340 cam suggestions needed

340 cam suggestions needed - 09/16/10 03:05 AM

Guys wanting to put a cam in this 69 340 .030 over, nothing really too radical ,but have a nice lope to it and still make good power and no ping factor!.. it will be close to 10 -10.5 "1 comp TTI Headers 22-2400 stall, 3.55 gears in back , 650-750 holley vac secondary eventually. Has a edelbrock on it now, stock intake. What do u guys suggest? we only have a couple of days to get one picked out!..

Thank you~!

Posted By: scratchnfotraction

Re: 340 cam suggestions needed - 09/16/10 03:10 AM

a whiplash from hughes
check the cuda on thier web page for the whiplash

nuff said

lews car is awsome

Posted By: menomoniemopars

Re: 340 cam suggestions needed - 09/16/10 03:25 AM

That sounds tough! but it says there made more for low comp engines, this one is going to be 10 or better..

Posted By: Dave_J

Re: 340 cam suggestions needed - 09/16/10 04:01 AM

Comp Cams Extreme XE268H should make it lope a bit. Or step up one more to the XE284H but this may be too much for your stall and rear gears...

If you want a nice choppy idel look here: http://www.compperformancegroupstores.co...ry_Code=THMCRS2 .

Posted By: 73swinger

Re: 340 cam suggestions needed - 09/16/10 04:15 AM

From info given I would use this Hughes Hydraulic

http://www.hughesengines.com/Index/produ...mp;partid=21848

But if you plan to start racing it, then you will be going to steeper gears and want this one, wich I think will still be OK with the 3:55 gears

http://www.hughesengines.com/Index/produ...mp;partid=21848

Just be aware theese cams need good springs and valvetrain if you run it hard.

Posted By: patrick

Re: 340 cam suggestions needed - 09/16/10 02:27 PM

comp XE268 or lunati voodoo 60403

Posted By: Mr. T

Re: 340 cam suggestions needed - 09/16/10 04:08 PM

http://www.jegs.com/i/Mopar-Performance/312/P4120231/10002/-1?parentProductId=746961

With the combination he already has, I think this would be a good candidate. I used to have this in a mild 360, nice lopey idle and pulled good too.

Posted By: menomoniemopars

Re: 340 cam suggestions needed - 09/16/10 05:07 PM

Thanks!Were thinking about this one too... seems very close to the old street hemi grind..

http://www.monicattichrysler.com/comersus/store/comersus_viewItem.asp?idProduct=428#

Posted By: tampacuda69

Re: 340 cam suggestions needed - 09/16/10 10:34 PM

Another vote for Comp XE268.It will do everything you're looking for. I have this same combo you describe except 3:23 Sure Grip and 10.2:1CR.with an Air Gap Intake. It is perfect with your convertor and gears.
Steve Dulcich made 392HP with this combo. It's a proven combination.

Posted By: RobX4406

Re: 340 cam suggestions needed - 09/17/10 01:11 AM

Which edelbrock intake and what stock manifold are you swapping out? Performer 318/360 is a junk manifold. A stock Iron 340 intake is better, especially if you put a 1" spacer on it

A 2.02 valve headed 340 with a xe268H will make about 350hp with everything right. 340's will really have something along the lines of 9.5-9.7:1 even using higher compression 68-71 pistons.

I'd like to see that Dyno Derby 395hp, 340, run on the dyno at Indio Motor. No chance it makes 395.

Just as a side note. I've seen at least 6 engines, 340-360, all built with the same basic package, 9.5-10.5:1, stock heads good valve job, xe268H, air gap/LD340, 670-950 carbs, headers and none of them made more than 360hp, most made between 335-350hp. The ones that ran at the track all MPH'd like a 330-350hp engine per weight.

The XE268H is a good all around camshaft.

