Cam help with 340 "super bee 3"

[dwade2777]

Hi my Name is Damon and Im new to the forum. Picked up a 1972 18' Sutphen With a Chrysler 340 and a 270 Volvo penta out drive.
Previous owner added some parts that were not stock. Trying to figure out what came shaft I should order and where to order from??
What the boat has: Stock exhaust manifolds, two Holley 650cfm carbs on top of an Eldebrock street tunnel ram! Crane hydrolic roller rockers and the rest is stock.
I want to use the Tunnel ram cause it looks cool but change the 650 carbs for two 390cfm carbs. I don't know what the rpm is for WOT for the 340 so picking and finding a cam for this set up has left me confused. Also not sure what rpm's the 270 Volvo penta can handle.

Any help would be great!

 

[daves69]

Maybe some spec sheets can help.

Confirm the rotation (std / rev)

"Crane hydrolic roller rockers"
Are they 1.5 or 1.6 ratio rockers?

"and the rest is stock"
Try to get all of the "changed" parts identified with part numbers and make a list.

 

[bondo]

Hi my Name is Damon and Im new to the forum. Picked up a 1972 18' Sutphen With a Chrysler 340 and a 270 Volvo penta out drive.
Previous owner added some parts that were not stock. Trying to figure out what came shaft I should order and where to order from??
What the boat has: Stock exhaust manifolds, two Holley 650cfm carbs on top of an Eldebrock street tunnel ram! Crane hydrolic roller rockers and the rest is stock.
I want to use the Tunnel ram cause it looks cool but change the 650 carbs for two 390cfm carbs. I don't know what the rpm is for WOT for the 340 so picking and finding a cam for this set up has left me confused. Also not sure what rpm's the 270 Volvo penta can handle.

Any help would be great!

Ayuh,..... 'n that's really gonna be a Problem,....

Big Tall Single plenum intakes don't make power til Way High Up the Rpm band,...

Boat's need serious Grunt, down Low, at just over Idle,....

Unless that boat is a feather-weight hull, you've got exactly the Wrong build goin' on with that motor,...

 

[dwade2777]

Maybe some spec sheets can help.

Confirm the rotation (std / rev)

"Crane hydrolic roller rockers"
Are they 1.5 or 1.6 ratio rockers?

"and the rest is stock"
Try to get all of the "changed" parts identified with part numbers and make a list.

Wow! thanks for the great info.
My list so far:

340 Block 4.040 bore
3.31 stroke
9.0:1 Compression
Forged crank (stock)
Right hand rotation ( standard )
No camshaft came with the engine ?
Can't find part number on hydraulic rolling rocker. It's adjustable and is orange redish. I think Crane cam?
Crane Pushrods part number 69690-2
Possible cam used but can't confirm Direct Connection P4120653. 284 duration, 60 overlap, .528 lift
Edelbrock street tunnel ram built for 340 mopar P7120 Quads
two Holley 650cfm carbs. Edelbrock recommends two Holley 450cfm. I've read two Holley 390cfm carbs would work well?

 

[dwade2777]

Wow! thanks for the great info.
My list so far:

340 Block 4.040 bore
3.31 stroke
9.0:1 Compression
Forged crank (stock)
Right hand rotation ( standard )
No camshaft came with the engine ?
Can't find part number on hydraulic rolling rocker. It's adjustable and is orange redish. I think Crane cam?
Crane Pushrods part number 69690-2
Possible cam used but can't confirm Direct Connection P4120653. 284 duration, 60 overlap, .528 lift
Edelbrock street tunnel ram built for 340 mopar P7120 Quads
two Holley 650cfm carbs. Edelbrock recommends two Holley 450cfm. I've read two Holley 390cfm carbs would work well?

 

[bondo]

Wow! thanks for the great info.
My list so far:

340 Block 4.040 bore
3.31 stroke
9.0:1 Compression
Forged crank (stock)
Right hand rotation ( standard )
No camshaft came with the engine ?
Can't find part number on hydraulic rolling rocker. It's adjustable and is orange redish. I think Crane cam?
Crane Pushrods part number 69690-2
Possible cam used but can't confirm Direct Connection P4120653. 284 duration, 60 overlap, .528 lift
Edelbrock street tunnel ram built for 340 mopar P7120 Quads
two Holley 650cfm carbs. Edelbrock recommends two Holley 450cfm. I've read two Holley 390cfm carbs would work well?

Ayuh,.... Standard rotation is Left-handed,....

Rotation is observed at the Flywheel,....

 

[dwade2777]

Thanks I did not know that. Im confused. Block says one thing Engine tag says another. Engine tag says: LM340 BT LX/850. Not sure what that means? Other than Marine 340 block.

 

[fastjeff]

I can guarantee you that block never came hoped up like that!

Sounds like a really cool ride. For a cam choice I'd go to the tech service offered by your favorite cam company. Tell them what you have, and what you want it to do, and they'll select one for you.

On carb sizing, most people (ah-hem!) grossly over size the carbs they use. A LOT less carb makes about the same power with lots less trouble. Note that the NASCAR Nationwide cars make damn good power with one, 390 CFM 4 barrel carb.

