which camshaft?

[96DONZI]

have a 96 sweet 16 with stock 350 4V. any suggestions on a better cam without having to get into better valve springs, roller rockers, etc.? I'd just like to get a little more performance with a quick and dirty camshaft change. a little lumpy idle wouldn't hurt my feelings either!!

[Woodsy]

Your better off playing with props to get more juice. A cam change without any other upgrades could cause some serious reversion. The lumpier the idle the better the chance reversion is occuring....

Woodsy

[Rootsy]

whatcha running for a prop right now... how many rpms is she turning and what gps speeds??? the stock 350 in your boat should have been a 2V.. has someone swapped the motor or the induction?

you aren't going to swap to a "performance" type camshaft without doing a good part of the valvetrain along with it... btw, your motor should have a flat tappet camshaft if no one has changed it or the motor...

do you have thru-hulls or are you pushing all of the exhaust through the propeller?

if all you want are a few mph then i agree with woodsy and say play the prop game...

humbly
J

[RickSE]

Crane used to have a nice 272(I)/284(E) Duration, 454"(I)/480"(E) Lift marine cam for these motors, but I just looked and can't seem to find it. You would have to change valve springs though with this cam. Changing the springs is no biggie especially since you have to pull the motor anyway to change the cam. I used this cam when I upgraded my 1996 350 2V to a 4V several years ago and had good results.

[Sam]

Ditto to what Woodsy and Rootsy said. Props can provide cheap speed gains and you can do it at the ramp :biggrin: .

Sam

[tomboyea123]

im putting in a cam today. I am going with a comp cam high energy 212 218 with a 447 472? lift with a 112 centerline.This is a marine cam. I am also going with ported vortec heads with 202 and 160 valves,an air gap manifold and a 600 holley marine carb. I think this setup will make pretty good power till 4800-5000 rpm. I will keep you posted on results.I was going to put in a marine comp cam with a 218 218 duration on a 110 centerline but I though it was a little too lumpy for the boating I do at 9000 ft.

[tomboyea123]

I have the bigger cam if you are interested.

[mrfixxall]

you may want to get a bigger carb min 650cfm with mec secondarys,,,,,if you decide to stick with the 600 keep a eye on your plugs at wot so you dont suck the intake valves...

[tmdog]

96DONZI- - My 350 block is bored 60 over w/ Vortec heads and a Performer Rpm intake topped w/ a 750 Holley. The cam I choose was a Comp Cam XM270H. Duration at 050, I-226 E-236 Lift .480 and .489, 112 lobe sep. and Comp roller rockers. Gave the 18 C very good torq. and enough HP to run in the low 70's at 53-5400 rpm w/ a turbo1 23p. The cam gives a decent lumpy idle and running EMI exhaust with the long risers. Not even a hint of reversion. Now the cat is out of the bag.

[mrfixxall]

great cam tmdog,,,i run 350 030 over,brandt crank, oliver 6.0 rods,srp forged flatop,comp camcsxm 270h-12,edlbroch performer rpm 2.02I 1.60E fully ported and flowed 70 cc,edlbroch air gap flowed, 750----930 cfm proform blue printed carb and also emi power flo exhaust ....14x24 ultra prop,, wingin the motor to 6200 rpm due to i cant find the rite prop in the rite price range......

[tmdog]

What's your speed w/ the 14x24? Salt or fresh? Just caught you home state. We know it is fresh.

[mrfixxall]

with a full tank and smooth water gps 68mph at 5900-6000 rpm,,,1/4 tank and two footers it will tiptoe in to the 70's and the tach will go over 6200............but i dont want to push it,, ive seen 6400 on the tach but that when the fuel guage was on e,,,,,for enuff screwing around lol......

[tmdog]

If you are turning that kind of rpm w/24 and getting the speed you noted, something is wrong. Either a lot of slip or cavitation. I may be wrong but the math don't add up. At 70mph @6200= 93-94 mph theoretical. Slip is at 25% plus or minus. That's a bunch. Maybe bad tach? MPH sounds good = good HP & torque.

[mrfixxall]

i have a 1.61 ratio,,,slipage???? yes mabe too much...the tach i checked with gafferig and tried others ,,the same rpm...the boat dont like this prop if i turn sharp it will blow out and sometimes going straight...its the volvo drive slowing me down.. i use to have a 15x25 oj bronze prop,,,,that the boat really liked but i hit somthing undr the water and tore a ear off and nobody could fix it so i threw it away...the boat use to have a lt1 in it and did 75 ish on speedo , this was before gps....

[tmdog]

Mrfixxall- - You have a private mess.

[BRIAN73]

Mr.fixxall,

what are you estimating for horsepower??

I seen some 18s with close to 425hp in them struggle to reach 70 with a standard 270 or 280 volvo, swinging a 24 pitch prop.

Brian

[mrfixxall]

on dyno,434 hp 410 ft tq