Posted By: menomoniemopars

Re: 340 cam suggestions needed - 09/22/10 02:58 AM

Quote:

Which edelbrock intake and what stock manifold are you swapping out? Performer 318/360 is a junk manifold. A stock Iron 340 intake is better, especially if you put a 1" spacer on it

A 2.02 valve headed 340 with a xe268H will make about 350hp with everything right. 340's will really have something along the lines of 9.5-9.7:1 even using higher compression 68-71 pistons.

I'd like to see that Dyno Derby 395hp, 340, run on the dyno at Indio Motor. No chance it makes 395.

Just as a side note. I've seen at least 6 engines, 340-360, all built with the same basic package, 9.5-10.5:1, stock heads good valve job, xe268H, air gap/LD340, 670-950 carbs, headers and none of them made more than 360hp, most made between 335-350hp. The ones that ran at the track all MPH'd like a 330-350hp engine per weight.

The XE268H is a good all around camshaft.

It has a edelbrock carb and stock 340 intake. want to get a 340 avs carb instead a 1" open spacer? well we went with the 4452992 cam and a 11" 2400 stall.is that enough stall with 3.55's? this is not a race car just a nice cruiser . so it won't even be at 10.1 then? so set that cam at 106 then instead of 108? were thinking 108 cause of comp but if it isn't that high then we will set it at 106 for more bottom end.

Posted By: 451Mopar

Re: 340 cam suggestions needed - 09/22/10 04:34 AM

Could you post some more info:
How are you calculating 10 to 10.5:1 compression?
What pistons? flat tops, or stepped for quench?
What mods have been done to the heads?
What size tires to help figure cruse RPM?
What vehicle or vehicle weight?
What performance goals?
How low of octane fuel is going to be used?
What altitude will the vehicle be driven?
How often will it be driven?
Does the cam have to work with stock stamped rocker arms?
If aftermarket rocker arms, what ratio?

From your initial post it looks like the car is setup for street driving. The gear/converter/intake/carb seem to be OK for a mild performance, but the compression might be an issue. At least it is on the high side. It is easier to remove some chamber volume or piston material or use a thicker head gasket to lower compression then to add material or reduce gasket thickness to increase compression.
Most off the shelf cams usually expect less compression with a better intake system. You might want to call a cam grinder and see if they recommend a custom ground cam with extra intake duration and a wider LSA, or change the installed centerline to retard the cam?

Posted By: menomoniemopars

Re: 340 cam suggestions needed - 09/22/10 01:11 PM

Quote:

Could you post some more info:
How are you calculating 10 to 10.5:1 compression?
What pistons? flat tops, or stepped for quench?
What mods have been done to the heads?
What size tires to help figure cruse RPM?
What vehicle or vehicle weight?
What performance goals?
How low of octane fuel is going to be used?
What altitude will the vehicle be driven?
How often will it be driven?
Does the cam have to work with stock stamped rocker arms?
If aftermarket rocker arms, what ratio?

From your initial post it looks like the car is setup for street driving. The gear/converter/intake/carb seem to be OK for a mild performance, but the compression might be an issue. At least it is on the high side. It is easier to remove some chamber volume or piston material or use a thicker head gasket to lower compression then to add material or reduce gasket thickness to increase compression.
Most off the shelf cams usually expect less compression with a better intake system. You might want to call a cam grinder and see if they recommend a custom ground cam with extra intake duration and a wider LSA, or change the installed centerline to retard the cam?

I was just going off what these engines supposedly had from the factory?
The engine builder said he would just use some 340 replacement pistons?
Nothing done to the heads just stock J heads with 2.02 1.60 valves

Not sure on tires size maybe 245 ?
Its in a 72 challenger
Its a nicely restored car that will get driven to some car shows etc, may never see the track?
Most I can get is 91 octane
DA is around 2-3000 feet most the time?
will have the stock shaft system still in place

hope this helps

Posted By: Lew

Re: 340 cam suggestions needed - 09/22/10 11:59 PM

Quote:

a whiplash from hughes
check the cuda on thier web page for the whiplash

nuff said

lews car is awsome

Just had to chime in on this. First off thanks for the compliment on the little
cuda scratch. We do not know for sure what our comp. is. We do know that a few weeks ago at a local track (1/8 mile) we twisted off an 8.17, which comes out somewhere in the 12.70's, i'm thinkin this cam works very well for the average streeter, whatta ya think?

