Most of the mild rebuilds discussed include a 2 bbl , duals, a slightly higher than stock cam, and porting, and roughllly 9:1 comp ratio.

My plan, which keeps costs down, would be:

Keep the carter 1 bbl
dual exhaust
porting head and original valves
the stock cam and degreeing cam
electric fan
shaving block enough to get 8.5 - 9.0 : 1 comp ratio.
keep the 2.76 rear end

Woudl this combo be an improvement in mpg, and useful for every day
driving, or is the carb or cam limiting the usefulness of the other mods?

Or, should I just go ahead and do it, and see how well it works?

THanks gurus

If the engine's wearing down, a rebuild is not a waste of time. I'd imagine the duals and electric fan would make significant changes, although these days you can get high flow single exhausts at reasonable prices. Just don't get carried away with the port job; you don't want a 6,500 RPM head with a 4,000 RPM cam.

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"Mad Scientist" Matt Cramer
'66 Dart - turbocharged 225
My blog - Mad Scientist Matt's Lair

An aftermarket cam with OE lifters is not significantly more expensive than a new stock replacement. It' one of those thing that just make sense. Even leaving stock induction....what if you eventually want more, at least the cam is done.
My $.02

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225 .030
.020 off the block .100 from head
Comp 264
904 Tranny
New Ebre-ting

http://s78.photobucket.com/albums/j103/edrod01/

I have found the two barrel swap to give me better milage.

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Excuse me, does this smell like chloroform to you?

Me too - the BBD seems to give slightly better mileage than a Holley 1920. That's probably why most of the rebuild threads include a Super Six - there are not much of any downsides to this upgrade.

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"Mad Scientist" Matt Cramer
'66 Dart - turbocharged 225
My blog - Mad Scientist Matt's Lair

Are you going to do a complete rebuild, or just add the new parts?
If it were me (and it was) I would build it with a .060 stock piston (honed with block plate if possible), Mild cam (mopar 243, or similar)degreed in, milled head to get an honest 9.0-1 compression ratio (forget milling the deck) 2 1/4-2 1/2 single exhaust with low restriction muffler. Stock 1 bbl or super six. Recurve distributer.

MPG Fanatic and I did a similar engine last year (1 bbl holley), in a 64 Valiant 3 speed standard trans, and he is reporting about 27 mpg.
We also balanced the rotating assy, and no porting on the head (i don't think it is worth the effort for what you want)

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Charrlie_S
65 Valiant 100 2dr post 170 turbo
66 Valiant Signet 170 nitrous
64 Valiant Signet
64 Valiant 4dr 170
64 Valiant 4dr 225

Your replies help.

Yes, a complete rebuild. Just looking for best MPG possible, and best pep
from basically a stock motor (a 225). Not looking to race.

Now, of these cams, which would be OK for "clean up" porting and the
1 bbl, and the 2 1/4 dual exhaust?

comp 252
erson 270
mopar 243 (is this the stock mopar?)
other?

THese numbers refer to duration, right? And the greater the duration, the better the........?

ANd, the decimal numbers, e.g., .425 , refers to lift, right?
And the higher the lift the better the.........?


THanks again

I just went through the same process..........

The engine is almost broke in. I have a few things that are not tuned yet, like the distributor recurve, installing the good Aussie gaskets to eliminate some vacuum and exhaust leaks and fixing a harmonic balancer seal leak, and blocking off the EGR, but I am almost there.

I drive 128 miles a day. If I could restrain myself from getting on it so often and drive a little slower and do the above fixes, I am sure the mileage would be much higher. I find myself cruising around 70 (2700 rpm) instead of 60 (2500) rpm and passing every Mustang GT I find on the back roads. Plus town driving is kind of fun now with so much extra power. It is fun to bust the wheels loose (posi) now and then. Most folks can't believe it is a SL6 much less a fair to poorly tuned one. Once everything is finished I should take it on a trip to see what it will do. Then down the drag strip, SIR is 10 miles away to see what it will do there.

I think your rebuild is right on and your right about the cam numbers. You can cross reference with my rebuild and PM me for pictures and questions.

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Aggressive Ted

http://cid-32f1e50ddb40a03c.photos.live ... %20Swinger


74 Swinger, 9.5 comp 254/.435 lift cam, 904, ram air, electric fans, 2.5" HP2 & FM70 ex, 1920 Holley#56jet, 2.76 8 3/4 Sure-Grip, 26" tires, 25+MPG

i have a .060 over, comp cam, 4 bbl hyperpak setup, clifford shorty headers, i am not sure what size I need the exhaust to be... any suggestions on mufflers and pipe size??

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65 Coronet, 4 bbl, .060 over, mild cam.
66 Valiant, Black, 3spd, Hyperpak, headers.
works in progress...

Most folks will tell you to use a "Y" pipe to join them and one single 2.5" out the back. Saves weight, etc.........

If you have a serious build, I would try (2) 2.25" pipes with and "X" pipe for some serious power.

How big is the cam and what is the compression ratio? If it is a mild build, go with the first option.

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Aggressive Ted

http://cid-32f1e50ddb40a03c.photos.live ... %20Swinger


74 Swinger, 9.5 comp 254/.435 lift cam, 904, ram air, electric fans, 2.5" HP2 & FM70 ex, 1920 Holley#56jet, 2.76 8 3/4 Sure-Grip, 26" tires, 25+MPG

I'm right in the middle of this process as well. I went with Dan's recommendation of a Mopar 244 cam, which is available from Doc. Unfortunately, I don't have it all together yet, so I can't tell you how I like it.

I also bought a Dutra front manifold and am fabricating the rear from the original.

-Moose

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1966 Clark Cortez, Industrial /6