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Hotrod a '52 Chrysler flathead 6 ???

43180 Views 29 Replies 11 Participants Last post by  pk44
Hello.

I have a 1953 Chrysler crown flat head six. 1t's a mere 125hp at about 250ci (but very impressive torque). I am looking for some insight as to the theroy and practice of buiding such an engine up (just 20-30% or so). Given what you'all can do with an ancient ford flathead, there must be something.

The vintage Chrysler engine guru's and machine shops I've talked to say I'm nuts trying to squeeze a few more horsepower out of it. I find that hard to believe because Chrysler added 10 h.p. in '53 just by stroking it (a crank and rods are really hard to find).

I was first going to put a '37 Graham Super charger on it. That really spun some eyeballs in there sockets. I was told I'd be blowing head-gaskets left and rt or blasting the head right of.(begs the question what did Graham did to their flathead sixes in 1935 to avoid this sort of catastrophe.)


My last, meager thought was to do something with the cam. The machine shop said they wouldn't know where to get profiles and I'd be playing with fire because it's old iron (heh).

I can't believe you blow an ancient flat head ford and milk all sorts of hp out of it but I can't squeeze some out of this 1000lb behemoth.

Anyway, anyone have any ideas or insight as to what I'm really up against and what an how can I do with this thing?

Regards, PK
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Well I think most places have never worked on one of those monsters so they really have no idea on what to do. Can you get rebuild parts from Egge or Canter?? Your wrong in equating your engine to a Ford flat motor, there always was quite a bit of high perf. parts made for it and still is.

Now, if you can get new pistons, rings, bearings, gaskets and such. Get the cyls. bored properly to seal it up then you might be able to mill the head a "little" to increase your compression. You will need to find a company that would be willing to give your cam a regrind with again, a little more duration or whatever they deemed would work for you.....and good luck with that.

The problem is that even if you could do all of the above you're still stuck with an ancient 1 bbl. carb (I think) and an engine that was never intended to be anything more than what it is right now. Years ago I know a lot of the old boats like Chris Craft were equipped with "Gray Marine" engines and I'm pretty sure some were Chrysler 6 bangers. You might google that info to see what comes up.

If you need a good machinist go see Jim Larr at "Orange Engine" in Anaheim, (714) 635-4030....1911 E. Ball Rd. just west of State College Blvd. This guy really knows his stuff, builds race through stock and quite a few odd balls. He might have a few suggestions.......good luck ....but don't get your hopes up.
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man.... your in orange county cal....he** yes you can do just about anything......a lot of antique custom rod shops out there....all it takes is time and money... sounds like you are gonna have bolth...check with some local nostalgic car clubs out there..i lived there for over 40+ years,,, a lot in your area......
Thanks alot for you feedback Guys, Just what did (not) want to hear.

327 nut: I want get back to you with more info because ...(don't no if I should say this around here) this is indeed out of a Chris craft and it is to replace a 1935 95 hp Chrys. Crown.

Gotta run but I' be back to pester with more. Thanks alot.

Regards, PK
those old flathead 6's can be made to run.. headders and a dual carb manifold is available for it.... www.stoveboltengineco.com sells both, or used to.. I'v seen some Mopar flatheads with blowers on them. compression is likely under 8:1, so it's not like it's going to raise the compression to some astronomical leval
Ah yes the flathead hotrod....the one thing I know about flatheads is that they don't like high RPM running....if machining....focus on high torque low rpm configurations and gear accordingly......

This lesson was learned from an old schooler who has since passed on...

I get a little excited every time I see a hot rodded flat head...there is an originality to it that is just the ****...
If not machining....I would just go the simple vintage aftermarket intake if one can be had for this engine...updated ignition system...maybe retrofit a multi-spark type system with a crank trigger (may take a little fab work)....and find a header for it or have one fabbed...have a custom exahust made for it....maybe lake pipes....you know with the block off's coming out the side....and loose the hood...
JackHandy said:
If not machining.......maybe retrofit a multi-spark type system with a crank trigger (may take a little fab work)....and find a header for it or have one fabbed...have a custom exahust made for it....maybe lake pipes....you know with the block off's coming out the side....and loose the hood...
Jack thanks for the reply. just for the record. it was born with twin carbs.

