And trans. I see a lot of people running big double pumpers on these small displacement small blocks.
How to get 400 hp out of 1971 340 .30 over
- Thread starter Jays71 demon
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doogievlg
Well-Known Member
I believe compression was 10.5:1. It’s 3:30 in the morning and I’m trying to get my 9 month old back to bed so you’re just going to get a pic of the cam card lol.
Divenut
Well-Known Member
Yep. Blink and they're 23 yo adults....
Now I know what my parents meant when they said they wish they could the. The clocks back to when I was just a baby/kid.
My oldest is about to turn 30. My youngest recent joined the USAF. He’s no longer just a big boy!
When they were small, they were a tough job but the best job to ever have.
doogievlg
Well-Known Member
Hardest job I’ve ever had and it’s going to get more difficult as time goes but I got my fingers crossed he will be working on the Dart with me or hunting and fishing one day.
Summit has a "top end kit" they claim it makes 417 HP. Not cheap, basically just heads and a cam. Just sayin.
Edelbrock 2049 Edelbrock Total Power Package 417 HP Small Block Mopar Top-End Engine Kits | Summit Racing
Edelbrock 2049 Edelbrock Total Power Package 417 HP Small Block Mopar Top-End Engine Kits | Summit Racing
You need a 750 carb for a 340 to rev to 6500 rpm. Nope. Not according to these guys.....
See below. A bit hard to read, says this:
'.... would rev the 340 UP TO 6500 RPM right now with the hyd lifters without a whisper of valve float or ign miss.....Chrys engineers have obviously got a BEAUTIFUL combination of valve &port size, camshaft and CARBURETION here. '
Notice also that the 340 made 20 hp MORE than the advertised 275, using a little ole 625 AVS carb....while other engines made LESS hp with 750/800 QJ carbs. Hmmmm....
See below. A bit hard to read, says this:
'.... would rev the 340 UP TO 6500 RPM right now with the hyd lifters without a whisper of valve float or ign miss.....Chrys engineers have obviously got a BEAUTIFUL combination of valve &port size, camshaft and CARBURETION here. '
Notice also that the 340 made 20 hp MORE than the advertised 275, using a little ole 625 AVS carb....while other engines made LESS hp with 750/800 QJ carbs. Hmmmm....
I GOT 410 HP OUT OF A 340 30 OVER Mahle flat top pistons Ede heads 11:1 compression not sure the cam think it was 573 lift . My new 340 makes a bit more 440 hp , using Trick flow heads Molnar H beam rods speed pro flat top pistons 10.5 compression , could not find the nice light Mahle pistons , 1.6 rockers ported Ede dual plane intake and a 750 Street Demon . 400 out of a 340 is easy with the right parts and builder
Machining these days and most parts are much better . Back in the 70's me and a friend both bought 340 Darts one was 1/2 a second slower no matter who drove it . back then it was pure luck if you got a 340 . They just slapped them together , did not care s long as they started and rolled off the line , then talk about panel alignment , or lack of
Machining these days and most parts are much better . Back in the 70's me and a friend both bought 340 Darts one was 1/2 a second slower no matter who drove it . back then it was pure luck if you got a 340 . They just slapped them together , did not care s long as they started and rolled off the line , then talk about panel alignment , or lack of
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jason's duster
Well-Known Member
Taking my 69 340 to the Dyno in a couple of months.
Just curious what everyone thinks since we are on the topic.
.030 over TRW flat tops 10.5:1
X heads
RPM Air Gap
Holley fuel pump
Holley 670 DP
TTI Headers
FBO Ignition
This is just going to be an engine dyno. Car is not ready yet.
I’ll post Dyno sheet when it’s done to see how close everyone is.
Thanks in advance.
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junkyardhero
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ir3333
Well-Known Member
532 lift cam and x heads
350/360
350/360
No offence, but ditch the hydraulic cam. Call a Mopar grinder like Howard's, Delta, Oregon cam grinding ect. Secondly pay attention to lift at .200". Chrysler heads are limited in cfm if your using oem castings. Save your $ and get a stick ground for maximum velocity. Look up the La head cfm reports on this site you'll get the picture.
Understand that there are Super Stock racers running 1.88 valves that would put many of us on the trailer! In the end, be prepared to turn that mill 6500~.
Is the casting modified by Allstate? Dig the removable air bleeds!
coloradohill
Well-Known Member
I believe so, from their website, 550 HOLLEY TUNNEL RAM CARBURETORS - Allstate Carburetor
Custom-built Holley 550 cfm carburetors. For Hemi motors, Inline tunnel ram, Jet boats, etc
550 HOLLEY TUNNEL RAM CARBURETORS. This is an unique set of custom 550 cfm mechanical secondary. These are only available here. These highly developed carbs are also the hottest set of tunnel ram carbs to date. Because of the design and claibrations the quick throttle response will throw you into your seat. Also they have a Very clean idle quality. YES they are MECHANICAL SECONDARY carbs. They are similar to the Holley 9776. Choose your finish from the drop-down menu. ACFI Polished finish as shown or the classic Holley Gold. All Non-stick gaskets and .110 adjustable needle and seats. Also featured in this set of carburetors are custom secondary metering plates. Because of this the secondary main jets are removable as well as the primary. Thus making these more tunable to your engine.
It took about a week and a half to ship once I ordered them. Two guys work there Jim and Jarred. When I called to order them they told me that they would have to build them before shipping.
Looking forward to seeing how they do this summer.
Newbomb Turk
Well-Known Member
coloradohill
Well-Known Member
I don't, but I will call them tomorrow to find out. I had them shipped to my builder and have not laid my hands on them yet.
I'll update this information once I can.
Newbomb Turk
Well-Known Member
I think it will be interesting to see the sizing. I'm not sure if they get that flow rating by those sizes or if the are using a straight leg booster to get that flow number.
coloradohill
Well-Known Member
I'll ask them. I have been running 660's for the last few years, installed annular boosters, and a lot of jet changes to get them somewhat tuned for this altitude. I wanted something better without going to fi. I hope these are the ticket.
Newbomb Turk
Well-Known Member
Initial tuning on TR carbs is enough work. Tuning for altitude is a whole other game. I've tuned for about 4500 feet coming from sea level. I was shocked at what I had to do. I can't imagine tuning to 8000 or 9000 feet.
coloradohill
Well-Known Member
I'm at 5000, using an AFR meter helps, and of course, lots of patience.
I will say though, this engine starts hot or cold better than any other setup I've had on it. Was going to abandon the TR for a six-pack but decided against that after running the six-pack a few times and comparing the difference.
I will say though, this engine starts hot or cold better than any other setup I've had on it. Was going to abandon the TR for a six-pack but decided against that after running the six-pack a few times and comparing the difference.
Have you Spoken to Steve Taylor? Carb builder in Tx. Ran Bandemere successfully.
coloradohill
Well-Known Member
I talked to a carb builder in Texas a month or two ago. Actually his wife answered the phone but couldn’t answer many questions. I’m not sure if it was his shop or not. I’ll look it up again to find out.
Thanks
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