My 340

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F21

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OK I posted this in the racers form and did not get feedback. Maybe I should have posted it here let’s see what you guys think.

OK so here’s the new set up
I’m going to be doing over the winter
340 block 30 over Forged factory stroke crank factor rods with ARP bolts, icon, pistons Lunati solid, flat, tappet 546-566 lift advertise duration 272 280 duration at 50 /243 /251
B1 cylinder heads
Hand ported have not put them on the flow bench yet I believe about 260 ish hopefully more 11.8 to 1 compression
Crane roller rockers 1.5 Edelbrock air gap 750 Holly Speedmaster distributor orange box
Trans is a 727 Reverse manual valve body, PTC 3200 stall 8 3/4 with a 391
26 x 11 Hoosier
Car weighs 3200 with me in it
So now let’s do the guessing game. What do you guys think it’ll run in the quarter-mile And estimated horsepower
 
Don't the B1 heads have a W5 pattern intake manifold? Is you Air Gap redrilled for those heads? I'm thinking high to mid 11's if the manifold is ported to match, but a single plane would probably a better choice.
 
F21 said:
B1 cylinder heads
Hand ported have not put them on the flow bench yet I believe about 260 ish hopefully more
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260 ish is the stock rating.
F21 said:
So now let’s do the guessing game. What do you guys think it’ll run in the quarter-mile And estimated horsepower
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It all depends on the heads, if your only 260 ish cfm, I'd guess around 475+ hp.
 
there are two different types of B1 cylinder heads mine accepts standard intake

If 260 is in stock form, hopefully 270-ish
 
260 does seem low for the B1/BA heads with their 2.08 intake valves. I imagine there are some dramatic flow numbers in those heads with a minimum amount of work if you can find someone who’s experienced with them. The cam LSA for this combination is dead on based on the 128 formula and 11.8 compression. There’s probably some better cam choices out there. But without actually knowing how good or bad the head flow numbers are, I wouldn’t deviate from it. There’s no doubt that there is low 11 second potential for that build, but it may take more cam / gear / converter than what you are presently planning on. It will definitely be interesting to see what numbers it turns once you get the tune and traction optimized, I’ve known of less to go faster than my guesstimate.
 
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Very close to my setup 11.90 on a good day. You need more gear to get a 340 to wind out. 4.56 28" tire worked the best for me. A 4.30 26" tire also works good. I ran 11.74 today with a 4.10 26" tire. I'm putting a 360 in my car shortly and put the 4.10 in for the new motor.
 
Dan the man said:
318willrun did a mild 360 and it ran in the 12.80's. If that 340 doesn't run better then 12 that's sad
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Love ya like a brother so do be offended…

For someone who doesn’t have a car…….. I’d STFU!

Do so add in your two cents when you have actually done something besides cruise the forum reading everything & complaining about not having a car dispite turning many many many cars down.
 
I wanted to stay with the 391 because I still drive the car to work cruising at 50 it turns 3000 but was thinking of upping the tire size
 
I think these days if a car doesn't run in the 9s people for some reason don't think it's fast. But a legit 11.5 car is still damn fast and in solid territory.

With the duration numbers you have and those heads it seems like it could do pretty good.

Couple questions...

1. How come you aren't having the heads worked? That's pretty exotic stuff to leave stock.

2. How come the dual plane? I usually go with dual plane but in this case it seems mismatched.

3. Again with that cam it needs more stall

Edit: I misread the cam specs I thought I read duration at 50 those were the advertised numbers.
 
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The heads have been worked over pretty good, but by hand From back in the day
The dual plane I figure will be better all around on the street
I do have a Victor 340 single plane so maybe that is something I can play with
 
JMO, but 3200 seems a little low for a converter for that combo.
 
What kind of car are you working on here? You mentioned it's 3200lbs...
What is it..Dart/Duster? IMO you should be using a single plane with your combo. I have a ported/gasket matched, Victor 340 intake manifold on my stroked 340 (418") and I drive my Duster on the street. :steering:
 
OK, have not posted in a while. Got this engine together. Timing set at 20 and 34 total.
And I must be missing something this thing does not feel any different kind of a dog
I thought this combo was pretty legit, but turns out I guess not so much
 
Hold on, your converter stall is pretty low. My guess is after filling out the converter spec sheet you would get 4800+ stall recommendations. You don’t have the CI or gear to get it moving. Does the 904 have the low first gear set? Never mind 727.
 
F21 said:
I think I’m going to advance the cam
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What's the ICL at now? You should be in at 106. What 750 do you have? Are you capable of tuning it? I run 28*initial 34*total timing. Air gap works very well with your rear gear /converter.
 
OK, well I found an issue here tip broke off a push rod number six intake Valve was not opening. so running on seven cylinders, kind of hard to feel a misfire with the camshaft. Replace the push rod feels a lot better hahah now I will start working on fine-tuning.

IMG_1500.jpeg
 
F21 said:
OK, well I found an issue here tip broke off a push rod number six intake Valve was not opening. so running on seven cylinders, kind of hard to feel a misfire with the camshaft. Replace the push rod feels a lot better hahah now I will start working on fine-tuning.

View attachment 1716267309
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What caused the failure? Something did that. You better figure out why that happened or it will do it again.
 
Is that pushrod 8" long? I've always ended up using a pushrod in the 7.2 - 7.3 range. I having never run the heads you have but I would definitely be looking into pushrod length and valve train geometry.
 
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