Ad Radar
Popular Hot Rodding
Click here to find out more!

questions on Engine Masters Fall 2010 volume 13 no 3 issue

  
Popular Hot Rodding
Item Posts    Sort Order

questions on Engine Masters Fall 2010 volume 13 no 3 issue

 
kwhooler kwhooler
New User | Posts: 5 | Joined: 11/10
Posted: 01/31/11
07:57 PM

After reading the Magnum Motivation article in Engine Masters Fall 2010 volume 13 no 3 issue, I was impressed, but what about us heavy haulers? We need the torque & horse power on the low end starting around 2500rpm
           There are a lot of “V8 Magnum” trucks in the local U-Pull-It junkyard. My 1st question is; would the 360 magnum heads increase performance? Or will it put me back to square one. I discovered that big valves on an engine built for low end torque are bad and severely hurt performance..  2nd What about 318 magnum heads, would using a set of those get the better air flow and still keep the smaller valves & hopefully get better performance / gas mileage.
         See the reason for the Question Below.

  About 15 years ago, working with an engine machine shop known for its great racing engines I built an engine for my Dodge Champion Class C 18 ft camper, they did the machine work I assembled. It started with 340 heads, factory Mopar 340 4 bbl intake and a 1200 cmf Thermo-Quad. I installed a Blue Racer Wolverine RV cam (WG – 1116 specks below) on a 360 block - bored .030 over I used forged pistons (9.1compression) and the stock crankshaft with a high volume oil pump and the oil pan baffle from the 340. Factory distributor with a AcCell Super coil.
  It couldn’t get out of its own way.    It was so noisy you couldn’t hear the radio at full volume. And I was getting between 5 – 8 MPG headed to Florida as compared to the original 318 that delivered 10 – 12MPG and it  only had 8-10 lbs oil pressure running and 5 lbs at idle on its 1 and only trip to Disney.
After a year of frustration & trial and error. The engine shop said it was a tuning issue because the same configuration was running GREAT at the strip and in 2 street machines, he was correct I road in a ‘67 Dodge Dart that would “light up” the tires, running the identical build except the cam. They loaned me a “Custom High performance Distributor, to prove their point, it was worse. 15 years ago there wasn’t a lot of online help / information. I was getting ready to change the Cam next.
I found the problem / issue, by using an engine design program (Dyno2000). I found it was caused by the big valves & 1200cmf carburetor in a 8500lb RV. Replaced the heads with the original from the 360 installed a 650 cmf Edelbrock. It ran much better & got 12 – 14 MPG. Tried a set from a 318 and it was outstanding, so I left them on and quit while I was ahead. It is probably be valve size, BUT could be the smaller head chambers or a combination of both.
With the original stock 318 it would top Summit Mt @ 52 mph running 2nd gear With the 1st motor I built it topped it @ 35 mph in 2nd gear and you couldn’t hear, even shouting at the top of your voice. The finished motor (318 heads) topped it @ 75 mph in Drive /3rd gear (probably would have gone faster but couldn’t take the last curve any faster)
I put over 150k miles on the RV running “MY” engine over a 9 year period. Then the frame went, I’m now moving the motor, transmission & rear end to a New body (Winnebago LaSharo) and will be looking to rebuild the engine in the near future. It sat parked in the back yard for 3 years.

Any input would be greatly appreciated.
Blue Racer Wolverine RV cam WG – 1116 specks
Cam lift int .280 exh .295
Valve lift int .420 exh 443
Lobe ctrs int   107 exh  117
Lash hot HYD
Adv dur int 270 exh 280
.050 dur int 204 exh 214
The Summit Mtn on Rt 40 in Hopwood Pa is 3 miles long @ 7.5% grade and gains 1230ft in elevation in the 3 miles

The 340 parts came from a neighbors 1971 Cuda, that shattered a piston and cracked the block, so I got it all for $50 in 1977.
The block came out of a 1979 Dodge truck, had to buy the truck to get the motor. $300
The Dodge Champion 18 ft camper was 6000gvw add people gas and suitcases it ended @ 8500lbs at the local scales. Got it for $2500 because of the motor and condition. I invested over $2000 in the motor as my wife continually reminded me, but , that includes the 79 Dodge Power Wagon I bought for $300  to get the engine.  

gtomustang gtomustang
Enthusiast | Posts: 457 | Joined: 06/09
Posted: 02/01/11
05:30 PM

1) It isn't so much the large valves that kill low end performance, its the bigger ports behind them that kill low speed airflow thru the engine, and the larger combustion chamber that reduces compression inside the cylinder.  Now, if you had a 4inch stroke MoparPerformance crankshaft to turn a 318 into 392 cid or a 360 into a 400+ cid, then those 360 heads would be great.

