Chrysler small block 416 stroker kit

Engines, Shafts, Steering, Struts, Rudders, etc.
Fastjeff
Site Admin
Posts: 1521
Joined: Sat Jul 12, 2014 5:06 am
Location: Rock Halll, MD

Re: Chrysler small block 416 stroker kit

Post by Fastjeff »

..."One guy couldn't win a football game by himself,"

No, but "Megatron" comes close!

Agreed on the larger engine--propped properly--can get better gas mileage than a smaller one, especially if the boat is underpowered.

Jeff
"We live at the bottom of an ocean of air, not at the top." General Marvage Slatington
ericinga
Aluminum Star
Posts: 170
Joined: Mon Jul 14, 2014 11:21 am
Location: Cumming, GA

Re: Chrysler small block 416 stroker kit

Post by ericinga »

Joe-
Agree with your point about volumetric efficiency.  A smaller engine that is not balanced e.g. intake flow, exhaust flow and low compression,  will not run efficiently.  A well balanced large engine e.g. intake and exhaust flow is equal, will run more efficiently.

The 318 is a poorly balanced engine that does not take advantage of it’s mechanical efficiency.  It is a mechanically balanced engine in the bore e.g. stroke and bore are almost equivalent.  However, it loses power due to low compression, poorly ported heads and intake manifold.  This is the reason so much additional power can be created by simply changing the heads and intake manifold geometry.  After these changes, the modified engine will be more efficient.  The fuel atomization will be better and combustion will be more efficient due to higher pressure.

The magic is in the balance of flow volume, power (compression) and mechanical efficiency.  The 318 makes a solid platform for 300+ horsepower with fuel efficiency.
Eric Spies
1989 32 SDFB
Twin 318s
Lake Lanier, GA
Marinette Boat
Fastjeff
Site Admin
Posts: 1521
Joined: Sat Jul 12, 2014 5:06 am
Location: Rock Halll, MD

Re: Chrysler small block 416 stroker kit

Post by Fastjeff »

...."
The 318 is a poorly balanced engine "

Millions of satisfied auto owners might not agree.

Jeff
"We live at the bottom of an ocean of air, not at the top." General Marvage Slatington
Cabinfever
Tin star
Posts: 27
Joined: Mon Jul 14, 2014 5:57 pm

Re: Chrysler small block 416 stroker kit

Post by Cabinfever »

Fastjeff wrote:...."
The 318 is a poorly balanced engine "

Millions of satisfied auto owners might not agree.

Jeff
Anything can be made better, some were made better. That being said,......... the only person who would not agree is that dude still driving around that stock Diplomat he bought off the showroom floor in 1980 with a 318, :roll: :roll: :roll: .......... with 300,000 miles on it. Then there's the guy who bought the Cuda in 1970, with the 440 six pack 8-) 8-) 8-), yea I'm the Cuda guy. :) :) :) Your right though, it is hard to beat the reliability of a Chrysler engine.
Joe
1977 28 Express
Single 318
(RESTORATION IS ALL THE ROUTINE MATIANANCE AT ONCE)
Fastjeff
Site Admin
Posts: 1521
Joined: Sat Jul 12, 2014 5:06 am
Location: Rock Halll, MD

Re: Chrysler small block 416 stroker kit

Post by Fastjeff »

Right on. A larger engine--with the proper prop (more pitch)--will give better gas mileage at cruising speed. Seen this many times (in comparative boat tests with different engine options) I don't doubt it. At WOT throttle, of course, the larger engine eats more fuel, but that is not the normal mode of boat operation, especially with a Marinette.

A bit of data to back this up: My FloScan tells me that it takes about 2 GPH for a 360 to run at 2,500 rpms--in neutral! It takes considerately more gas to turn 3,500 rpms, again in neutral. So, propping the motor to turn only 2,500 for cruising (vs. 3,500) saves gas from this factor alone. Of course, the motors can't be lugging at this rpm or all bets are off. Since the butterflies on the carbs of my 32 footer are barely open enough to admit a pencil at this speed, this is not the case in THIS instance.

Jeff
"We live at the bottom of an ocean of air, not at the top." General Marvage Slatington
Trowerpower
Aluminum Star
Posts: 174
Joined: Sun Dec 07, 2014 8:50 pm
Location: Northern Kentucky

Re: Chrysler small block 416 stroker kit

Post by Trowerpower »

Rebuilt my 318's (well i let the experts do it) with Scat Enterprises 392 strokers under your approach. 80 hours all is well. Burns the same amount of fuel at 3,000rpm but way more torque so it picked up speed. Installed roller rockers as well. Larger carbs were needed 750 cfm's. Custom cams, increases lift and duration a bit maintained 9 to 1 compression. They run great! Builder says 350 hp each. Stock props 16 x 15, 1x 1.52 transmissions. Machinist says 318's are easy to stroke because there were no clearance issues.
Trower Power
1987 32ft Marinette Sedan Flybridge
Blue Sky
twin 392 Chrysler Stroker Motors
Performance Distributors
750 Edlebrocks
fresh water cooled
1.5 to 1 velva-drives
Onan 6.5kw gen set
Fastjeff
Site Admin
Posts: 1521
Joined: Sat Jul 12, 2014 5:06 am
Location: Rock Halll, MD

Re: Chrysler small block 416 stroker kit

Post by Fastjeff »

Okay, now you need way more pitch on those props. That will give you more mpg without hindering the way she jumps onto plane.

Jeff
"We live at the bottom of an ocean of air, not at the top." General Marvage Slatington
Trowerpower
Aluminum Star
Posts: 174
Joined: Sun Dec 07, 2014 8:50 pm
Location: Northern Kentucky

Re: Chrysler small block 416 stroker kit

Post by Trowerpower »

Hey Jeff! The next time she comes out for bottom paint, i will look into different props. Will be de-winterizing on March 25th. Come on spring and not spring snow storms.
Trower Power
1987 32ft Marinette Sedan Flybridge
Blue Sky
twin 392 Chrysler Stroker Motors
Performance Distributors
750 Edlebrocks
fresh water cooled
1.5 to 1 velva-drives
Onan 6.5kw gen set
Tranquilo
Royal Aluminum Star
Posts: 245
Joined: Mon Sep 08, 2014 8:55 am

Re: Chrysler small block 416 stroker kit

Post by Tranquilo »

Why did it require the larger carb if it uses the same amount of fuel? Or is that for full throttle?
2x 1973 28 Express - Single 318
New electrical panels, water system and velvet drive
Miami FL & Catawba OH
Trowerpower
Aluminum Star
Posts: 174
Joined: Sun Dec 07, 2014 8:50 pm
Location: Northern Kentucky

Re: Chrysler small block 416 stroker kit

Post by Trowerpower »

Well i did not check my flowscan meters at wot. Spring is coming. At 3000rpm it was at 19gph.
I will right down all the numbers and post soon.
Trower Power
1987 32ft Marinette Sedan Flybridge
Blue Sky
twin 392 Chrysler Stroker Motors
Performance Distributors
750 Edlebrocks
fresh water cooled
1.5 to 1 velva-drives
Onan 6.5kw gen set
Post Reply