Posted By: 451Mopar

Re: 340 cam suggestions needed - 09/23/10 06:35 AM

I am trying to figure what pistons you have, so a few more questions?
Do you know the piston manufacturer name?
How many valve reliefs 2 or 4?
Are they Cast, Hypereutectic, or Forged?
At TDC does the is the top of the piston above or below the block deck? and by how much?

To figure true compression ratio, do you know what the measured cylinder head volume is?

And last one, which head gaskets are you using?

Here is why it matters, your compression ratio could be as high (or higher) than 10.85:1.
The 10.85:1 number assumes using the Keith Black #243 piston, a 65cc cylinder head volume and a 0.020" thick head gasket.
On the low side, the compression could be 7.95:1 using the Speed Pro ZL2385 piston, a 72cc head volume, and a 0.040" head gasket.

From looking at Summit racings prices, it looks like the most affordable piston would be the Federal Mogal Z428P30 piston at $31.69 each?
This is a cast piston with 4 valve reliefs, and should sit 0.007" above the blocks deck.
The description did not have the valve relief volume listed, but from the other pistons with 4-valve reliefs it should be about 7cc?
So this piston with the theoretical 65cc head, and 0.020" gasket should give you 10.41:1 compression.
Just switching to a 0.040" head gasket will drop the compression to 9.88:1 compression.

Cams:
Hughes Whiplash HMC2336AL 223/236 @ 0.050", 0.512"/0.518", 107 LSA.
Hughes HEH2328AL 223/228 @ 0.050", 0.506"/0.524", 111 LSA.
Hughes HEH2832AL 228/232 @ 0.050", 0.524"/0.540", 110 LSA.
Lunati Voodoo #60403 268/276 Advertised, 226/234 @ 0.050", 0.494"/0.513" 110 LSA.
Comp Cams XE268H 268/280 advertised, 224/230 @ 0.050", 0.477"/0.480", 110 LSA.

I think any of the above cams listed above should work decent. If you like the sound and rough idle, the whiplash would be good. The wider LSA of the HEH2328AL would give a nicer idle.
The HEH2832AL is getting big for your converter/gear, and may punch the pushrods through the stock rocker arms.
It looks like the lobe profile of the comp cam may be less agressive and might be easier on the valve train.
The Lunati cam would probbably be my choice, mainly because it looks like it might be the least expensive. It also looks like a really nice cam, at least on paper?

Posted By: Dodgem

Re: 340 cam suggestions needed - 09/23/10 11:36 AM

106 would be the normal install with a 2400 stall you are going to want to install it at 102 or it will be flat as a heck till 3300 rpm??

Posted By: menomoniemopars

Re: 340 cam suggestions needed - 09/23/10 12:42 PM

Quote:

I am trying to figure what pistons you have, so a few more questions?
Do you know the piston manufacturer name?
How many valve reliefs 2 or 4?
Are they Cast, Hypereutectic, or Forged?
At TDC does the is the top of the piston above or below the block deck? and by how much?

To figure true compression ratio, do you know what the measured cylinder head volume is?

And last one, which head gaskets are you using?

Here is why it matters, your compression ratio could be as high (or higher) than 10.85:1.
The 10.85:1 number assumes using the Keith Black #243 piston, a 65cc cylinder head volume and a 0.020" thick head gasket.
On the low side, the compression could be 7.95:1 using the Speed Pro ZL2385 piston, a 72cc head volume, and a 0.040" head gasket.