If you don't mind tearing into your old 360, stroking out to 400 would be a good idea, you'd have big block displacement but with small block weight.  Design the engine around lo-RPM, and the mileage wouldn't be as bad as say a big block with 3.73 or so rear gears.

2) that carb as you know is wayyyyy too much for your engine.  Luckily it wasn't a 1970 360, the ports in the heads are pretty close to a 340.  It sounds like the shop has no clue how to build anything besides an all-out race car.  Not unusual, unfortunately...a company finds one recipe, and tries to make all customers fit it.

You're lucky about that 1979 block, however...Mopar was going out of biz then, the nickel content in the block is pretty low to save on manufacturing costs.

3) too bad a mopar overdrive automatic trans won't fit well, it may be too fat to fit your trans tunnel...then again, its a motorhome, not a truck/van body front, right?  Then still again, i think the mope trans needs a computer.  The A999 trans is a 904 torqueflite, but it has a steeper first gear, which would allow you to pull off the line better yet still run close to highway gears in the rear and get decent mileage at highway speeds.  i think there was a 3 speed auto from the 90's that was a 727 copy but had a deeper first gear, as well. but you may find that shifting from first to second the engine feels like it falls out of its power band except for at full throttle shift.

you can get a kit to put in a GM TH700R4 or TH200R4, but when you pull into a mopar dealer for repairs on the road, they are gonna wonder WTF. Confused  
Just because you can't do it...doesn't mean its impossible

3836bbl 3836bbl
Enthusiast | Posts: 407 | Joined: 11/10
Posted: 02/02/11
03:25 PM

kwhoowler welcome to the forum. The Magnum 5.2ltr/318ci or 5.9ltr/360ci heads will flow beter than most of the pre-92 340/360ci LA style heads BUT the magnum engine valvetrain is completely differant from the pre-92 LA style that have rockershaft & oil thru them, The magnums oil thru the lifter & pushrods & have 1.6-1 ratio pedistal mounted rockers, the heads will bolt on you need the hollow pushrods, Magnum Rockers, proper lifters, Magnum style intake manifold they bolt down verticaly (there are aftermarket 4bbl aluminum intakes available from a few differant MFGS), insted of bolting down horizontaly like the LA 273-318-340-360ci engines. There are other differances in the blocks & front covers. Just do your research before you purchase any parts. There is a good place to get some info. on the Magnum head swap www.moparts.com/tech look for the magnum head coversion in the small block section of the index. If you have any other questions just ask. There are a couple of good Mopar forums, Mopar Muscle Mag. Forum , www.forBbodiesonly.com , www.moparts.com , Good luck, happy Moparing.  3836bbl/Budnicks  
"Fill Your Library Before Your Fill Your Garage"  3836bbl alias Budnicks

kwhooler kwhooler
New User | Posts: 5 | Joined: 11/10
Posted: 02/02/11
09:24 PM

To GTOMUSTANG
. The LeSharo is a front wheel drive RV, powered by a 75hp 4 cylinder Renault Diesel. The motor was frozen (cracked block) witch is how I picked it up really cheep, making it within my budget to do, and it starts out weighing 1500lbs less and is more aerodynamic than my old Dodge Champion There's a "little" work to stuff everything in. Sooo--- Size doesn’t matter (Ha Ha) I’m making everything to fit anyway so I’m going to invest in a (1989 – 1991) Dodge 518, it has the same gear ratio as the 727 I’ve been running, but with a 31% overdrive, I think it will pay for itself with the gas mileage increase over the Dodge 727 There is a 4 part kit ($98.00) to do away with the Computer and still keep everything automatic, it switches on oil pressure and engine vacuum.

