340 Build

Is this a good set up for my 340

  • is the cam too big

    Votes: 0 0.0%

  • is this a bad combo

    Votes: 2 100.0%
  • Total voters
    2
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disco

disco

Daddy Dave
Joined
Oct 8, 2014
Messages
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Location
St Thomas Ontario
Hi I would like some help with a motor Ive just done with the help of Dave Hughs, I bulit! its a 340 bored 40 over, Icon pistons,hastings rings, 10-1 compression,63cc Edlebrock Alum rpm heads 202 & 1.6 valves , 1.6 Hughes alum rockers, hughes pushrods, 750 Holley track warrior carb, pro billit msd dist, Msd 6al box, Msd wires and champion plugs, Hooker pro comp long tube headers with flow masters ,Edelbrock air gap intake. timing is at 34 degrees total, Everything is as suggested by Dave and ordered through him.
This set up is not that impressive. I thought it would have more power, according to Dave it shoud run 11s in the quarter, I dont think it will! its in a 66 Valiant with a 833 4 speed and 373 gear with 28" tire. Does anything look out of place here? Thank you in advance. the cam is 570 intake and 583 exaust with a 1.6 rocker, duration @ .050" 232 intake and 236 exhaust lobe seperation is 108 and installed centerline is 104
 
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need more cam info?
Your going to need more gear and smaller diameter tire to get the revs up IMO. 1/8 mile or 1/4.
 
Need a little clarity.....when you say that the set up is not all that impressive, elaborate. What is the grind number, lift numbers don't tell the whole story, and are they before of after the 1.6 rockers?

I'll kinda go along that the combination should net you a slip some where in the 11's; though there is more to getting there than just motor, chassis needs to work, no offense but driver ability, I see you are rowing a 4 spd, that takes some ability to do it well. With 28 inch tire, I'd be tempted to run 4.11's maybe even 4.30's

Another thought, you had Dave Hughes assist you in the selection of components, have you not asked him to assist in sorting out the combination to make it work?

Get ready for the flood!!!!!!!!!!!!
 
What is the intended use for the car? Street only? Street strip? Strip Only? Garage Queen (like my car)?
 
Is it a true 10:1? Are the pistons down in the hole? Are the heads stock. More gear will help.
 
Just some basics here, the camshaft selection is the whole program to how your engine will run out.

With performance cams as the Camshaft Numbers grow, your desired power band keeps moving up the scale.

Just for an example: Mopar 340 cam power band 1,000 to 5,000 rpm
Next step: 1,500 rpm to 5,500 rpm
Next step: 2,000 rpm to 6,000 rpm
Next step: 2,500 rpm to 6,500 rpm

Up and Up the power band goes, as the cam numbers go up.
 
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You don't have near enough gear. Also, I've never seen a good set of headers for early A body cars. Ever. If they are not custom built, they are junk and I don't care whose name is on the box.

Did you degree that cam?? Or dot to dot it? That's where I'd look after I dropped a 4.30 gear in it. If you can't or won't do that, change the cam.

My second guess is you'll be lucky to be at 9:1 as I'd bet you didn't degree the cam and didn't actually measure the compression ratio. I'm not talking about doing a bunch of math you found in catalogs and online. You need to pour the heads and do a downfill on the Pistons and THEN do the math. Otherwise, you are just guessing.

You didn't say what plug you have, but pictures would be nice. What about the fuel pump you are using?

Also, I've never ever seen any cam make 1/10 of its HP under the sweet spot so just ignore that post.

If you have answers for the above, it should run 11's. Provided you can get it to hook and your clutch doesn't break the drivetrain to pieces and how well you can actually drive a stick. It's essentially a lost art.
 
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Stock stroke 340 with a 4 speed and 3.73’s?

Let’s hear the rest the of the cam specs........ but off the top of my head I’d say it’s way too big.
(none of the cams listed on their site match those lift specs, with either 1.5 or 1.6 rockers. The two smallest ones listed are close with 1.6 rockers, and those should actually work okay in that combo.......if that’s what you have)

That trans/gear combo with closed exhaust isn’t going to need/want much cam at all.

Warm up the motor, do a compression test on a couple cylinders.

5 “pumps”, and then however many it takes to max out the gauge.

Here’s one from about 25 years ago......
340+.030, trw flat tops, 9.7cr, bowl blended x heads, m1 single plane, UD solid cam, 247/255-108, 750dp, Hooker 1-3/4 headers, 70 Dart, 4 speed with 3.09 low, 4.88’s.
Best was 12-teens at LVD.
Brought it up to Napierville in Canada on a cool fall day and it dipped into the 11’s there.
Motor was about 425hp.
 
