Cam Questions - Little Help/Direction needed
11-06-2014 | 04:25 PM
#1
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Joined: Jun 2006
Posts: 5,117
Likes: 959
From: Seaford, VA
Cam Questions - Little Help/Direction needed
My boat is going through a refresh this winter. I had some salt water get in my motor through a leaking head (and headers, and headgasket) and am rebuilding. On top of that it has just gotten to the age it needs some attention (new guages, indicator cables, shift cables, TA rebuilds, etc....).
I had one MK IV and one Gen VI in my boat. The IV crapped out on me. Luckily my buddy had a spare VI that he has given me. I am going to refresh the bottom end and then swap my Roller Rockers (Crane 1.7) and Springs onto his motor.
I believe that both of my Cam's are the factory 502 415HP cam. I believe the stock specs are Intake - 211, Exhaust - 227, and if I'm reading this right the lift is only .301?? Not sure of the LSA.
I know this isn't the "right" cam. I run Weiand 177's with the small pulley on them so I can't imagine a cam this mild is the right cam for me.
I guess my real question is can I get by with this cam for a couple years until I am ready to do a full refresh on both motors? The way we use the boat is 75% idle 25% 33-3700RPM cruise. I know I can call Bob M, but I'm not really in a financial position to drop too much money on this rebuild and don't want to tie up his time if I can't afford to work with him.
I might change both cams if Summit/Jegs has something off the shelf that you guys would recommend and I could wake these things up for a couple hundred bucks a motor, but I might also just throw this one back in and go a few seasons - I put about 10 hours on it last season.
Can you guys give me some thoughts/direction?
Thanks,
Eric
I had one MK IV and one Gen VI in my boat. The IV crapped out on me. Luckily my buddy had a spare VI that he has given me. I am going to refresh the bottom end and then swap my Roller Rockers (Crane 1.7) and Springs onto his motor.
I believe that both of my Cam's are the factory 502 415HP cam. I believe the stock specs are Intake - 211, Exhaust - 227, and if I'm reading this right the lift is only .301?? Not sure of the LSA.
I know this isn't the "right" cam. I run Weiand 177's with the small pulley on them so I can't imagine a cam this mild is the right cam for me.
I guess my real question is can I get by with this cam for a couple years until I am ready to do a full refresh on both motors? The way we use the boat is 75% idle 25% 33-3700RPM cruise. I know I can call Bob M, but I'm not really in a financial position to drop too much money on this rebuild and don't want to tie up his time if I can't afford to work with him.
I might change both cams if Summit/Jegs has something off the shelf that you guys would recommend and I could wake these things up for a couple hundred bucks a motor, but I might also just throw this one back in and go a few seasons - I put about 10 hours on it last season.
Can you guys give me some thoughts/direction?
Thanks,
Eric
11-06-2014 | 05:55 PM
#4
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Joined: Jul 2004
Posts: 11,332
Likes: 73
From: chicago
Without a doubt, considering you are running a supercharger, there is alot of power on the table with cam swap and exhaust.
Of course you can run those cams as is, but yes, you are throwing some performance away. Only you are the person that can answer whether or not it's enough power lol
Sometimes you can find some good deals on takeout merc cams here in the swap shop. Even a 500EFI cam would be a big step up from what you have there. But exhaust needs to get installed before any other mods IMO.
Of course you can run those cams as is, but yes, you are throwing some performance away. Only you are the person that can answer whether or not it's enough power lol
Sometimes you can find some good deals on takeout merc cams here in the swap shop. Even a 500EFI cam would be a big step up from what you have there. But exhaust needs to get installed before any other mods IMO.
11-06-2014 | 05:57 PM
#5
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Joined: Jun 2006
Posts: 5,117
Likes: 959
From: Seaford, VA
I was jotting numbers down fast so I am not even sure the .301 lift is accurate, but figured you guys would know the factory specs on the 415hp 502
11-06-2014 | 06:56 PM
#7
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Joined: Nov 2004
Posts: 14,068
Likes: 3,668
From: On A Dirt Floor
Could be anything from Runs New. There have been a lot of problems on multiple forums with there motors.
Just sayin !
And Rmbuilder - good info.
Those .200" numbers of the factory cam are absolutely not getting anything done...are they. LOL.
Obviously everyone with a BBC knows about the non existent lift of this cam.
==========================
Seaford guy - here is the skinny plain and simple.
Not only is that cam a lame duck, the GM springs used for this cam are lame also.
So, going to a cam that your motor wants real bad, is going to require more than changing the cam. You are looking at a complete valvetrain overhaul. Cam, springs, pushrods, rockers, and etc,etc.
Doing things on the cheap does not always mean inexpensive.
