Suggestions on performance upgrades for 225

[273]

When it comes to making power there's little sense to building anything smaller than a 440, but a long as you know the limitations not everything has to be the king of the streets or make perfect dollar sense. Most engine you can go with semi mild/wild cam, carb, exhaust and 3.23-3.55 gear and be happy with the performance for what it is beyond that you got to start debating if it's worth it.

The biggest problem with a 6 of any kind it has two less intake ports so the rule of thumb of 2 hp per cfm doesn't apply to a /6. You would need 33% more cfm to make the power of a V8. So a 200 cfm V8 port is said to have a 400 hp potential but that's with a lot of Cam and CR to do it with a more street able cam and CR you would need to run 10% or so more cfm. And from the ported flow numbers I've seen a /6 can barely beat stock 318 flow numbers.

 

[TF360]

Little sense to building anything other than a 440? Not true

 

[Charrlie_S]

Little sense to building anything other than a 440? Not true

Want torque/HP go see Sonny. http://www.sonnysracingengines.com/engines/sar-1005-2100-hp

 

[roccodart440]

So a 200 cfm V8 port is said to have a 400 hp potential .

Now consider SR heads for a 440 flow 290cfm.

I honestly love the 440 in an A body. I've had /6, 340 and two 440's. The 440's fit fine and in some ways better. You can put a really mild engine together and have gobs of power and depending on the setup, decent mileage too.

 

[273]

Little sense to building anything other than a 440? Not true

I'm not saying little engines can't compete but mod for mod bigger engine will win. I'm just saying when it comes to the lesser choice engines eg. /6,273/318, 383 build it to the powerband you want. The best for the streets being idle to 5500 rpm and be happy with outcome. Of course you could build it to higher powerbands so you can beat lower powerband 340/360 400/440 that up you but sooner or later your gonna hit an rpm wall.

I'm just saying on lesser engines know and except there limitations or move up the cubic inch ladder. Like a /6 even the basics hot rodding, cam, carb and exhaust isn't gonna give big results like it would on a V8. For a /6 is hard to even beat the lowly stock 273/318. Never mind a 440
Even at the same power of say 200 hp, a /6 would need to have 5.75:1 rear gear to match a 2.94:1 geared 440.

I'm not trying to persuade people one way or another that's up them to decide, just trying to help make an informed decision.

P.S. bigger engine is a little miss leading the biggest bore has the most advantage as long as you willing to gear it so a 400 is slightly better than 440 same with 340 vs 360 also including 383 vs any small block stroked or not.

 

[kesteb]

An expert has spoken, the science is settled. The only upgrade path for a slant 6 is a 440.

 

[273]

An expert has spoken, the science is settled. The only upgrade path for a slant 6 is a 440.

I'm pretty sure that's not what I said lol
Was just trying to show the OP your up against it with the /6 mainly cause of the poor head flow and need for deep gears.After probably $2000 in mods will only have an engine on par with a 2 bbl 318 not necessarily a bad thing as long as your ok with it.

And with the 440 thing just saying if you build anything less your just leaving performance on the table and probably costing more to do it and also not necessarily a bad thing.

 

[Killer6]

Not in my experience.

'73 Duster with rebuilt stock 225. The engine was set up with cast iron Super Six manifold along with a Autolite 2100. I changed out the Super Six for an Offenhauser with the same carburator.

'65 Dart, mildly built 225. changed over to the Clifford with the same carburator.I gained 2 tenths on the track and there was a noticable change in the butt-o-meter with better response through out the entire rpm range. Conclusion, the Clifford is a better over all manifold.
I also drive my Dart daily. So i have extensive experience with this combo.
The 500 AVS is a very capable carburator.

It is not a crappy 40 year old remanufactured piece of junk, with a worn out throttle shafts.

Ok,lol,not every old carb is worn out.And there is nothing wrong w/rebuilding one if
quality parts are avail.As far as the duster goes,I wouldn't expect any improvement w/a
stock eng. and that carb,and if you went from heated to un-heated w/o jetting up i'm
surprised it didn't go slower! The only one that interests Me is the dart,how mildly built,
cam,comp.,valves,etc. ? Lets see if anyone else has sim. setup and experience w/those.

 

[Killer6]

You have to realize how Clifford operates. There is no large warehouse full of parts waiting to be shipped out. They take orders, collect money and when enough orders are in, they do a production run.

Jack Clifford gave a lifeline to those w/inlines largely ignored by almost everybody
else,and I'm not going to be so quick to toss his company under the bus.That^^^^^is the
unforgivable sin in today's ondemand 3 keystrokes and I've bought it/found it world.The very
thought of waiting for something is outrageous to kids/people.Summit/jegs have us spoiled,
and no matter how odd or obscure the item,we expect one on our doorstep in 2-3 days.
I'm sure there may be operating/management/attitude issues w those who have
assumed the task of running the co.,business can be tough,and who can say what the state
of finances were/are?I'll reserve My judgement of the co. after another year or two,then i'll
weigh the feedback,hopefully more positive by then.

 

[Charrlie_S]

Agreed, when Jack Clifford was alive, and running the company it was fine. When Jack died, there was fighting over the company. I don't know the details, but I heard, employees where steeling parts and selling them on their own. Eventually Larry Millwe (?) got control. Larry was Jacks son-in-law. From what I can see, he is not a car person, he is a retailer. I have spoken to him and he does not impress me with his auto knowledge. He has been known to tell people he has a part in stock, take their money, and then have the part(s) made. This leads to a long delay.

I will say, I like the Clifford 4 bbl intake, and he is the only source for headers for the 66 and older "A" bodies, with a 225 engine.
PS: the headers do not fit wit a 170 engine. but can be modified.

 

[sfvaliant]

Nice to see another van with the slant, I've got the same stock setup on mine may also be looking for a little more power. Holds fine on highway but takes awhile to get there. Keep us posted on any upgrades.

 

[DelrayA100]

Nice to see another van with the slant, I've got the same stock setup on mine may also be looking for a little more power. Holds fine on highway but takes awhile to get there. Keep us posted on any upgrades.

Upgrades completed......

FSR Rad
Clifford Headers
Clifford Intake Mani
Webber 38/38 500cfm
Petronix HEI
2-into-1, 2.25 exhaust
Lots of other adjustments/maintenance. She runs exactly how I wanted and better gas mileage to boot. :finga:

 

[vntned]

That's awesome! I'm glad you were successful!

 

[vitamindart]

very Cool! are those Ranger wheels with AMC centers? Awesome Van!
I have always wanted one.

 

[roccodart440]

That van is really cool