Is anyone here old enough to remember what D/Modified Production cars ran in the mid 1960's? Did they run flat tappet or roller cams in M/P back then? Found this pic in an old book and though it would be cool to build a tribute engine. Just wondering what the performance potential might be. I have a 273 core but might use a 318 just b/c it's easier (cheaper) to get a set of forged 318 pistons. Not really interested in making it a 360 or a stroker.
Vintage drag race question
- Thread starter glockr
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rmchrgr
Skate And Destroy
This blurb is from a Mecum auction but sounds plausible.
"Dodge’s normally-aspirated, high performance 273 was rated at 235hp. The extra 40hp the D/Dart produced was basic hotrodding. Off the shelf speed shop bolt-ons included Racer Brown valve springs, a Camcraft 284-degree .500″ lift cam, Doug’s Headers, and a Holley 4160 bolted to the stock intake. All were equipped with the A-833 4 Speed and a Hurst shifter, Weber clutch components, and an 8 3/4 Suregrip with 4.86 gears. Unavailable for this car were air conditioning and a warranty. There were no external badging or markings to note the D/Dart package over a regular Dart GT."
Seems the one big difference between the general D/Dart description above and the Ron Root car from the magazine in the first post is the dual quad intake.
"Dodge’s normally-aspirated, high performance 273 was rated at 235hp. The extra 40hp the D/Dart produced was basic hotrodding. Off the shelf speed shop bolt-ons included Racer Brown valve springs, a Camcraft 284-degree .500″ lift cam, Doug’s Headers, and a Holley 4160 bolted to the stock intake. All were equipped with the A-833 4 Speed and a Hurst shifter, Weber clutch components, and an 8 3/4 Suregrip with 4.86 gears. Unavailable for this car were air conditioning and a warranty. There were no external badging or markings to note the D/Dart package over a regular Dart GT."
Seems the one big difference between the general D/Dart description above and the Ron Root car from the magazine in the first post is the dual quad intake.
I wouldn't use these as a formula to imitate, unless you want the drivability of a race car, back in the day 1 hp per cid was a fairly radical engine now days you can do it fairly mild, heads is the biggest factor in doing this, heads that make good power with mild cams is gonna be more streetable than the other way around. Next main problem is rpm and gearing needed to make decent power numbers, depending on your goal 0.9:1-1.2:1 hp per cid is a reasonable range, thats peak power in the 4700-6300 rpm range give or take. I'd would look into running magnum heads or at least LA 360 heads on a 273. 318 can run pretty much anything.
But if you want a rowdy 273, needs 6000-7000 rpm with deep gears by all means
Put in a stout solid cam with 10:1 cr and stock ish heads.
junkyardhero
Well-Known Member
are you also thinking of building and campaigning a car? or just a motor or car for S&G's?
two totally different builds... many different approaches to either...
no matter how you slice it that intake is a chunk of change though!
two totally different builds... many different approaches to either...
no matter how you slice it that intake is a chunk of change though!
I want to build a similar looking engine for my 66 Barracuda. Already have the intake and valve covers, just kind of curious as to what these (D/Modified Production) cars ran back in the day to have a number to shoot for. No strips around here and the car isn't nice enough for S&G's, so just a fun weekend street ripper.
junkyardhero
Well-Known Member
if that's the case, i say build it with the 273 you have (or if you can get a 318 cheap as chips). snap on some nice heads (small valve 360's), scoop up the manifold and a pair of carbs, knock on the correct valve covers to complete the look.
if you build it out with reasonable compression and cam-- say like a a 268-- then it should have plenty of yowl when you twist her tail.
273 mentioned up thread that what they built then was for a dedicated race car. if you want something that exhibits those characteristics, then by all mean copy what was done then. my feeling is that you can have something fun that's not wound up so tight as to be a pain in the *** to drive and maintain by carefully selecting more "modern" components that work together to deliver acceptable power.
but if it's just the look and sound you're after, then a thumpr with some headers will get you half way there, with the dual quads and some period correct valve covers to finish it off.
12.91@106 full race
stock with slicks 14.3ish 94 mph
headers and a tune 13.90s
stock with slicks 14.3ish 94 mph
headers and a tune 13.90s
1966 Dodge D/Dart Super Stock
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rmchrgr
Skate And Destroy
I agree with this.
Unless you're trying to replicate the car and it's period performance as closely as possible, there's no need to follow an ancient performance recipe. As alluded to above, you can make it look and sound the part easily enough without tracking down all the "period correct" internal pieces.
Any modern cam profile that takes advantage of faster ramps should easily outperform a mid-'60s grind even in a mild combo.
Coffee&Cars
Well-Known Member
I actually saw one of the D/Stock Darts back in the day. My brother hauled my butt down to a Chryser dealer in Akron, Ohio to show it to me. He wanted to buy it but dad would not sign the papers! Good thing too. It was like a body in white. No options. It had the 4-speed, duel quads and camshaft change already done. The headers were in the trunk. It was kool!
Coffee&Cars
Well-Known Member
If I remember this combo was said to make 275hp.
Scamp Rhonda
Well-Known Member
D/MP was 12.79 in 1967
junkyardhero
Well-Known Member
hot damn! robert nance! a quick google-fu shows he drove B bodies but wow...
some digging showed he also campaigned a 65 valiant with an injected nitro hemi. that, if i'm parsing the data correctly, was capable of running deep 9's at 150 as an average.
some digging showed he also campaigned a 65 valiant with an injected nitro hemi. that, if i'm parsing the data correctly, was capable of running deep 9's at 150 as an average.
ddartdude
Well-Known Member
The only things the same on the Roots engine and a D/Dart engine would be the connecting rods. The Roots has 12.5 pistons, higher lift cam, different crank, larger valves, heavier duty valve springs, lightweight fan...... And they both run around 12.92 @ 105.
ddartdude
Well-Known Member
What dealership was it at in Akron? I have a registry of them and don't have one listed as going there.
MILO
Well-Known Member
Coffee&Cars
Well-Known Member
Don't remember the name. it was located (at the time) across the street from St. Thomas hosptal on N. Main St. in Akron. Ohio. It really was a race car with lic. plates.
ddartdude
Well-Known Member
The car that ran the 12.4 et and 111 mph was the D/Dart campaigned by Coronet Dodge. These were both AHRA class records back in 66. They were not NHRA times.
AHRA allowed hydraulic cams, larger valves and springs, duel carbs, 280 ci engines. Can't forget the hood scoops.
AHRA allowed hydraulic cams, larger valves and springs, duel carbs, 280 ci engines. Can't forget the hood scoops.
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