I'm interested in go for broke machining and fabricating approach(if I can get my old CNC running). Just need guidance as to what exactly I'm cutting and grinding and how much.

Actually, I'd like to learn how to figure it out for my self (with some tutelage I know).

I didn't want to get kicked off of here so I kept it low key but this motor is from Chryslers marine division . It's going into my '35 speed boat. They also made versions used in trucks and industrial applications.

As to the torque, take a look at the stock curve I am going to post below. Never seen anything like it.

Regards, Pk
we talk about marine engines/ boats on here from time to time.. your not going to get kicked off the forum or shut down for asking about them
matt167 said:
those old flathead 6's can be made to run.. headders and a dual carb manifold is available for it.... www.stoveboltengineco.com sells both, or used to.. I'v seen some Mopar flatheads with blowers on them. compression is likely under 8:1, so it's not like it's going to raise the compression to some astronomical leval
Thanks for the link. I'll definitely check it out. Ya the compression is a wopping 7 or 8:1. I just don't get the people who tell me I'll blow the head off. I can pully the blower down, just don't know how much.

Regards, PK
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327NUT,

Thanks again for your input. hope you can struggle through this novel.

1) All stock parts are available. Pistons are a $125 per. The last time I checked for my car, I could spec on-line custom pistons any which way for about the same price (but, 3yrs ago or so),

2) Cylinders, what to you is a proper bore? It has to be bored about .oo3 over. Is “proper” just boring it respectably vs. not at all? Are there established shops that are still incompetent?

3) The compression would seem like it has a ways to go, it‘s 7 or 8;1. But the problem I’m told seems to be the flow through the head so higher compression might aggravate that situation. I suppose conceptually bigger valves might help alleviate flow issue but they’re close together, close to the cylinder and, the block cracks between the valves cylinder to valve anyway. Not sure why, overheating…

I’d be interested know how flow issues are handled in other flat heads (fords ?).

5) Normally one carb would be an excellent bet for these motors. Mines an “S”(special) so it’s got 2 carbs. Given the second carb, can much more be accomplished in carburetion alone? (I could fuel inject it or even put my old blower (lets just say it’s in my repertoire)

The stock carbs by the way are funky up-draft(?) u-shaped things, zenith I think. I want everything to be period correct. (for fuel injection, I could gut the carbs and stab injectors in som discreet place.

6) Goolging the motor inevitably gets you to real nice sites if you’re a retired CEO wondering exactly where to have your “boy: mount your new $800 NOS bow light or on the other end of the spectrum, how to get the bubbles out of you hand poured babbits on a turn of the century, 1 cylinder 4-8 stroke.

7) I definitely will call Jim Lar. I really just want some with the knowledge, creativity, and a little educated ***-ness. If I can’t do much so be it but man, 20 hp per hole on a 250ci motor…

Thanks much for your thoughts. Regards, PK


FOR THE RECORD


By kroak at 2009-06-12
From Chrysler


By kroak,

All 1200lbs. Striped to the last nut, gotta be a lion in there lookin' to roar...
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pk44 said:
Jack thanks for the reply. just for the record. it was born with twin carbs.

I'm interested in go for broke machining and fabricating approach(if I can get my old CNC running). Just need guidance as to what exactly I'm cutting and grinding and how much.

Actually, I'd like to learn how to figure it out for my self (with some tutelage I know).

I didn't want to get kicked off of here so I kept it low key but this motor is from Chryslers marine division . It's going into my '35 speed boat. They also made versions used in trucks and industrial applications.

As to the torque, take a look at the stock curve I am going to post below. Never seen anything like it.

Regards, Pk
That makes a lot of sense, the Chrysler flat head 6 saw a lot of industrial and marine applications in its day. Lycoming or Continental also built them under license just to add to the Chrysler flat head 6 industrial and marine engine plethora of the period.

Compression is always pretty low on flat heads, making them ideal for a supercharging, a 1930's classic Winfield or McCulloch would look so good on this engine in your 1935 boat.

