218 performance bump

[Al Peterson]

I am thinking about doing an engine rebuild in the next year, has anyone done one with a mild bump in power?  I'm not looking to race or any such thing, just looking at get a few more ponies so the powerband is more highway friendly.  My ultimate goal is to keep this truck as stock as possible but with mild engine mods, I don't really have any desire to jump up to a 230...for now anyway.  I do have a generous offer (free) for a 230 but I am not sure what other mods I'd need to make if any on a '47 WC to make that conversion work.  So, in the mean time I am looking for suggestion of tried and true remedies for the 218.

 

Al

 

[jeffsunzeri]

You get extra HP just from running high octane fuel with a small advance of the timing.

 

You'll get the biggest and best performance improvement from a dual exhaust. Next will be a head shave for a compression increase, using 91(or higher) octane fuel, followed closely (or at the same time) by dual carburetors.

 

Your WC will love having a 230 under the hood. It's a bolt in replacement for the 218.

Edited August 15, 2018 by jeffsunzeri

[Young Ed]

1 hour ago, jeffsunzeri said:

You get extra HP just from running high octane fuel with a small advance of the timing.

 

You'll get the biggest and best performance improvement from a dual exhaust. Next will be a head shave for a compression increase, using 91 octane fuel, followed closely (or at the same time) as dual carburetors.

 

Your WC will love having a 230 under the hood. It's a bolt in replacement for the 218.

or while you're rebuilding use the 230 crank and rods in your 218 block and no one but you will know you did it

[NiftyFifty]

230 a direct drop in, but honestly the difference in hp from a 218 is pretty negligible.  Get yourself a set of  dual exhaust headers, shaving the head can definitely help and may need to be done anyway, and my best upgrade was going to a 2 barrel carb instead of the stock single.  

[pflaming]

12 hours ago, NiftyFifty said:

upgrade

 

my best upgrade was going to a 2 barrel carb instead of the stock single.    

which carb did you use? 

Edited August 16, 2018 by pflaming

[NiftyFifty]

1 hour ago, pflaming said:

 

my best upgrade was going to a 2 barrel carb instead of the stock single.    

which carb did you use? 

 

Used this one, and an adapter plate from Trans Dapt, which I had to do just a bit of grinding on to fit, but it's working fantastic, and I never touched a thing on the carb, worked great out of the box.  I did a thread on it "fingers crossed carb upgrade" I think it was called

[pflaming]

Nifty, TKS, I'm going to get one and soon. I have a split  exhaust manifold, and an overdrive, so with a 2 barrel carb and an electronic distributor I should have a very nice truck. 

 

But must finish the Suburban first, rear axle seals and new rear brake cylinder kits next. 

Edited August 16, 2018 by pflaming

[NiftyFifty]

Yep, I did the electronic ignition as well...not really any noticeable difference with it, but no more messing with points is enough of a benefit

[jeffsunzeri]

15 hours ago, NiftyFifty said:

230 a direct drop in, but honestly the difference in hp from a 218 is pretty negligible.  Get yourself a set of  dual exhaust headers, shaving the head can definitely help and may need to be done anyway, and my best upgrade was going to a 2 barrel carb instead of the stock single.  

What sort of benefits did you get with the 2BBL carb? Better gas mileage? More pep? Better acceleration, top end? 

[pflaming]

For me the electronic distributor, with the elevation change from 300' to 6500' in 30 miles will be nice. I like to drinker it to the mountains.

[Plymouthy Adams]

40 minutes ago, pflaming said:

For me the electronic distributor, with the elevation change from 300' to 6500' in 30 miles will be nice. I like to drinker it to the mountains.

 

 

 

the effects of your drinking is showing......

