Moparts

Street/strip 340 combos and results...??

Posted By: cudadoug

Street/strip 340 combos and results...?? - 12/30/10 06:04 PM

Maybe be doing a build for a buddy for a hot street car, with the 4-5 times per year to the track. Problem is he wants to an actual 340, since it's an H-code Duster. I haven't been able to budge him on the idea of a 4.00" crank in a 340 block and no one would know...LOL!

So, what 3.31 stroke "streetable" combos are out there and what have they produced on the track?? Converter/gear/weight combos would be most welcome.

Thanks! Oh and Happy New Year!
Posted By: Bighead440

Re: Street/strip 340 combos and results...?? - 12/30/10 06:22 PM

Quote:

Maybe be doing a build for a buddy for a hot street car, with the 4-5 times per year to the track. Problem is he wants to an actual 340, since it's an H-code Duster. I haven't been able to budge him on the idea of a 4.00" crank in a 340 block and no one would know...LOL!

So, what 3.31 stroke "streetable" combos are out there and what have they produced on the track?? Converter/gear/weight combos would be most welcome.

Thanks! Oh and Happy New Year!




KB ft pistons, MP .528" solid, unported "J" heads, 273 rockers, RPM or Airgap with a 750 Holley, and headers- etc. will put you deep in the 12s (A-body- 3200lb) with maybe a 4.10 gear and a 4spd or 2500-3000stall. 15+"hg vacuum and great driveability, 3.23 or 3.55 gears and less stall will work fine, just a little slower. This is a real forgiving combo, just match everything to suit the car's usage! RB
Posted By: MR_P_BODY

Re: Street/strip 340 combos and results...?? - 12/30/10 06:30 PM

Ask Vic (S/ST 3040) he has one of the quickest I
have seen
Posted By: earthmover

Re: Street/strip 340 combos and results...?? - 12/30/10 06:31 PM

my little 340 ran ok . it was 30over with bme dome tops (11.1 comp ) and had a comp cam soild in it 282xs 520/540 j heads mild clean up work flow 240/140 at 550 and a x-cal intake with a 950 hp carb 8" turbo action verta 727 rev. mvb and 4.57 gears and 28*10.5 slicks ( had qtp street tires) and it ran a best of 7.44 with a 1.67 short time with the slicks and 7.5x with the qtp with 1.67/1.7x short times all in full body 70 duster no back seat.frame conn. and 6deg. nose down pinion angle...i feel it should have went a little faster but i sold the short block before i could work out the frontend..the car would just crack the front tire off the line but the 60' should have been better to me.. hope this help..mike also this was through the muff. With 38 total timing locked out
Posted By: Bad340fish

Re: Street/strip 340 combos and results...?? - 12/30/10 06:57 PM

I had a real good 340 combo about 14 years ago(that makes me feel old). .060 over with KB243(IIRC) flat top pistons. Good Quench and about 10.4:1 I believe. It had midly ported X heads on it with 2.05 intake valves. I ran a clevlite 298/508 flat tappet hydrualic with rhoads lifters. Mopar M1 single plane with a 700 double pumper. It had hooker 1 5/8 headers with full exhaust out the stock tips. The best ET it ever ran was an 11.98@114 at 3450lbs on a 26x8.5 slick with a 1.63 60ft.

It probably had more in it earlier in its life. It was my daily driver my last year of high school. With stock port X heads and stock converter it went 13.teens@110mph on plain old radials. With the stock converter it didn't even try and spin the tires until about 3500RPM or so. The converter change was responsible for .5 and the head porting responsible for the rest. By the time it ran its best ET it was 4 or 5 years old and had an estimated 30000 miles of high school kid abuse on it and LOTS passes.
Posted By: Triple Threat

Re: Street/strip 340 combos and results...?? - 12/30/10 07:38 PM

69 340 block .030 over for 346"
Low compression cast pistons (~9.5:1 at best with my heads)
stock rods
stock steel crank
hydraulic cam 230/230 @.050 480/480 lift
Stock rockers
Stock pushrods
OOTB 63 cc edelbrocks
Air Gap
750 Holley, HP main body
1" 4 hole spacer
1 5/8-3/4 TTI's
Full exhaust, 3" x pipe, 4 dynomax bullet mufflers and tailpipes to the bumper.
904
Stock gearset
Shift kit
9.5" PTC 4600 flash (~10.5% slip)
8 3/4
30 spline summers brothers axles
3.91 gears
Cone sure grip
235/60/15 ET street radial (26x8)

The car weighs 3500+ pounds as it gets raced. It made 280hp@5800 and 280tq@4800 on a mustang chassis dyno. I usually shift at about 5600. It will pick up a few hundredths if I shift it higher, 6000 ish , but not much.