Doing things on the cheap (in our world) means getting the correct pieces in order, assembling them correctly, and then as far as actual cost, not paying Mercruiser type prices.
This is the beauty of RmBuilder. He knows what pieces are needed and can supply them to you at prices the common working man is comfortable with.
He, like I, don't supply Pixie Dust.
So, if you just have a few hundred to spend, it's going to have to keep the stock cam.
Just sayin !
And Rmbuilder - good info.
Those .200" numbers of the factory cam are absolutely not getting anything done...are they. LOL.
Obviously everyone with a BBC knows about the non existent lift of this cam.
==========================
Seaford guy - here is the skinny plain and simple.
Not only is that cam a lame duck, the GM springs used for this cam are lame also.
So, going to a cam that your motor wants real bad, is going to require more than changing the cam. You are looking at a complete valvetrain overhaul. Cam, springs, pushrods, rockers, and etc,etc.
Doing things on the cheap does not always mean inexpensive.
Doing things on the cheap (in our world) means getting the correct pieces in order, assembling them correctly, and then as far as actual cost, not paying Mercruiser type prices.
This is the beauty of RmBuilder. He knows what pieces are needed and can supply them to you at prices the common working man is comfortable with.
He, like I, don't supply Pixie Dust.
So, if you just have a few hundred to spend, it's going to have to keep the stock cam.
11-06-2014 | 09:43 PM
#8
Thread Starter
Gold Member
Joined: Jun 2006
Posts: 5,117
Likes: 959
From: Seaford, VA
Could be anything from Runs New. There have been a lot of problems on multiple forums with there motors.
Just sayin !
And Rmbuilder - good info.
Those .200" numbers of the factory cam are absolutely not getting anything done...are they. LOL.
Obviously everyone with a BBC knows about the non existent lift of this cam.
==========================
Seaford guy - here is the skinny plain and simple.
Not only is that cam a lame duck, the GM springs used for this cam are lame also.
So, going to a cam that your motor wants real bad, is going to require more than changing the cam. You are looking at a complete valvetrain overhaul. Cam, springs, pushrods, rockers, and etc,etc.
Doing things on the cheap does not always mean inexpensive.
Doing things on the cheap (in our world) means getting the correct pieces in order, assembling them correctly, and then as far as actual cost, not paying Mercruiser type prices.
This is the beauty of RmBuilder. He knows what pieces are needed and can supply them to you at prices the common working man is comfortable with.
He, like I, don't supply Pixie Dust.
So, if you just have a few hundred to spend, it's going to have to keep the stock cam.
Just sayin !
And Rmbuilder - good info.
Those .200" numbers of the factory cam are absolutely not getting anything done...are they. LOL.
Obviously everyone with a BBC knows about the non existent lift of this cam.
==========================
Seaford guy - here is the skinny plain and simple.
Not only is that cam a lame duck, the GM springs used for this cam are lame also.
So, going to a cam that your motor wants real bad, is going to require more than changing the cam. You are looking at a complete valvetrain overhaul. Cam, springs, pushrods, rockers, and etc,etc.
Doing things on the cheap does not always mean inexpensive.
Doing things on the cheap (in our world) means getting the correct pieces in order, assembling them correctly, and then as far as actual cost, not paying Mercruiser type prices.
This is the beauty of RmBuilder. He knows what pieces are needed and can supply them to you at prices the common working man is comfortable with.
He, like I, don't supply Pixie Dust.
So, if you just have a few hundred to spend, it's going to have to keep the stock cam.
If I can't reuse my rockers and springs then I'll probably just throw it back together as is because I am guessing I am raising my budget significantly. I am under no illusion this could be corrected for a couple hundred dollars but I don't want to get into a couple thousand. If I could get the right cam in them for 1000-1500 then I might have to consider it.
11-06-2014 | 09:46 PM
#9
Thread Starter
Gold Member
Joined: Jun 2006
Posts: 5,117
Likes: 959
From: Seaford, VA
Without a doubt, considering you are running a supercharger, there is alot of power on the table with cam swap and exhaust.
Of course you can run those cams as is, but yes, you are throwing some performance away. Only you are the person that can answer whether or not it's enough power lol
Sometimes you can find some good deals on takeout merc cams here in the swap shop. Even a 500EFI cam would be a big step up from what you have there. But exhaust needs to get installed before any other mods IMO.
Of course you can run those cams as is, but yes, you are throwing some performance away. Only you are the person that can answer whether or not it's enough power lol
Sometimes you can find some good deals on takeout merc cams here in the swap shop. Even a 500EFI cam would be a big step up from what you have there. But exhaust needs to get installed before any other mods IMO.
