LA360 Hydraulic Roller Towing Cam

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VF Coupe

VF Coupe

EFI DART
Joined
Sep 14, 2007
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Hey all,
I need a towing cam to go with my 3500lbs Dodge pick-up , for school pick-up , shopping and ski-boat duties!!
I currently have the following going on a local speed-shops recommendation ......
The Howard's quality & finish is amazing !!

Howard's grind no 713175-10
219 @ .050 Intake 225 @ .050 Exhaust
110 Lobe Seperation
but it drinks like my EFI big block dart......!
LA .030" 360 / 365".
This rig only runs on straight Propane
It's has J port heads that are pocket ported that house 2.02/1.6 SI valves , hardened inserts , Comp cams beehive springs & Pac retainers , Crower Collets.
Speedmaster ( I know ) stainless rockers that I'm trying out ,
which have been great with 2000 miles.
The bottom end houses speed-pro hypertecs and pretty much all squared up down there.
No real mods just all cleaned up & de-dagged.
I'm looking at a Crane 699601 Or 699611 what are yawl Haulers running ?
 
Depends on your transmission & rear end gearing.. ,(tire diameter ,comes into play ,too....)Also,how are you tuning it? Propane & big cams,(overlap!) doesn't feel right. Let's get a better idea,of your setup.....
 
Sorry guys she's a 904 Trans with a Std stall of 1,800-2k and a 2:92 rear with a 205/65/14" white wall steelies !!
Impco 425 Mixer and E Model regulator sits on top of a Holley 650 DP throttle base plate!
Air/Fuel ratio is 14:9-15:1 hwy cruise mixture and idle is 12:5-1
full throttle Mixture is 11:9-1
so they R perfect .....!
Timing is 38* total with 16* initial all in by 2000rpm!
 
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I've not ever run any propane so take this with a grain of salt. Your SCR looks to be pretty low for propane, so you gotta make up for it with a lower duration cam. Plus your gearing is all setup for lower RPM's. I'd be going for no more than the Crane 699601 for torque use, and lower duration if I could get it; it'll help pump up the DCR. Keep the LSA to 112 or more. I used to run a 192 @.050" hydraulic flat tappet cam with 114 LSA for economy and torque (in a gas V8 and 3.08 rear gear).

To quote on AFR: "The stoichiometric air/fuel ratio for propane is 15.5-to-1 compared to 14.7-to-1 for gasoline." So if you are tuning to gas engine AFR, you may be tuning a tad too rich for propane. Could 'splain some of the fuel use but most is in the cam and LSA IMHO.
 
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Hey nm9steham,
I did carry out the Propane Stoiciometric value of 15.5-1 in my tune as my AF meter has the ability to switch fuels from Diesel, Methanol, Gasoline and LPG.
Click it out here , it's a great bit of gear !

http://www.mrm-racing.se/bag/analyzer.pdf

I know it's cam related as its the only thing I changed in the build apart from the Valve Diameter!
I sent a custom cam request form into Howard's but no reply , do I just go with the Crane 699601 ??
 
That seems a little big on the duration for towing.
 
OK on the AFR. Thanks for the link; I am getting ready to buy an AFR meter. (Gawd, how did we ever tune carbs without them? LOL!)

IIRC, that is the shortest duration Crane hyd roller listed in their catalog. The .050" duration of 204/214 it getting into torque cam range IMHO. But, yes, there is lower.

BTW, what rocker ratio do you have? 1.6:1 will help in this application. The more ratio you can get, then the lower the duration can be and still keep the lift up a bit. The best torque cams that have good mileage but still can rev up have high lift, and low duration.

I'd call Crane and see what they have. I suspect they have ground many more cams that are not in their catalog than are in it! And I'd follow up with Howard's on the phone. Those stupid forms get lost in someone's inbox all too often.
 
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