocked at a hopped up Caddy revving 5000 RPM. The Dodge at 4.625 should be able to do the same, if it had light weight pistons, modern rings and a good balance job.

Whether this is advisable or not, especially in a workhorse like a Power Wagon, I can't say.

The point is, if you want to invest in more modern, light weight, pistons the potential for higher revs is there.

#7 40P10touring sedan

40P10touring sedan

    Guru, have been a long time contributor

  • Members
  • 673 posts

Posted 16 June 2012 - 05:18 AM

Cross drilling the rod jounals would help in the oiling for safe higher revs...hudsonator{?} did this to his 23" and improved the oil pressure via milling of the pump top and could hit 5000rpm all day and touch 6000rpm in short bursts on a tractor. I, myself, wouldn't need to hit 6000rpm but the possible hitting of 5000rpm and having longivity of your crank does sound nice...heck, a solid 4500rpm would be great at any point. The limiting factor with these 6's is the low revs and the prone crank failure if one takes the revs higher without modding the oiling system.
The one thing I saw with that build that I don't exactly agree with is the addition of a groove on the rod and crank bearings for added oil flow{I could be thinking of another build too, been researching afew of these lately}...I feel this would take away from the bearing surface area which to me would be a no-no.
Talk was the possible use of slant 6 offset pistons but no one could figure out the mild offset those pistons have so that's in limbo at the moment.
Bob- proud owner of a 40 plymouth touring sedan and a 54 kaiser McColluch supercharger - now how to get them together!

#8 40P10touring sedan

40P10touring sedan

    Guru, have been a long time contributor

  • Members
  • 673 posts

Posted 16 June 2012 - 05:40 AM

One thing I've noticed with these builds is the use of flathead pistons since theres no o/h valves and to mill the head upwards of .060 to .080 to raise the compression...but this can hurt the air flow while doing it by lowering the pocket over the valve area. I wonder if a slightly domed piston could do the same effect while leaving a nice open pocket over the valves for good flow...the valves are raised over this block so relieving isn't needed like with the ford version because of they're low valve pockets.
I want to use the shorter skirted type of pistons to aid in even less weight and sidewall friction as opposed to the keithblack type of aluminum long slugs that are out there.

I have a McColluch supercharger and would love to use that on my 265 but I've got no support from them{paxton} so far as to how to repulley mine to be used for low rpms and still get full boost..a turbo set up would be the same problem..need higher flow to get higher turbine revs to get full boost. Naturally aspirated is an easier way to go, but one of these days someone has to break this barrier for the good of all!
Bob- proud owner of a 40 plymouth touring sedan and a 54 kaiser McColluch supercharger - now how to get them together!

#9 40P10touring sedan

40P10touring sedan

    Guru, have been a long time contributor

  • Members
  • 673 posts

Posted 16 June 2012 - 05:48 AM

...There is also the possibility of putting a 250 or 265 six into your Power Wagon, they were standard equipment in Korean War era military Power Wagons.


With these 25" motors, they have the larger rod journals at 2.125" as I recall...one could offset grind that back to the 23" block's 2" size and have a slight added throw...is it worth it for the small amount of added cubes...that's going to be your call whether it's a "get everything I can build" or "well, that's not worth the machining but I'll do everything else"....as I recall those rod bolts{23" too?} have T bolts for the rod caps to keep the width down so to attempt to increase the crank throw would require checking the block clearance and getting some good new rod bolts{ARP?}.
Bob- proud owner of a 40 plymouth touring sedan and a 54 kaiser McColluch supercharger - now how to get them together!

#10 Don Coatney

Don Coatney

    1948 P-15

  • Members
  • 19,036 posts
  • LocationNorthern Indiana
  • My Project Cars:1948 P-15

Posted 16 June 2012 - 08:52 AM

Would be interesting to do a flow test on the engine pictured below. I was told this engine was used in a circle track racer back in the day. Seems to me that the relieved section would cut the compression ratio down a lot and compression ratio is what makes horsepower in these engines.

Posted Image

Don Coatney

http://smg.photobuck...519373465134713

 

 

An opinion without 3.14 is an onion.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 





0 user(s) are reading this topic

0 members, 0 guests, 0 anonymous users