SoCal Jet Boats
Tech Talk => Engine Mechanical / Electrical => Topic started by: ryanbrindle on March 13, 2008, 11:10:22 PM
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Well i bought a cam. Should work out pretty good! Not to radical but should have a decent sound to it. Here are the specs:
Duration at .050, Int. 204, Exh. 214
Adv. duration Int. 282, Exh. 292
Valve lift Int. .490. Exh. .516
Center lobe Int. 107 Exh. 117
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Centerline on intake is 107 and ex 117? Very odd
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Centerline on intake is 107 and ex 117? Very odd
What do you think it will do with a center like that?
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Lobe seperation will determine how much overlap the cam has and how it will function.
Lobe centerline spec is determined with cam set straight up and can be altered by advancing or retarding the cam (if I remember correctly).
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Anyone care to comment on the effects of have a center lobe degree like I bought would do?
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I'm trying to look up some info. I'll get back soon.
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I'm trying to look up some info. I'll get back soon.
Cool man! Just curious as to what to expect considering idleing. Says the power range is from 1200rpm to 4700rpm
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Is this cam for a 460 and who made it hyd flat what a bout carb heads etc
is this for the omega boat or ?
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Informantion borrowed from an older Holley/lunati catalog
"CAM CENTERLINE is another term which is critical in defining camshafts. Cam centerline refers to the actual cam phasing or timing with relation to the crankshaft. Specifically, where the actual centerline of the #1 cylinder intake lobe is in relation to the #1 piston, defined in degrees of crank rotation AFTER TOP CENTER. It is one of the methods of defining cam "degreeing"."
"CAM LOBE SEPERATION is used to define the actual spacing of the intake and exhaust lobes from each other, for the same cylinder. It is a fixed amount, ground into the shaft at the time of manufacture."
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Is this cam for a 460 and who made it hyd flat what a bout carb heads etc
is this for the omega boat or ?
Its for a 460. The cam is a Melling hyd. The carb is I believe a 750 holley. Heads are stock but might get some massaging soon. Its going in my sanger.
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And its just a cruiser with a basically stock engine.
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A lot of guys will recommend advancing the cam when you "degree" it in the engine, but most cam grinders recommend installing it straight up, because that is how they designed it to work.
Adjusting the cam timing is something that would be a good test on a dyno, but for your application stick it in, degree it to make sure there is no problem and run it.
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should work ok , would like to see your sanger will have mine wired Friday. and
ready to test ,at river come by some time need help to launch if you want a ride
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should work ok , would like to see your sanger will have mine wired Friday. and
ready to test ,at river come by some time need help to launch if you want a ride
Just let me know when you want to do it. my number is 760-646-3655.
crewchief, thanks for the help!!!
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Glad the useless information (as my wife calls just about everything in my head) was good for something ;D
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thanks will call you motor ready wireing al most they may bring rock for drive way
friday but hold on to (satday :banghead: ) or next week will be soon (its a slow ride
flat bootom)and an old man ;D
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i think the lobe center difference is a crutch for the so called bad exhaust port on the ford.
not real sure why they did so much though.
edit: only the cam grinder/manufacture would know, call and ask. as well did they take into consideration that the engine would have wet exhaust
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I don't see anything wrong with that separation, that's pretty normal nowadays. On the old grinds, they always kept thinks the same, LC 100, ICA 110 - Now crane, etc all move things around to optimize the cam.
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I don't see anything wrong with that separation, that's pretty normal nowadays. On the old grinds, they always kept thinks the same, LC 100, ICA 110 - Now crane, etc all move things around to optimize the cam.
not saying thats anything is wrong, just trying to understand why they did it like that.
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A lot of guys will recommend advancing the cam when you "degree" it in the engine, but most cam grinders recommend installing it straight up, because that is how they designed it to work.
Adjusting the cam timing is something that would be a good test on a dyno, but for your application stick it in, degree it to make sure there is no problem and run it.
Mass produced cams are a joke sometimes. The custom grinds like Ralph has is the best way to be accurate. Just a few weeks ago I degreed a cam in straightup, and the manufacture stated it should be on a 110 lobe centerline, but after degreeing it is was on a 117* :screwy: After checking the lift and duration as well we're a bit off. But that's what you get sometimes, the masters on the cam grinders wear out a little after being used after so long. And it's also weird that alot of different brand cams are the same. I've measure on a cam doctor a crower cam compared to a Crane cam and they we're the same specs. I hear there is a HUGE cam grinder in Detroit that grinds the majority of off the shelf cams.
But I think Ralph might be right, they might be compensating the shitty Ford exhaust, possibly trying to build up cylinder pressure to get it through faster?
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with that duration she he be worried about reversion ???
mine is close to that and i will be running the bassett t-valve with a manual valve under the seat so i can control the water better. might be over-kill but, something to think about.
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Adjusting the cam timing is something that would be a good test on a dyno, but for your application stick it in, degree it to make sure there is no problem and run it.
Mass produced cams are a joke sometimes. The custom grinds like Ralph has is the best way to be accurate. Just a few weeks ago I degreed a cam in straightup, and the manufacture stated it should be on a 110 lobe centerline, but after degreeing it is was on a 117* :screwy:
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Problem :banghead: :mad:
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Problem :banghead: :mad:
When I installed my cam in my old 427 I just installed it using the 0 degree bushing. Ended up taking the engine to a pro and the cam was 7 degree's retarded. :banghead:
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Usually you find the ICA that the cam is supposed to be at - and degree it so that is where it is and move it from there. Advancing the cam 4 degrees from installed, isn't the same as advancing it 4 degrees from where it should have been....
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The cam you have selected is smaller than the stock as installed jetboat typical cam from Hardin,glenwood,etc. in their 310-330hp motors. Your cam will have almost a dead smooth idle, and lose about 20 HP from their stock installation. Their cam is 214/218 deg at .050, and lift is about .461/.480 on 115 deg lobe seperation. Log exhausts can easily use 224 to 230 deg at .050 without reversion problems. If excessive idleing isn't anticipated you can run up to 244 at .050 with logs, and we have installed many cams of that size with no problems. BUT you must drill idle air bypass holes in the primary butterflies (.100"), tune the carb for the best idle possible, and shorten up the total advance to allow 12-15 degrees of timing at idle. TIMINATOR