i have a 72 4x4 with 3.55s 727 33 in tires... 360 .60 over, rv cam, high volume oil pump, edelbrock performer intake and performer carb. 600cfm, Headers and 3 in single exhaust with a flowmaster. im guessing round 300hp?!?! dont know for sure... but what woudl porting and polishing the stock heads on it gain me?... i have plenty of power round 3500 and up, i need more low end torque without changing gears. any suggestions on any upgrades and what would the heads accomplish?
Speed Dragon
03-18-2008, 07:39 AM
Porting could actually lose more low end. With your setup you should have plenty of low end, if anything you should being starting to run out of power in the upper revs. You sure it's an RV cam? Did you or someone else build the engine, and was it built for a truck or a car? What is the timing set at?
w100 360ci
03-18-2008, 10:58 AM
yes see thats what i though...i built the motor for my truck...and i said i wanted an r.v. cam at the machine shop its mopar performance... maybe its not...idk maybe im just expecting too much out of my truck... what i need is to ride in a truck pulling with a stock 360 to see where im at
Speed Dragon
03-18-2008, 03:28 PM
Well, I had a 360 w/ a Purple Shaft cam, a Victor 340 intake and a Holley 4bbl in my truck at one time, w/ a 727 trans. It was a little doggy below 3k, but after that it'd pull as long as you had your foot in it. You could punch it at 80 and feel it pulling. With a 318 2bbl on it, it was better down low but ran out around 6k.
Did you assemble the engine, or the machine shop do it? Did you/they degree the cam, or advance or retard it? What's the ignition timing at?
w100 360ci
03-18-2008, 10:18 PM
10 dergrees in advance... i did most of it...the cam was in it when i got it back though but you could see the purple paint on it... if that means anything
Speed Dragon
03-19-2008, 09:50 AM
Holy cow, 10*?? Something isn't right, it shouldn't be advanced more than 4. There's a saying that if you have to advance the cam more than 4*, you have the wrong cam. If it's advanced 10 and still is doggy on the bottom end, it's definitely not the right cam, and definitely not an RV cam.
bherder
03-19-2008, 04:29 PM
I think he means 10* ignition timing ... :dunno: ??
B-300
03-19-2008, 04:51 PM
The first 360 engine I built 20 yrs ago had to low of a compression ratio for an RV cam... 7.8 to 1. I built another engine a year later using Sterling H405 pistons (Hyperutectic, bought from Jasper speed and marine) which are 0.045" taller and increased the compression ratio to 8.8 to 1. You could remove your heads and have them machined to increase the CR without a complete redo.
I ended up with timing at 15 degrees initial and reduced the centrifugal advance by about 5 degrees to prevent ping at higher rpm.
w100 360ci
03-19-2008, 09:24 PM
yeah 10 inginition... i guess i have no idea was cam timing or whatever is... but i was screwing around with it today and unhooked the kickdown linkage and i hvae about another 2 inches of pedal and it never worked anyway you have to shift it up and down by hand
Speed Dragon
03-19-2008, 11:46 PM
Oh, sounded like he was saying the cam was advanced 10* :crazy: In that case, the only thing I can think of is either the carb is too big, or it's a bigger cam than it's supposed to be.
bherder
03-20-2008, 02:07 AM
yeah 10 inginition... i guess i have no idea was cam timing or whatever is... but i was screwing around with it today and unhooked the kickdown linkage and i hvae about another 2 inches of pedal and it never worked anyway you have to shift it up and down by hand
Ya better hook that kick-down linkage hooked back up before ya destroy the tranny.... Get it hooked up/adjusted right.... You should never have to 'shift gears by hand' (unless you WANT to, of course...)
w100 360ci
03-21-2008, 12:10 AM
its never worked and ive been doing it for 3 years now hauling all kinds of trailers around 10 000 lbs plus loads
Speed Dragon
03-21-2008, 09:21 AM
It doesn't work because it's adjusted wrong. If you set it right, it will work just fine.
bherder
03-21-2008, 03:05 PM
its never worked and ive been doing it for 3 years now hauling all kinds of trailers around 10 000 lbs plus loads
I'm guessing you've been lucky :D (Although, a 727 is pretty much a 'Super-Man' of trannies ;) )
Still, as Speed says, it's better to have it hooked up and adjusted just right... Not terribly difficult or anything.... ;)
buck99
03-22-2008, 10:23 AM
Ya....even a 727 will blow up if the linkage isn't adjusted right. Happened to me.