From looking at Summit racings prices, it looks like the most affordable piston would be the Federal Mogal Z428P30 piston at $31.69 each?
This is a cast piston with 4 valve reliefs, and should sit 0.007" above the blocks deck.
The description did not have the valve relief volume listed, but from the other pistons with 4-valve reliefs it should be about 7cc?
So this piston with the theoretical 65cc head, and 0.020" gasket should give you 10.41:1 compression.
Just switching to a 0.040" head gasket will drop the compression to 9.88:1 compression.

Cams:
Hughes Whiplash HMC2336AL 223/236 @ 0.050", 0.512"/0.518", 107 LSA.
Hughes HEH2328AL 223/228 @ 0.050", 0.506"/0.524", 111 LSA.
Hughes HEH2832AL 228/232 @ 0.050", 0.524"/0.540", 110 LSA.
Lunati Voodoo #60403 268/276 Advertised, 226/234 @ 0.050", 0.494"/0.513" 110 LSA.
Comp Cams XE268H 268/280 advertised, 224/230 @ 0.050", 0.477"/0.480", 110 LSA.

I think any of the above cams listed above should work decent. If you like the sound and rough idle, the whiplash would be good. The wider LSA of the HEH2328AL would give a nicer idle.
The HEH2832AL is getting big for your converter/gear, and may punch the pushrods through the stock rocker arms.
It looks like the lobe profile of the comp cam may be less agressive and might be easier on the valve train.
The Lunati cam would probbably be my choice, mainly because it looks like it might be the least expensive. It also looks like a really nice cam, at least on paper?

At this Time I don't know what piston he is using brand etc?.. Going to try and find out. also I told him to CC the J head just to see where its at. The thing with the cam we Already have the 4452992 cam ,bought it last week. So that is the cam we have to work with. So I guess until i get more info from the builder we will have to figure out the best ICL and not make a ping motor! I thought 106, but now I see someone says 102? Man this thing won't even idle very well at 102 will it? I totally appreciate u working with me on this and welcome your help as we go along here!.Also When he bought this car he thought he was getting a nice restored car! well the motor was junk, trans junk, needed a dash harness!. The guy obviously lied to just sell it and it was not a cheap car either! if u would have seen the car u would have thought there was nothing wrong! everything painted nice and clean etc! I just want my brother to be happy and not have any problems with this new build!
One other thing this is my older brother's car and I am helping him the best I can AS i know pontiacs not mopar, so that is I why appreciate all help from everyone here!

Posted By: 451Mopar

Re: 340 cam suggestions needed - 09/23/10 03:41 PM

Quote:

At this Time I don't know what piston he is using brand etc?.. Going to try and find out. also I told him to CC the J head just to see where its at. The thing with the cam we Already have the 4452992 cam ,bought it last week. So that is the cam we have to work with. So I guess until i get more info from the builder we will have to figure out the best ICL and not make a ping motor! I thought 106, but now I see someone says 102? Man this thing won't even idle very well at 102 will it? I totally appreciate u working with me on this and welcome your help as we go along here!.Also When he bought this car he thought he was getting a nice restored car! well the motor was junk, trans junk, needed a dash harness!. The guy obviously lied to just sell it and it was not a cheap car either! if u would have seen the car u would have thought there was nothing wrong! everything painted nice and clean etc! I just want my brother to be happy and not have any problems with this new build!
One other thing this is my older brother's car and I am helping him the best I can AS i know pontiacs not mopar, so that is I why appreciate all help from everyone here!

The P4452992 cam is a 280/280 advertised, 0.474"/0.474", 110 LSA cam. I think you may end up with about 10:1 compression? So installing the cam at 106 would be OK. If the actual compression is closer to 9.5:1 then you should advance the cam a bit. Anyhow, it should be close. This cam should work, but is a bit big for your combination of converter/gear. I am not sure what your comment on idle was supposed to mean? It should idle OK, but should sound like it has some cam in it. Since you already have the parts, I'd use them, and then work on getting it well tuned.