  Going with the 4in stroke crankshaft  just isn’t in the budget right now.

If I’m reading you correctly why is the low nickel content of the 1979 block better?

  When they see this thing they are going to be saying WTF   Confused  anyway!!! I doubt any other mechanic will ever work on my “WeeBeastie”.  The kids named it, our old RV was the “Beast” because not many factory cars or trucks and NO campers ever passed or even kept up with us in the mountains.

      TO 3836BBL

.    I’ll checkout the website just for more knowledge. After all, knowledge is the one thing you can never get enough of. BUT From reading this it sounds easer to just get a Magnum 360 block & put Magnum 318 heads on it & run an RV cam. Then I could go with an EFI throttle body or maybe a multiport fuel injection as the next step, IF I could do so with minimum the amount of computer input like the Holley Stealth Ram.
   It’s just a dream, because just like the 4in stroker crank it just isn’t the budget nor is it practical, so it looks like I’ll stay with what I have. It took me 2 years of measuring and planning to start this project and then 2 years to find a LeSharo in good shape that I could afford. You never know what’s in the future.
  After all a boost from 75hp to 300hp should be enough of an increase.
 Just a side note it has a transfer case attached to the Dodge 518 transmission out of a (Power Wagon) and will have a Dana 70 under the back with a Dana 44 in the front.
  I have always wanted a 4x4 RV but couldn’t afford one till now
  Thank you both for the help and advice  

gtomustang gtomustang
Enthusiast | Posts: 457 | Joined: 06/09
Posted: 02/03/11
06:16 AM

well, its generally better to have a higher nickel content--tho when you bore the cylinders, the machine shop won't agree Smile lol--b/c it makes the block stronger. not that you're gonna rev this sucker, but I was thinking in terms of standing up to detonation when towing a full load up an incline. but I probably phrased that in a confusing way.

now, did I read that right myself, you're turning a front wheel drive to a rear wheel drive? that's some work to get the drivetrain phased correctly so no vibrations when the rear axle moves up and down and side to side in a corner, but if you can do that, then putting in a 518 is a piece of cake   and yes, that trans will go a long way to help you. it will help the fuel economy, but also should help the engine run lower RPMs, which is less stress and longer life. so you get your money back that way, too.  
Just because you can't do it...doesn't mean its impossible

kwhooler kwhooler
New User | Posts: 5 | Joined: 11/10
Posted: 02/03/11
02:36 PM

Yes, I started out converting a front wheel drive to a rear wheel drive then decided to go for broke and go to 4WD I was buying the 518 anyway so I just picked one from a 4WD Power Wagon adding the transfer case was only $100 more than the transmission alone. I went with the Dana 70 duallie rear with single rims as a way to get the tires to match the same width as the original rear tag axel; it ends up only ½” wider. Running duals would require 6” fender flairs, and I didn’t think it would look right. I’m installing a split drive shaft to help cut down on vibration & alignment issues and keep the main section as high as possible so it doesn’t “drag”. Another problem was the 16 gallon gas tank; it was in the center of the vehicle. I’m using the Dana 44 springs and all mounting brackets, shocks and steering box from the front of the 79 Power Wagon the motor came from, for the front end.  

3836bbl 3836bbl
Enthusiast | Posts: 407 | Joined: 11/10
Posted: 02/03/11
07:35 PM

kwhooler sound like a man with a plan. The 5.9ltr Magnum is available in most Dodge pick-up trucks. There was a 5.9ltr R/T version of the Dakota 99-2001 they were impressive performers. You could get 1 cheap use the computer & harness out of the same truck & have an EFI with OD & have the best of both worlds. As far as the fuel tank goes if you have the room add another 16gal. tank with a cross over tube to double the fuel capasity. Post some photos if you get a chance it sounds interesting at the least. Don't ask me how I'm clueless on that stuff. LOL. Good luck Happy Moparing.   3836bbl/Budnicks  
"Fill Your Library Before Your Fill Your Garage"  3836bbl alias Budnicks