340 vs 340.

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Moparhead

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So me and a buddy have a wager going who’s 340 is faster. Both are identical but one thing both have forged pistons 10.5 to one compression. x heads mine have ports minor cleaned. Same rpm intake 750 carb. Only difference is mines got the hemi grind cam he’s got the 508. Always liked both cams but never got to run against each other both 340 4 speeds with 391 gears. I do have a lower first gear. Both are defiant 12 second cars. I’m buying his motor too. So I think it be fun.
 
Who's the better tuner, that will determine the winner.
Me lol. But I will be tuning both. My car is quicker out of the whole, he only ran 355 gears in it. Ran 12.70-80. With street tires. And I ran 12.45 ish with really bad leafs and street ish tire both had more in. I’m thinking driver will be key
 
You need to switch drivers and runum back to tell.


You do that and you can get your feelings hurt. My uncle embarrassed me in 1980 because I blamed my car for losing to him. He drug my butt with my car so bad it was silly. I learned a ton that day though.
 
Has anyone ever ran born cams
You do that and you can get your feelings hurt. My uncle embarrassed me in 1980 because I blamed my car for losing to him. He drug my butt with my car so bad it was silly. I learned a ton that day though.
Sounds like my dad guy can flat **** and always gets the car to hook every time. It’s truly effortless for him.
 
Decades ago Direct Connection had a list of their performance big block cams and ET results in the same 400 engine. Don't know where to find it. The differences were small increments, but improved as the cams got bigger. I don't recall the steps being much more or less than .10. (No radical, race only from what I remember.) But your "port cleaning" may overcome that. The lower first gear would also be an advantage as long as it didn't cause more wheel spin and the engine had a torque curve that would recover better from the 1-2 rpm drop.

Too bad you haven't been to a track. 60' times would mainly show how good the suspension & tires work while MPH would mainly show the overall HP.

Overall vehicle weight is also a factor. Weight distribution comes into play and sometimes adding weight to the back will reduce wheelspin enough to overcome the added weight disadvantage ET-wise. (...and add a little consistency for bracket racing.)

As pointed out, tune-up and driver ability would likely be the biggest influence on the outcome.
 
Decades ago Direct Connection had a list of their performance big block cams and ET results in the same 400 engine. Don't know where to find it. The differences were small increments, but improved as the cams got bigger. I don't recall the steps being much more or less than .10. (No radical, race only from what I remember.) But your "port cleaning" may overcome that. The lower first gear would also be an advantage as long as it didn't cause more wheel spin and the engine had a torque curve that would recover better from the 1-2 rpm drop.

Too bad you haven't been to a track. 60' times would mainly show how good the suspension & tires work while MPH would mainly show the overall HP.

Overall vehicle weight is also a factor. Weight distribution comes into play and sometimes adding weight to the back will reduce wheelspin enough to overcome the added weight disadvantage ET-wise. (...and add a little consistency for bracket racing.)

As pointed out, tune-up and driver ability would likely be the biggest influence on the outcome.
12.45 with a 1.7 60 ft. Have not ran it with super stock leafs might just rebuild stock leafs. Doesn’t spin too bad in first. It defiantly bites harder than a traditional a833
 
We both think mine would have gotten his out of the whole. But he may have got it a bit at the end.
 
The 340 is always my first choice and certainly is the clear winner in this competition. Is that the old 292/508 purple shaft? Loved that cam, had it in my first 340.
 
Decades ago Direct Connection had a list of their performance big block cams and ET results in the same 400 engine. Don't know where to find it. The differences were small increments, but improved as the cams got bigger. I don't recall the steps being much more or less than .10. (No radical, race only from what I remember.) But your "port cleaning" may overcome that. The lower first gear would also be an advantage as long as it didn't cause more wheel spin and the engine had a torque curve that would recover better from the 1-2 rpm drop.


Here ya go, Loco

cams dc 002.JPG
 
Lets throw this in the mix. See what happens.

340.jpg
 
The 340 is always my first choice and certainly is the clear winner in this competition. Is that the old 292/508 purple shaft? Loved that cam, had it in my first 340.
Yep 508 purple shaft verses the 474 hemi grind
 
I have used the 284/484 purple shaft in my 70 340 4 speed Duster. I really like the way it worked with the 4.30 gears. But street tire technology back in the 80’s was lousy to say the least.
 
I have used the 284/484 purple shaft in my 70 340 4 speed Duster. I really like the way it worked with the 4.30 gears. But street tire technology back in the 80’s was lousy to say the least.
How quick was the car ?
 
I bet the 474 cammed engine will beat the 508 cammed one.

If the heads are stock with the 508 engine and the 474 have work, no brainer, 474. If the 508 or 474 are installed ahead a bit, even more than recommended, that will help that mill down low/mid range for sure.

just my experience with the 508-509 cam... the 484 is just as good until the last 500 or so of RPM range. I'd rather have the 474*480*484 cams than the 508 one. Unless the smaller cams are the horrid 114LSA. :)

There are so many variables here.
 
I bet the 474 cammed engine will beat the 508 cammed one.

If the heads are stock with the 508 engine and the 474 have work, no brainer, 474. If the 508 or 474 are installed ahead a bit, even more than recommended, that will help that mill down low/mid range for sure.

just my experience with the 508-509 cam... the 484 is just as good until the last 500 or so of RPM range. I'd rather have the 474*480*484 cams than the 508 one. Unless the smaller cams are the horrid 114LSA. :)

There are so many variables here.
the heads on his 508 cam motor were bone stock other than springs.
My hemi grind is an older grind. And works well I do agree I feal like his 340. Was more of a dog out of the whole and mine was more torquey down low I made 410 hp when motor was built prob around 420 ish now I’m sure his around the same but mine made the best power at 5500-6000
 
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