Jeff

 

[daves69]

http://www.marineengine.com/manuals/chrysler/engine_id.html

"Engine tag says: LM340 BT LX/850"

The "L" in "LX" indicates left hand rotation.

"No camshaft came with the engine ?"

So the block has no cam in it?

"Can't find part number on hydraulic rolling rocker."

Most likely 1.5 (standard ratio) but you need to be sure before you purchase a cam.

A .528" lift cam spec will be at the standard 1.5 rocker ratio.
1.6 ratio will make it .563" lift.

 

[300hb]

Truck/RV cams are recommended most because of the low, low idle you'll be running
I've come across Chrysler marine cams but no one who has any idea what the specs are. Kinda like their timing... (sorry) The closest listings to what they may have been I've found were here:

http://www.itacr.com/catalogos/sealed.pdf

Shows 2 performance cams on page 9. CS-1053M & CS-1054M which maybe R.H.

Federal-Mogul Resource Center - Part Details
Part Number CS-1053M
Camshaft





Specifications


Mfg.Chrysler
EngineSmall Block
Lifter TypeHYD
Cam Lift Int..2731
Cam Lift Exh..2744
Valve Lift Int..410
Valve Lift Exh..411
Duration @ .050 Lift197/199
Duration @ .006 Lift276/283
Lobe C/L111
Overlap56
Cam SeriesMarine



Performance Applications 101
Applications


P02
Performance

 

[bondo]

Wow! thanks for the great info.
My list so far:

340 Block 4.040 bore
3.31 stroke
9.0:1 Compression
Forged crank (stock)
Right hand rotation ( standard )
No camshaft came with the engine ?
Can't find part number on hydraulic rolling rocker. It's adjustable and is orange redish. I think Crane cam?
Crane Pushrods part number 69690-2
Possible cam used but can't confirm Direct Connection P4120653. 284 duration, 60 overlap, .528 lift
Edelbrock street tunnel ram built for 340 mopar P7120 Quads
two Holley 650cfm carbs. Edelbrock recommends two Holley 450cfm. I've read two Holley 390cfm carbs would work well?

Ayuh,.... Generally speakin',.... a motor build starts with a Plan,....

All the "Parts" have to work together,...
Different parts for different reason,...
Hot-roddin' a motor is done the same way, for the Best results,...

Yer motor ain't stock, by any means, so the numbers don't help much,...
You have to figure out the Exact details to make it work, as Best as it can,...

You say it's 9:1 compression,... Have you measured, 'n Checked this to be a Fact,..??

Now for the Cam, as everybody's been pointin' ya towards a Marine/ RV/ Truck grind, which is what boat motors Need to idle low, to be able to shift the drive,...
The "Direct Connection" (whatever that is), sounds pretty darn Tall, like a hot-rod Car cam,...
If so, you'll loose the low idle needed(650/ 700 rpms), 'n you run the possibility of Reversion of water in the exhaust,...
You need to get a cam that idles smooth, 'n has a power band of idle to 'bout 5000 rpms,...

The reason yer choice of intake manifold is a Bad 1 is that it builds power in the 2500/ 6500 rpm band,...
Ya need a mid-rise intake, 'n a single 4bbl. carb for a solid Marine motor,...
The carbs, Any carbs, will be pretty much Un-tuneable at anything near idle, 'cause of poor vacuum signals,...

In order for there to be a remote chance of makin' that intake, 'n a Big cam work, the 1st thing that'll need replacin' is the Exhaust,...
Stock manifolds are a serious known Choke point,....
Ya can't pump Big air in, if it can't get Out,...

 

[daves69]

"Direct Connection" (whatever that is)"
Direct Connection was a Chrysler factory engineered parts outlet for Chrysler enthusiasts. It's now Mopar Performance.

And a favorite advertisement that would get under the competitions skin............

 

[daves69]

Damon, the 653 is the smallest mechanical cam from Mopar that require the matching lifters and adjustable rockers and pushrods.
If you decide to go to smaller hydraulic cam you'll need to change the rest.

 

[bondo]

"Direct Connection" (whatever that is)"
Direct Connection was a Chrysler factory engineered parts outlet for Chrysler enthusiasts. It's now Mopar Performance.

And a favorite advertisement that would get under the competitions skin............

Ahhh,....Thanks,... bein' a Chevy guy, I missed that memo,......

But Chrysler, or Chevy, ya gotta build a balanced package,...

 

[dwade2777]

Sorry for the delay, I ordered a cam from Racer Brown. Let him know what I had and recommended a cam from idle to 4800rpm.

I've been cleaning, prepping and rebuilding. Block, crank, heads... lots and lots of elbow grease. Will post some pics of progress.

Any one know where I can order replacement parts for a Jabsco water Pump? The robber impellor is shot.

 

[fastjeff]

This site.

Jeff

 

[dwade2777]

I looked here but could not find. Looks like ebay may be the best place? I have to pull impeller see if there's a part number on it.
The Jabsco pump number is 17200 0001

 

[300hb]

http://www.hurrikain.com/Chrysler-raw-water-pumps.htm