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PRH said:
Stock stroke 340 with a 4 speed and 3.73’s?

Let’s hear the rest the of the cam specs........ but off the top of my head I’d say it’s way too big.

That trans/gear combo with closed exhaust isn’t going to need/want much cam at all.

Warm up the motor, do a compression test on a couple cylinders.

5 “pumps”, and then however many it takes to max out the gauge.
Click to expand...


LOL...that's what I said. But since I'm old school there is no such thing as a cam that's too big...you just don't have enough gear.

I agree...if the OP isn't willing to stick some gear to it he is way off on cam, and my guess is he did the dot to dot and the cam is retarded to boot.
 
disco said:
Hi I would like some help with a motor Ive just done with the help of Dave Hughs, I bulit! its a 340 bored 40 over, Icon pistons,hastings rings, 10-1 compression,63cc Edlebrock Alum rpm heads 202 & 1.6, cam is 586 ex and 584 in , 1.6 Hughes alum rockers, hughes pushrods, 750 Holley track warrior carb, pro billit msd dist, Msd 6al box, Msd wires and champion plugs, Hooker pro comp long tube headers with flow masters ,Edelbrock air gap intake. timing is at 34 degrees total, Everything is as suggested by Dave and ordered through him.
This set up is not that impressive. I thought it would have more power, according to Dave it shoud run 11s in the quarter, I dont think it will! its in a 66 Valiant with a 433 4 speed and 373 gear with 28" tire. Does anything look out of place here? Thank you in advance.
Click to expand...


This is where NOT spending $500 or whatever on your $10K + build to dyno it is suddenly worth every penny. How high does it "want" to rev? Oh wait the dyno would tell you exactly what your powerband is. A good operator could tell you what to expect in the car too.

I bet that engine with I'm assuming are unported Edelbrock heads isn't making much over 400-420HP which will be fun but not near enough with out a perfect chassis and driveline for 11's. I bet you have a mid 12 ride as it sits. Let us know what you find. J.Rob
 
Frankly, I’d be surprised if it actually ran mid-12’s as it sits.
Street oriented stick cars with street friendly gears are “usually” a disappointment at the track.

If you try not to leave too hard so it doesn’t spin, it bogs.
If you leave high enough to get around the bog, it spins.
If you leave high enough and it doesn’t bog or spin, it often breaks.

If the motor has a cam that’s in the mid-240’s or bigger, it would want to be geared so it was turning close to 7k through the lights(if you were trying to optimize it for best ET’s).
 
PRH said:
Stock stroke 340 with a 4 speed and 3.73’s?
Click to expand...
His information was scattered. Below are s what you missed.
disco said:
Its a 340 bored 40 over....
———————————————————————
its in a 66 Valiant with a
(here I assume he means cubic inch displacement)
433 4 speed and 373 gear with 28" tire.
Click to expand...

The OP gave most of the required information but not the complete picture.

Cam duration @ .050 and crank stroke along with static ratio (exact) are missing. Exact model & description of piston would help a bit.
 
PRH said:
Frankly, I’d be surprised if it actually ran mid-12’s as it sits.
Street oriented stick cars with street friendly gears are “usually” a disappointment at the track.

If you try not to leave too hard so it doesn’t spin, it bogs.
If you leave high enough to get around the bog, it spins.
If you leave high enough and it doesn’t bog or spin, it often breaks.

If the motor has a cam that’s in the mid-240’s or bigger, it would want to be geared so it was turning close to 7k through the lights(if you were trying to optimize it for best ET’s).
Click to expand...
RAMM said:
This is where NOT spending $500 or whatever on your $10K + build to dyno it is suddenly worth every penny. How high does it "want" to rev? Oh wait the dyno would tell you exactly what your powerband is. A good operator could tell you what to expect in the car too.

I bet that engine with I'm assuming are unported Edelbrock heads isn't making much over 400-420HP which will be fun but not near enough with out a perfect chassis and driveline for 11's. I bet you have a mid 12 ride as it sits. Let us know what you find. J.Rob
Click to expand...

True true and more true on the above.

That and the drivetrain/line + chassis mention from above. Running 11’s isn’t exactly an easy feat. It takes time to sort everything out and get the car and yourself right.

Looking forward to (the OP) your response.
 
ValiantRacing said:
My 318 runs 11s with a lot smaller cam, pump gas Edelbrock heads, 11s with a 340 is no problem.
Click to expand...

Does it have a stock Mopar 4 speed trans and 3.73 gears?

25 or so years ago I had a 10.5:1 340 in my 68 Satellite running 11.60’s@117........ but it didn’t have a 4 speed and 3.73 rear gears.

