soup upa 251cui chrysler flathead

hi,

I was wondering if it's possible to soup up the engine a little?
The car has fluid drive transmission. Can i make ot faster some how?

Danny

 

More compression will help that old slug. Mill the cylinder head .060 or so. Also, split the exhaust manifold and run dual gl***packs.....you may not be going faster, but it will sound like you are.

 

When I was a kid, the old stock car dirt track in Rhinebeck at the Fair Grounds banned Ford flathead V8s and lots of guys went to the Mopar flat sixes. From what I remember as a teenager they went pretty good.

 

There is a lot that can be done with these engines. They are very detuned from the factory so a few old time hop up tricks go a long way.

First the engine has to be in good shape. A slightly worn engine, that may run for years if you baby it, will blow sky high in a month if you hop it up.

Start by doing a compression test. Ideally you should have 120 PSI in all cylinders, or close to it. Also your oil pressure should be good, 40PSI at 30 MPH and 10 or 15 at idle.

These engines are foolers. They will continue to run smoothly with no knocks or bangs in an advanced state of wear.

So if your engine has under 50000 miles or has recently been rebuilt, here we go.

As previously mentioned the head can be planed up to .080 for more compression.

The manifold can be split for dual exhaust. The easiest way is to make a 4 bolt flange that bolts on under the center of the manifold, using the original bolts that join the intake to the exhaust. Weld your new exhaust flange on there. Headers are even better but have to be custom made. Although, there are cast iron headers available.

There is an adapter to put a Weber progressive 2 barrel on your manifold. I think Patrick's chevy parts has them. They have a few other goodies too like dual exhaust manifolds.

Or go old school and weld 2 flanges on your original intake for 2 or 3 carbs. For twin carbs you block off the middle flange with a plate.

Edgy Edgerton is the expert on these engines, he will regrind your cam for $165. He can also regrind your lifters, new or reconditioned lifters are necessary with a new cam. Install new valve springs, shimmed .060. While you are at it a 3 angle valve job or mild porting will help.

He also has finned aluminum cylinder heads but they cost $685.

The distributor can be recurved in the usual way.

Last but not least a special speed secret for Fluid Drive owners only. You can drain off a couple of quarts of fluid from the Fluid Drive unit for whippier acceleration. This has the same effect as a high stall speed torque converter.

 

Truck engines had a dual carb, dual exhaust setup for those engines, I have two of them.

 

Maybe a dual carb system is possible for me if a '49 manifld bolts on to a '51 engine. This way i can try to make such a setup withiut destroying the original. Parts aren't easy to find her in the Netherlands. I do have a spare carb and manifold. But what's with the fluid drive wiring on those carbs?

 

I put a 251 in a 41 Plymouth coupe I had in the early seventies, milled the head .080 because an experienced local machinest freind of my Dad did it for free for me. That car went really good and I later put one in a 50 Dodge with similar results. They were strong without huge changes so I would guess they would respond well to hopping up.