since i am keeping my olds 455 i need to know if the new cam i just bought was a wrong choice,.when the motor was running in the lake it didnt seem like it was sucking in water back through the ex , but im not sure , my ex system is a log setup and the outlets sit compleltly under water when the boat is not moving ,.. so as i understand , the more "lumpier" the cam is the more chance there is for EX reversion ? ,.. is this too steep of a cam ?


Duration Advertised 288° Intake/298° Exhaust

Duration @ .050'' 214° Intake/224° Exhaust

Lift @ Valve .472'' Intake/.496'' Exhaust

Lift @ Cam .295'' Intake/.310'' Exhaust

Lobe Separation Angle 112°

Intake Centerline 107°

Intake Timing @ .050"  Open 0° ATDC-Close 34° ABDC

Exhaust Timing @ .050"  Open 49° BBDC--Close 5° BTDC

i think anything under 250 at 50 duration you should be ok

so will it be ok or no ?

not to be rude but i literally have no clue what you are talking about haha

ok well i have a question for you!   how did you make the choise for this cam?  what the compresion for your motor? and what intake do you have?

ok well i have a question for you!   how did you make the choise for this cam?  what the compresion for your motor? and what intake do you have?

i had a broken lifter  , and after i did some searching around i thought that i couldnt buy just one lifter (now i know that was wrong),.and everybody was saying that you HAVE  to replace the cam when you replace the lifters, or it will wear out the old cam ,.so while going down every wrong road when i was trying to get this boat running , i went to Jegs and bought the Edlebrock performer Cam & Lifter set for a cheap $200 shipped

the motor is all stock from a '75 olds 88 ,.. stock 8.5 (?) pistons and stock low rise manifold

ok the reason i asked is cause you have to be careful about cam choice. to big and waist. motor wont run right. to small huge loss of power.  if you have NOT pulled it apart then just fix the lifter. that cam maybe to big for a stock motor.NOT positive but im pretty sure. If it were me id just go get a set of stock lifters and run em.

i have already installed the cam and lifters and tried to break in the cam but ended up just breaking the motor LOL ,.. pretty much spun every bearing in the fawker except the cam bearings ,..but that was a oiling issue 


so  thats why im trying to get all the right parts together while im getting the block and heads rebuilt,.would it be Ok to throw the old cam in there with the edlebrock lifters ?


but then again even this "car" cam might have too much of a lift , no ?

the way it ran with that cam it was slightly "lumpy" and it never got past 4500 rpm ,.. some people are saying that with a too aggressive cam it will not allow the motor to turn full RPM's because its not even in the RPM's where it makes most TQ , so this does not allow the jet pump to turn  at a high enough RPM to allow the engine to turn 5K+



Hmmm,.WTF to do ? 

try this cam ?

use old cam ?


OR spend another $400 for a "marine" cam  with a smoother idle ? with say 240-250 insted of 290-310  ?



one more question if you guys dont mind , when the problem of EX reversion occures ,..

is it the cooling water coming out of the EX that gets sucked back into the engine ?

or is it from the outside pressure of the lake water that gets sucked into the engine ? this only being a proble while the EX tips are under water

i think anything under 250 at 50 duration you should be ok

Theres your answer right there

Eddy Cam: Duration @ .050'' 214° Intake/224° Exhaust

i have already installed the cam and lifters and tried to break in the cam but ended up just breaking the motor LOL ,.. pretty much spun every bearing in the fawker except the cam bearings ,..but that was a oiling issue 


so  thats why im trying to get all the right parts together while im getting the block and heads rebuilt,.would it be Ok to throw the old cam in there with the edlebrock lifters ? Why destroy new lifters?


but then again even this "car" cam might have too much of a lift , no ?
No, Delta 88 455? probably a smog cam

the way it ran with that cam it was slightly "lumpy" and it never got past 4500 rpm ,.. some people are saying that with a too aggressive cam it will not allow the motor to turn full RPM's because its not even in the RPM's where it makes most TQ , so this does not allow the jet pump to turn  at a high enough RPM to allow the engine to turn 5K+

never went past 4500 rpm = 325+/- hp, 5000 r's requires more hp
Eddy Performer rpm would be a good choice too



Hmmm,.WTF to do ? 

try this cam ? I would

use old cam ? scrap it


OR spend another $400 for a "marine" cam  with a smoother idle ? with say 240-250 insted of 290-310  ? .295"/.310" is lobe lift, 240*-250* is .050" duration. A marine cam typicaly has smoother/slower idle for shifting (Mercruiser, etc.) you are already at 214*/224*, My BBC has 238*/242* ,  .575"/.578" lift, through logs and snails, and no reversion



one more question if you guys dont mind , when the problem of EX reversion occures ,..It SHOULDNT

is it the cooling water coming out of the EX that gets sucked back into the engine ? It can

or is it from the outside pressure of the lake water that gets sucked into the engine ? this only being a proble while the EX tips are under water its possible

Hope that helps

Daniel
Mash on it

Theres your answer right there

Eddy Cam: Duration @ .050'' 214° Intake/224° Exhaust








Hope that helps

Daniel
Mash on it

That helped alot man , big thanks to you and everybody else for the help !! so if i understand it right , it Should be ok right ?


and the reason Marine cams have asmoother idle is for boats with gearboxes ?

anything under 250 at 50* duration between the ex and intake stroke of the cam , it should be fine since im at 214-224 ?  LOL 

why destroy new lifters ?  - im a idiot that seems to break good parts for no reason haha 

yup ,Delta 88 smog J head bearing spinning no more than 45mph turd 455  ,..good to know it was just low on HP though and not a waterlogged hull