BEST MPH 108.6 with a tighter converter and a tail wind
BEST ET 12.29 @107.5 with a 1.65 sixty foot

I got the engine and trans used with unknown parts, how many miles or abuse no one knew. I made 25 runs with the stock heads, they were tired and needed help. So I put the Edelbrock heads on it and made 125+ runs. Tore it down, everything checked ok, polished the crank, fresh hone, new rings and bearings. Since then I've put another 4-500 runs on it and countless street miles (abuse), I've driven the car to work every day this week so far, 26 miles round trip into the heart of Seattle and its still kicking. Plenty of power to merge with traffic. The Engine builder keeps harping on my to take it apart again for a check up

FWIW the 904 is untouched from how I got it. Added a cast aluminum deep pan, and the converter was changed to the PTC.

Not the fastest, but it has worked well for me and has proven to be reliable. For a short stroke, low torque, and low budget engine in a heavy car I can't complain.
Posted By: justinp61

Re: Street/strip 340 combos and results...?? - 12/30/10 07:53 PM

.030 over 340, Eagle SIR rods, Ross flat tops, balanced, ported Edelbrocks, 11.2-1, Hughes 3742 hydraulic, 237/242, .587/.592, Weiand X-Cellerator, Quick Fuel Q-750, TTI headers, 727, 9.5" 4400 converter, 4.30 gears with 275 ET Street Radails. It went 7.24 @ 95.02 with a 1.53 60' on pump 93 in a 3240# street/strip 69 Dart. The same short block went 7.60 with ported iron heads, 10.3-1 and a Performer RPM intake with out much tuning before the head swap. I ran 3.91s at first, the change to 4.30 only picked up .01 The cam pulled hard from bottom to top, it liked to be shifted at 6400.
Posted By: thedriver

Re: Street/strip 340 combos and results...?? - 12/30/10 09:14 PM

347 ci
eddie box stock heads
air gap
750 mighty demon
4 hole spacer
hedman hedders, 2.5 exhaust.
3400 stall
285 XEHL hyd. cam, .545 lift
3.91 gear
255/70/15 street tire
3450lbs
13.5's with a 2.4 '60ft.
elevation: 6000ft.
Posted By: 76dart

Re: Street/strip 340 combos and results...?? - 01/03/11 03:37 AM

346
rhs heads 1.92
airgape
750 dp holley
kb243 pistons
285XEHL CAM .545
3500stall
8 3/4 3.91 gears
3350lbs
Have not been to the track yet,it seems faster then my 360. 12.85 with the 360.
Posted By: MIKES_DUSTER

Re: Street/strip 340 combos and results...?? - 01/04/11 03:39 AM

340, .030, stock rods/crank, Comp cams .519/.524 hyd extreme cam,X-heads with VERY LITTLE porting but port matched,2.02/1.60 valves, 1 3/4" with 3" exhaust to the rear, M-1 sp,1" 4-hole spacer and a 750dp with a pro-form body.

All in my 3250lb street duster with a 727,8" 4200 converter and 4.56 gears. I had some carb problems but still ran 12.07@108 thru the exhaust. NON-STROKER SB's can run!!!!
Posted By: 11secaarcuda

Re: Street/strip 340 combos and results...?? - 01/04/11 04:15 AM

70 Cuda 3535# with driver

1970 340 + .020" TRW pistons, actual 9.7-1 compression
stock rods
stock steel crank
mildly ported TA heads 2.02/1.60
292/508 MP cam
Stock TA rocker arms
Factory 6 barrel intake manifold
Factory 6 pack carbs tuned by me
Hedman 1-5/8" headers (the cheap ones)
Through 3" exhaust with Hoosier DOT QTP tires

Best pass on motor 12.35 @ 109 10 years ago when fresh
Best pass 2 years with a small shot NOS 11.93 @ 113 in 90+ degree heat

Its amazing what sb Mopars will run with just a little work done to them.

Attached picture 6396166-rallys.jpg
© 2024 Moparts Forums