433 4 speed
Click to expand...

I guess we’ll have to wait for clarification....... I thought it was a typo for “833”.

If it’s an RPM headed 433 in a small car like that, and it’s set up even 1/2 way “right”, it should go 10’s.

Going quick with a stick car is mostly about “the car”.
Making enough power with a stock stroke 340 to run 11’s in a 66 valiant is absolutely “no problemo”.
It’s the stick that throws the wrench in the works.
If it’s a “race car”, it’s easier....... you buy all the good stuff so you can leave at 5 or 6k and not worry about it.
It’s a very tiny fraction of the stick shift street/strip combos that have the good stuff between the crank flange and the axle flange.
On my buddies stick shift Stocker....... that stuff costs way more than his motor does.
 
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I didn’t see 433 as a trans! But it sure can be that now can’t it. More fodder for the brain trust! LMAO! Absolutely correct! What is it that we’re dealing with? The original poster is nowhere to be found!

Wherefore thou @disco ?!?!?!?!

OK, that was rough since he posted at 8:10 am and he is probably at work waiting to get out and back home. I’ll just have to sit back with a beer and wait.....

:popcorn:

(Sorry, we have no beer icon!)
 
Wow I Hope I get some of the answers for you here and thank you very much for the help!! I have to find the cam card, but that is with the 1.6 rockers, the pistons are icon forged and Hughes did the math on the 10-1 compression, the tranny is 833, I didn't degree the cam , it's dot to dot, Dave says I'm all in at 5400 rpm, I will get the cam card and get back this weekend
 
George Jets said:
Just some basics here, the camshaft selection is the whole program to how your engine will run out.

With performance cams as the Camshaft Numbers grow, your desired power band keeps moving up the scale.

Just for an example: Mopar 340 cam power band 1,000 to 5,000 rpm
Next step: 1,500 rpm to 5,500 rpm
Next step: 2,000 rpm to 6,000 rpm
Next step: 2,500 rpm to 6,500 rpm

Up and Up the power band goes, as the cam numbers go up.
Click to expand...
1500 - 5500
 
yellow rose said:
You don't have near enough gear. Also, I've never seen a good set of headers for early A body cars. Ever. If they are not custom built, they are junk and I don't care whose name is on the box.

Did you degree that cam?? Or dot to dot it? That's where I'd look after I dropped a 4.30 gear in it. If you can't or won't do that, change the cam.

My second guess is you'll be lucky to be at 9:1 as I'd bet you didn't degree the cam and didn't actually measure the compression ratio. I'm not talking about doing a bunch of math you found in catalogs and online. You need to pour the heads and do a downfill on the Pistons and THEN do the math. Otherwise, you are just guessing.

You didn't say what plug you have, but pictures would be nice. What about the fuel pump you are using?

Also, I've never ever seen any cam make 1/10 of its HP under the sweet spot so just ignore that post.

If you have answers for the above, it should run 11's. Provided you can get it to hook and your clutch doesn't break the drivetrain to pieces and how well you can actually drive a stick. It's essentially a lost art.
Click to expand...
I'm not going to say I know the math, that's the reason I was told to talk to Dave Hughes, I gave him all he needed as far as car weight my weight tire gear trans, and ordered all parts from him, not saying he's wrong! I just don't know if I went wrong somewhere
 
RAMM said:
This is where NOT spending $500 or whatever on your $10K + build to dyno it is suddenly worth every penny. How high does it "want" to rev? Oh wait the dyno would tell you exactly what your powerband is. A good operator could tell you what to expect in the car too.

I bet that engine with I'm assuming are unported Edelbrock heads isn't making much over 400-420HP which will be fun but not near enough with out a perfect chassis and driveline for 11's. I bet you have a mid 12 ride as it sits. Let us know what you find. J.Rob
Click to expand...
I did try to get the local guy to Dyno the car for me and he told me he only likes doing mustang so I left
 
JBurch said:
Need a little clarity.....when you say that the set up is not all that impressive, elaborate. What is the grind number, lift numbers don't tell the whole story, and are they before of after the 1.6 rockers?

I'll kinda go along that the combination should net you a slip some where in the 11's; though there is more to getting there than just motor, chassis needs to work, no offense but driver ability, I see you are rowing a 4 spd, that takes some ability to do it well. With 28 inch tire, I'd be tempted to run 4.11's maybe even 4.30's

Another thought, you had Dave Hughes assist you in the selection of components, have you not asked him to assist in sorting out the combination to make it work?

Get ready for the flood!!!!!!!!!!!!
Click to expand...
 
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