[JBNeal]

At least one of my projects will be getting a 2bbl, dual exhaust + shaved head + 180F thermostat with a PCV system...the factory setup is to maximize economy and power...I recall later flatheads had boosted compression by shaving heads for upwards of 20hp gain, and the rare 2bbl option also increased hp but improved response at the cost of slightly decreased economy.  The 180F thermostat reduced sludge formation, and the PCV system put combustible crankcase fumes back through the carburetor...and if done right, only the trained eye will notice these modifications

[NiftyFifty]

2 hours ago, jeffsunzeri said:

What sort of benefits did you get with the 2BBL carb? Better gas mileage? More pep? Better acceleration, top end? 

 

Everything but better fuel mileage...that is a bit worse, but the power gains far out weigh that difference 

[pflaming]

On Hwy driving at 60 mph, how much mileage drop?

[greg g]

Your fuel economy could likely increase due to a more efficient engine. And f you need to rebuild an engine, why not do the 230? It going to cost the same.  And as far as there being no difference,I disagree. My 218 was rated @ 97 HP, the 230 l put in was rated at 125. If you can't feel 28 more horses, something ain't working in the seat of your pants.  And with suitable changes mentioned, the rebuilt and modified 218 will behave like a stock 230, a built 230 is even more effective.  If it were me the 230 is where l would start.

[Reg Evans]

What Greg Said !

[NiftyFifty]

3 hours ago, greg g said:

Your fuel economy could likely increase due to a more efficient engine. And f you need to rebuild an engine, why not do the 230? It going to cost the same.  And as far as there being no difference,I disagree. My 218 was rated @ 97 HP, the 230 l put in was rated at 125. If you can't feel 28 more horses, something ain't working in the seat of your pants.  And with suitable changes mentioned, the rebuilt and modified 218 will behave like a stock 230, a built 230 is even more effective.  If it were me the 230 is where l would start.

 

Only if his 230 is post 55, and 125 came in a 56 engine...so you would need to know all of that as well and be sure what your building.  I’m not sure what changed, possibly head clearance and valve or cam changes, but the 54 and older 230 are all around 110 or less hp, very close to the 218.

 

I would build whichever is the cleanest and most un molested block to start, if it’s already bored 30 + over you may want to use a different block

[Al Peterson]

Thank you to everyone adding their input, truly appreciate it.

 

 

question:  is the 230 the same as the 218 except for the crank and rods?

[ggdad1951]

22 hours ago, Al Peterson said:

Thank you to everyone adding their input, truly appreciate it.

 

 

question:  is the 230 the same as the 218 except for the crank and rods?

 

same block, same head.  Yes different internals.  You cannot tell the difference visually from the outside of the engine.

[NiftyFifty]

As long as both are 23” block FYI, some 218’s are 25” but that was mostly Canadian 

[Bob Riding]

On 8/16/2018 at 5:58 AM, NiftyFifty said:

 

Used this one, and an adapter plate from Trans Dapt, which I had to do just a bit of grinding on to fit, but it's working fantastic, and I never touched a thing on the carb, worked great out of the box.  I did a thread on it "fingers crossed carb upgrade" I think it was called

Bought the carb and adapter, but must have purchased the wrong adapter because although it fits perfectly over the 1 1/2" intake opening, it isn't wide enough to attach to the bottom of the carb. Do you have the model of adapter you used?

[greg g]

So All has been quiet about this and the suggestions.  Have you assorted through the input and made a decision?  For better highway cruising a change in rear end should also be part of your planning.

[Radarsonwheels]

Mine had a repop weber 32/36 carb from the stovebolt guy. It started and ran amazing and the electric choke worked perfectly. The rest of the recipe was a shaved head, repop fenton dual exhaust manifolds, 3.73 gears, t-5 trans. The trans was actually useless past fourth gear because my steering box was too sketchy over 50mph.

[Radarsonwheels]

To add to the options and confusion haha anyway the driveline worked excellent and it probably ran hard over 3000 but I always shifted at 3200...

[NiftyFifty]

This is the adapter plate you have to use on the autolite/holly style carb