Bogie
2
Check out this article about Earl Edgerton who runs the Mopar flathead 6 at Bonneville and has gone 135+. www.moparmagazine.com/2008/sept-oct/edgy_mopars

He produces finned aluminum heads (aobut $750) for both the long and short block Mopars. Also has a cam grinding machine and will regrind your cam. His push truck at Bonneville was running an overhead valve setup that Earl designed and did a one off of. He is a wealth of knowledge.

His shop is located in Santa Rosa, CA www.edgyspeedshop.com/

While mine is the short block 218, I have bored it 0.060, added dual Carter/Webbers on an Offenhauser intake, cast iron headers, and a modified HEI distributor from a V6 Chevy S-10. Runs great and with the OD transmission from a 53 Plymouth my 48 Plymouth Coupe runs with freeway traffic all day. Won't win many drag races, but it does draw a lot of attention in the sea of V8's.



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August 09 Street Rodder Magazine page 122.

1949 Plymouth flatty 6 - 217 opened up to 230.

Parts from Edgy (as listed by hkestes), Langdons (as listed by Matt 167), plus others.

Featured in a magazine. What else can you say?
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Pretty pictures

Thanks all for your input and letting me into your lair...with an old boat. I want to digest and address all your comments but duty calls this weekend. Suffice to say, with all your input I've been able to put together a clear path an plan to accomplish pretty much every thing I wanted.

2 days after joining this forum, after 9 months of fruitless dealings with the established network of entrenched. "professional" boat restorers... I'm where I want to be.

Anyway, until I get back, thought I'd complete the picture of where I'm heading (And probably get booted off this forum for it(grin)).


By kroak, shot with W580i at 2009-06-13
My '35 19ft Chris Craft. Before and during, seems like about a linear mile of new planking, a couple gallons of varnish and more to go. Then it's ready to be flipped to do the bottom.


By kroak at 2009-06-13
A finished 1937 (not mine). The motors a re-badged Hercules industrial flathead 6 between 218ci-250ci with 1 to 3 carbs. HP stock from 95 to about 135

Look close at the original dash and you'll see the, optional 17" banjo steering wheel ( I want an old sprint car wheel), a clum switch, throttle lever in the middle of the steering wheel and the original SW dash-panel with oversized, domed glass SW gauges. It's also got a faux(?) machine turned face and a CCW tach. (Funny thing is the gauge panel is shared with the '37+ Willy's coupe).

BTW: Who knows the thought behind the interior color.

Back in a day or 2 & thanks again all, PK
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PK....yes do call Jim if you need some machine work done, maybe he can help you on the price of the parts also......and believe me all shops ARE NOT the same!!

Also, I don't know squat about these engines so I'm going to hand you over to "HKestes". Looks like he's had hands on experience and can be a lot more help than me.....and a beautiful looking flatty to boot. Good luck with your project, I can see you cruising across the crystal clear waters of Lake Tahoe already.....
So, this kinda cool,

I called Jim at orange Engine at 327NUT's suggestion.

Had a real can do, no biggy attitude about what I wanted to do. He even new some history of Chrysler flathead 6s'. The cams going to be ground so it will run fine on my carburetors (until I fab a manifold for the blower, where it will shine). Head and block are going to be resurfaced somehow so they fit really well & so presumably the blower is not going cause problems up top.

.030 overbore, crank is fine, found a place that actualh has pistons and bearings and another that actualy has the complete marine gasket set.

Glad I found this place. Knew it could be done but spun my wheels forever going through traditional channels.

Thanks all for your input, keep you posted as things progress.

Regards, PK
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thats awsome, the boat looks super cool, i have always loved those old chris craft boats, never knew what motors they had in them, you learn something new every day, good luck with the project, i think hotrodders can be boat people as well :thumbup:
Kinda OT, but here's an ARTICLE on a Bonneville-bound Dodge flattie four. Lotta enginuity went into this deal.
cobalt327 said:
Kinda OT, but here's an ARTICLE on a Bonneville-bound Dodge flattie four. Lotta enginuity went into this deal.
Pete who owns this roadster is good friends with Earl Edgerton who I posted about up the thread a ways. Earl has done a lot of development on the Mopar flatheads.
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