The Little 340 that could

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MRL Performance

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Here is our latest 340 build. Pretty mild, but its a cruiser not a race car. We used a few things the customer had and wanted to re-use, like bone stock late 70's smog type heads, stock crank, 340 block, ect. We even used a Used roller cam from another build that needed more HP, good fit for this one. So here is the run down

340 block 30 over
Forged flat top Speed pro pistons, .040 out of the bore!
Stock heads with HP 2.02/1.60 valves Special valve job, no porting, just a little blending
Stealth intake
HR cam with 218/228 duration .480 lift at valve
Stock rockers
SCAT rods(saved 130g over stock, each!)
Proform 750 carb with choke
Stock type dist recurved
FBO ignition box
9.40 to 1 compression

It fired right up and it ran nice and smooth. Idles well at 800-850rpm pulling 15-16in vacuum. Snappy throttle responce and kind of surprised men on the power. We wanted 350-375HP and the torque would be what it would be.

It peaked at 395HP at 5500rpm, yes 5500rpm! Thats pertty good for a 340 with stock heads and no port work and not much of a cam to speak of. It still pulled hard to 6000 making over 380hp.

Torque, well you know 340's have a very short stroke and are not know for making any. This one made a showing though. It peaked with 399TQ at 4100rpm. Pulls we from 3000-5750 and it never dropped below 350TQ. It hit 390TQ at 3500rpm and carried it all the way to 4800rpm. Thats a nice "curve" for a mild 340.

Im supper happy and the customer is going to get and eye opner after he swaps out the /6 and drops this little guy in. That 7 1/4 rear has GOT TO GO!!!!

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That is impressive and should be a sweet cruiser:)
i guess that little 340 wont need any more than some 3.5-3.7:1 gears in the rear and a nice 2500rpm converter to be a real nice and fun thing:)
 
LOL, that rear axle is indeed going to 'go'. Sounds nice for the simple heads.... and for the torque, the SCR is at a good level. I'm a fan of the lighter rods and rotating assembly.

I'd like to be in the car when the customer uses just 1/2 throttle for the 1st time.... woo hoo!
 
I just wondering ... what would a build like this cost ???? You say 400 hp and roughly 400 tq..... on this mild build .... SO if you up the cam , and ported the heads , would you say the final #'s would be roughly 500 tq and 500 hp? if these would be the final #'s just adding a port job and better camshaft ... why build a stroker ?

Mike you have great reading threads ,,, thanks
 
Yep this 340 is going into my Dart. Like Mike said i wanted an engine i could drive to Carlisle and be able to burn the tires off at will lol. that is what Mike built exactly. I cant wait to get the slant swapped out and get this in its place. I will be hooking my 833 up to it and yes the 7 1/4 will be swapped out soon after lol. I plan on documenting the entire swap on here in a new thread. Finally my Dart will be as fast as she looks.
 

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66Dartdriver said:
Yep this 340 is going into my Dart. Like Mike said i wanted an engine i could drive to Carlisle and be able to burn the tires off at will lol. that is what Mike built exactly. I cant wait to get the slant swapped out and get this in its place. I will be hooking my 833 up to it and yes the 7 1/4 will be swapped out soon after lol. I plan on documenting the entire swap on here in a new thread. Finally my Dart will be as fast as she looks.
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That '66 looks great! Is it blue like it looks or is it actually black with the blue sky reflecting?
 
I just love those early A body Darts, look cool and you dont see to many of them. maybe, someday you can drive it up here and take me for a ride. Ill bet it gets 20mpg if you gear it right. My 69 Dart had a 360 with just a tad more torque(430) and a 2.76 gear, it got 20mpg highway.
 
rrvolare said:
I just wondering ... what would a build like this cost ???? You say 400 hp and roughly 400 tq..... on this mild build .... SO if you up the cam , and ported the heads , would you say the final #'s would be roughly 500 tq and 500 hp? if these would be the final #'s just adding a port job and better camshaft ... why build a stroker ?

Mike you have great reading threads ,,, thanks
Click to expand...

I built one a few years ago for a Member on here(golduster) his 340 had RPM heads(stage 2 ported) a little bigger cam(227/231), made 470/450.

Cost to build one of these is going to be around $6700 if you supply the 340 block. Of course it could also be done with a 318 or a 360 as well.
 
Nice build 66Dartdriver! Your going to be a very happy guy when you crank it up that first time.
Glad to see the Proform 750 on it. My son and I just saw an increase of exactly 10hp with that carb over two different 750 Holleys. It was dyno'd right out of the box!

BTW, what oil pan is that? Doesn't look stock.

Good luck with your swap and keep us informed.
 
rrvolare said:
I just wondering ... what would a build like this cost ???? You say 400 hp and roughly 400 tq..... on this mild build .... SO if you up the cam , and ported the heads , would you say the final #'s would be roughly 500 tq and 500 hp? if these would be the final #'s just adding a port job and better camshaft ... why build a stroker ?

Mike you have great reading threads ,,, thanks
Click to expand...

The reason to build a stroker is it make the same power at a much lower rpm needing less gearing and stall if those things don't bother you then none really.
 
Nice work Mike. I love real world builds, it proves matching parts pays out.

Anything done to the Stealth? I know they have small port windows that can be opened up.
 
360DartGT66 said:
That '66 looks great! Is it blue like it looks or is it actually black with the blue sky reflecting?
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its the original EE1 dark blue metallic i think its a great color because as you said sometimes it looks black.
Mike this car is definitely taking some road trips ill let you know when i can come up to your place and give you a ride lol
 
MRL Performance said:
I built one a few years ago for a Member on here(golduster) his 340 had RPM heads(stage 2 ported) a little bigger cam(227/231), made 470/450.

Cost to build one of these is going to be around $6700 if you supply the 340 block. Of course it could also be done with a 318 or a 360 as well.
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Yes! Golddusters engine is really nice and runs well on the track and street. Talking with him on it, well, it was easy to see he is really stoked about it even after a good long time having it in the car.

I noted the build and it is very similar to the 360 I'm building for the wifes '67 Cuda now. Zero deck Speed Pro slugs (Like the KB-107's) Letter heads with similar work, Lunati HR of similar specs, etc... Looking forward to 3.55's and a 2500 stall in the 904.

$6700 is a very reasonable price Mike. :glasses7:
A very nice performer for sure.
 
MRL Performance said:
Im supper happy and the customer is going to get and eye opner after he swaps out the /6 and drops this little guy in. That 7 1/4 rear has GOT TO GO!!!!
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for what its worth, my 7 1/4 lasted less then three days behind an MRL motor :burnout:
 
diymirage said:
for what its worth, my 7 1/4 lasted less then three days behind an MRL motor :burnout:
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Ok I'll see if I can get mine to last 4 days lol I am hoping to baby it all summer so I can save some money up again for a 8 3/4 lol I may be in trouble...
 
66Dartdriver said:
Ok I'll see if I can get mine to last 4 days lol I am hoping to baby it all summer so I can save some money up again for a 8 3/4 lol I may be in trouble...
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The problem is that every time you itch that throttle, it will make you smile. itchy feet turn into LEAD Feet.....Boom. Try to keep away from full throttle starts and it should last a day or two longer:burnout:
 
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