Posted By: Dodgem

Re: 340 cam suggestions needed - 09/23/10 04:33 PM

My mistake 104 install would be fine 106 if you have a 3000 stall

Posted By: YO7_A66

Re: 340 cam suggestions needed - 09/23/10 04:52 PM

Dogem,

Is there a guideline to what degree the cam is put in at versus the converter stall?

Thanks

Posted By: menomoniemopars

Re: 340 cam suggestions needed - 09/23/10 04:59 PM

Yea That is what I told the builder was to keep it at 10.1 nothing more. So 106 will be good? if we went to 104 could be too much closing the valve earlier yet?.. What I meant is if i go to 102 from the other comment, doesn't the idle get choppier being a earlier ICL or no?.. I plan on doing the dist mod also.. thinking this cam will like about 15-18 initial? Being a street car it shouldn't be a dog even with the his current gear, and the 11" 2400 conv right?He wants to be able to have a nice power band and not be a pig til it comes up on the cam when he tries to goose it.. thanks guys! Really appreciate it!

Posted By: 73swinger

Re: 340 cam suggestions needed - 09/23/10 07:40 PM

Keep at it Darby, It will run well. The distributor mod is a must, 15-18 initial 34/35 total should be in the ball park. With the availabe replacement pistons, I think your compression will be closer to 9-91/2:1
allthough I have Aluminum heads, I used a thinner head gasket to get compression at 10:1 the block was also deck quite a bit. I have often used the 87 octane to top off the tank after racing and street drive my junk with no ping. The only time I got pinging was before limiting advance.
Good luck, see you this weekend??

Posted By: menomoniemopars

Re: 340 cam suggestions needed - 09/23/10 10:24 PM

Quote:

Keep at it Darby, It will run well. The distributor mod is a must, 15-18 initial 34/35 total should be in the ball park. With the availabe replacement pistons, I think your compression will be closer to 9-91/2:1
allthough I have Aluminum heads, I used a thinner head gasket to get compression at 10:1 the block was also deck quite a bit. I have often used the 87 octane to top off the tank after racing and street drive my junk with no ping. The only time I got pinging was before limiting advance.
Good luck, see you this weekend??

How did u know it was me Chris? lol.
Yes I plan on being there sunday.. did some rear suspension mods.. hoping for some traction and 11.60's!..

Posted By: menomoniemopars

Re: 340 cam suggestions needed - 10/14/10 07:15 PM

Well according to the dyno today it made 376 hp @ 6000! and 377 torque at 4500....

Posted By: 73swinger

Re: 340 cam suggestions needed - 10/14/10 10:27 PM

Nice numbers for a mild build.

Posted By: RobX4406

Re: 340 cam suggestions needed - 10/14/10 10:31 PM

Nice numbers.

That 280/474 cam is not a really small stick from a Dur at .050. It's in the 238 range IIRC.

Posted By: menomoniemopars

Re: 340 cam suggestions needed - 10/15/10 01:33 AM

Quote:

Nice numbers.

That 280/474 cam is not a really small stick from a Dur at .050. It's in the 238 range IIRC.

thanks yes u are correct it is 238 @.050.. it will need the dizzy worked on tho as it was idling at 1100 my brother said , but making 12" of vac! once i give it more int it will be even snappier, that was at 34 total and his crappy old headers it will be using the TTI stepped headers he bought for it also..

Chris
He is happy thats for sure! see ya saturday man! I got new tires in back and new QA1's Up front now! Hope to get warned for having no roll bar!

Posted By: forphorty

Re: 340 cam suggestions needed - 10/15/10 06:18 PM

Souds like it's gonna run good for you. It's gonna want more than 2400 stall tho.

Posted By: menomoniemopars

Re: 340 cam suggestions needed - 10/15/10 07:19 PM

Well according to my brother it was making 350 ftlbs at 3000, so i think it may be ok.. This is just a nice cruiser , doubt it will see the track by him