218 Vs 230 Cubic Inch Motor

[Dodgebawl]

I have a 49 B1B that I am doing a frame off restoration on and I am getting to the point where I will have the engine rebuilt.  The engine is a 218 with a 4-speed tranny and stock differential.   Other than disc front brakes and conversion to 12V the truck is stock.  I am wondering if I should convert the engine to a 230.  For those of you who have made this conversion is there any appreciable improvement in performance which would justify the cost of crank, rods and flywheel to convert to a 230?  If I stay with th 218 I will have the head and block shaved (how much I have not decided) for more compression and have the cam reground for mild performance improvement.  And, if I do convert to a 230 will I neet a carb. other than my stock one bbl?  Your thoughts and input is appreciated. 

[drillmastertommy]

I started a similar thread to this in another section of the forum recently,

http://mopar.pairserver.com/p15d24ph_forum/index.php?/topic/32356-218-to-230-flathead-how-much-real-difference/

From the info I've found it seems to me if your keeping the engine stock(ish) then the 230 is gonna make a significant difference over a 218. I would imagine finding 230 cranks and rods will be considerably easier in the trucks homeland than over here in the UK.

[John-T-53]

I ended up converting to a 230 because the old 218 crank was found to be cracked. I found a good 230 core and only had to grind it .010 and .010, which should last a long time and more rebuilds down the road.

 

I'm glad I did. With the cylinders bored .060 over, it's a 238.I can't provided a base line comparison because dual carbs were also added. But with all the changes, there's considerably more power and low-end torque. I don't have to downshift that much on hills anymore, in fact I can climb moderate grades in overdrive (2.95:1 final ratio).

 

The flywheel is the same between 218/230 cranks. 230s just have 8 holes instead of 4. (Side note: 1941 218 cranks have 8 holes too).

No need to change the carb.

[Scruffy49]

Hmmm... how hopped up do you want it to get?

 

These are supposedly "the" tricks on the small blocks (23" engines): Increase main bearing oiling grooves, 3x as wide, 2x as deep. Plug oil squirter holes in rods if mains are modified. New rotor type oil pump, with 1/4" spacer behind the relief valve spring. 1955 or newer crankshaft. Polished combustion chamber. Head milled .060-.125 or swap to a later head or aluminum head.Block intake and exhaust ports cleaned up, port/gasket matched, smooth polish the exhaust ports, leave intake ports kind of rough for fuel atomization. 1957-59 Dodge car 2 bbl intake and carb or run a dual 1bbl intake. Split exhaust manifold or some form of headers. 1957-59 cam specs or have yours performane reground. 1951 or newer distributor with removable plug so you can adjust the vacuum advance. Increase all engine clearances if you hop it up...piston skirt .004, bearings .0015-.002, valve tappets at .002 over factory specs.

 

NOTE: I have done none of the above yet, info swiped from Don Bunn and Tom Brownell Dodge Pickups History and Restoration Guide 1918-1971, 1991 edition.

[Dodgebawl]

Scruffy49,  As far as doing performance enhancements I plan to limit them to what I mentioned in my post.  My question is, assuming everything is equal, is there a significant performance gain by simply converting a 218 to a 230?

[Don Coatney]

I started a similar thread to this in another section of the forum recently,

http://mopar.pairserver.com/p15d24ph_forum/index.php?/topic/32356-218-to-230-flathead-how-much-real-difference/

 

 

Perhaps a moderator can combine this thread with the one you mentioned?????

[TodFitch]

Perhaps a moderator can combine this thread with the one you mentioned?????

One thread is on the truck side, the other is on the car side. Merging makes sense to me but which forum should the result live in?

[Don Coatney]

One thread is on the truck side, the other is on the car side. Merging makes sense to me but which forum should the result live in?

Fodder to combine the two. Makes no difference to me as I read both forums via using the View New Content same as you do.

[TodFitch]

Fodder to combine the two. Makes no difference to me as I read both forums via using the View New Content same as you do.

Yep. But I'm unsure how GTK would like this type of thing handled.

 

These two threads illustrates why I suggested to GTK that if more forums are added that they be based on function not on era or truck vs car. If we had an engine or drivetrain forum, for example, then it would be logical place for moving and merging both threads.

[48Dodger]

I think I agree with Todd on this one.

 

Forum title: 218/230/250/265 FLAT HEAD ENGINES (covers rebuilds, mods, swaps and carbs)

 

48D 

[Scruffy49]

Having driven vehicles with both displacements, stock 230 will walk a stock 218, but only by a few miles per hour. I'm cheating, picked up a runner 230 a couple years ago for $125, just need to swap it in place of the broken 218. To convert one using the 218 block? Not me, my truck has 4.78 rear gears and a 3 spd, too much machine shop money for too little gain. Would maybe hit 60 mph top end instead of 50-55.

 

Shave the head, put on a better flowing intake and exhaust, have the cam reground and call it good.