genIV cam selection
12-22-2008, 10:57 AM
#21
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The basic difference in the cams is a step on the front of the cam on Gen 5 and 6 whereas the step is not there on a MK-4 cam.
Only the Gen VI cam has the step nose. The Gen V was not a factory hyd. roller motor, so it does not have a step nose. However, they may have made a few Gen V's that were factory hyd. If they did, there were very few.
The step is for a retainer bearing, but not all blocks have the provision for this.
Only the Gen VI cam has the step nose. The Gen V was not a factory hyd. roller motor, so it does not have a step nose. However, they may have made a few Gen V's that were factory hyd. If they did, there were very few.
The step is for a retainer bearing, but not all blocks have the provision for this.
Eddie.
12-22-2008, 11:45 AM
#22
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It is not a bearing, just simply a retainer plate to stop the cam from walking forward. The Mk IV's did not need them since they used a button the rode against the timing cover. Most all Mk IV blocks have 2 tapped holes in the front near the cam to accept the retainer plate. So you can in fact run a Gen VI cam in a Mk IV block. Have done it many times. It is much easier than messing with a cam button to get the right end play. I don't know why you would want to run a Mk IV cam in a Gen VI block, but you can if you want. You just can't use the retainer plate. The only reason would be for availability of a particular cam.
Eddie.
Eddie.
12-22-2008, 11:58 AM
#23
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Boy , i'm sure glad i didnt stir up a bunch of chit ,
if nuthing was asked , nothing would be learned
2 years ago if you asked if 496 manifolds would fit a 454 , there would be a 50/50 split of people saying yes and people saying no , now we all know that they do
my reason for gen 6 cam into a mark-4 is a 500efi cam on ebay thats @ 110.00 with a couple of days left , and i know i need more cam in my engine
i'll probably buy it anyway , and if my block doesnt have the holes for the retainer plate then i'll turn around and sell it for cost to someone who needs a good deal
if nuthing was asked , nothing would be learned
2 years ago if you asked if 496 manifolds would fit a 454 , there would be a 50/50 split of people saying yes and people saying no , now we all know that they do
my reason for gen 6 cam into a mark-4 is a 500efi cam on ebay thats @ 110.00 with a couple of days left , and i know i need more cam in my engine
i'll probably buy it anyway , and if my block doesnt have the holes for the retainer plate then i'll turn around and sell it for cost to someone who needs a good deal
12-22-2008, 03:10 PM
#24
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my reason for gen 6 cam into a mark-4 is a 500efi cam on ebay thats @ 110.00 with a couple of days left , and i know i need more cam in my engine
i'll probably buy it anyway , and if my block doesnt have the holes for the retainer plate then i'll turn around and sell it for cost to someone who needs a good deal
i'll probably buy it anyway , and if my block doesnt have the holes for the retainer plate then i'll turn around and sell it for cost to someone who needs a good deal
Call RMBUILDER and see what he would charge to grind a custom cam for your application. You will be money ahead in the long run, you never know what you are going to get off EBAY
12-22-2008, 03:32 PM
#25
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THe best thing to do is have a cam cut for yourr specific application and then get another one when you change again. Different engine set up, different cam every time.
I have put the stepped nose cam in a MARK IV block several time and have had no problems. I even used regular MARK IV roller lifters in one and havn't had any problems.
Wether this is the most logical way to do something is argumentative, because the designs were changed for a reason. You do need a timing chain for this application. THe MARK 4 won't work. THe MARK IV lifters worked because it was a very small cam. I do remember that the push rod length had to be change, but I don't remember why (besides them obviously not being the right length to get the correct geometry).
Do what you want to do. 9 out of 10 times that you buy a used cam shaft, you end up having to get a new one anyway.
Just get one ordered for your application. A custom, billet core roller cam is only around $400 anyway, and it will perform better, and you won't have to monkey around with it to make it work.
Good luck
I have put the stepped nose cam in a MARK IV block several time and have had no problems. I even used regular MARK IV roller lifters in one and havn't had any problems.
Wether this is the most logical way to do something is argumentative, because the designs were changed for a reason. You do need a timing chain for this application. THe MARK 4 won't work. THe MARK IV lifters worked because it was a very small cam. I do remember that the push rod length had to be change, but I don't remember why (besides them obviously not being the right length to get the correct geometry).
Do what you want to do. 9 out of 10 times that you buy a used cam shaft, you end up having to get a new one anyway.
Just get one ordered for your application. A custom, billet core roller cam is only around $400 anyway, and it will perform better, and you won't have to monkey around with it to make it work.
Good luck
12-22-2008, 03:35 PM
#26
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Boy , i'm sure glad i didnt stir up a bunch of chit ,
if nuthing was asked , nothing would be learned
2 years ago if you asked if 496 manifolds would fit a 454 , there would be a 50/50 split of people saying yes and people saying no , now we all know that they do
my reason for gen 6 cam into a mark-4 is a 500efi cam on ebay thats @ 110.00 with a couple of days left , and i know i need more cam in my engine
i'll probably buy it anyway , and if my block doesnt have the holes for the retainer plate then i'll turn around and sell it for cost to someone who needs a good deal
if nuthing was asked , nothing would be learned
2 years ago if you asked if 496 manifolds would fit a 454 , there would be a 50/50 split of people saying yes and people saying no , now we all know that they do
my reason for gen 6 cam into a mark-4 is a 500efi cam on ebay thats @ 110.00 with a couple of days left , and i know i need more cam in my engine
i'll probably buy it anyway , and if my block doesnt have the holes for the retainer plate then i'll turn around and sell it for cost to someone who needs a good deal
You might as well get one of those cheap flat tappet hydralic cams from crane and a set of $100 lifters. You will have the same outcome, or maybe even better.
Send a message to RMBUILDER, or one of the other guys on the board who do this stuff on a regular basis. Save yourself the heartache and stress.
12-23-2008, 06:25 AM
#28
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I would just go with a crane or comp retro fit hyd roller for the block you have and be done with it...also all the gen IV blocks I've seen are already drilled and tapped, one of the engine I took apart reverse rotation crusader ran the cam gear to gear(so the cam would turn correct direction) and had the retainer plate installed from the factory...Rob
Last edited by ezstriper; 12-23-2008 at 06:30 AM.
12-23-2008, 08:15 AM
#29
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i do appriciate all the input , and believe me i AM listining
and lucky for me its wintertime , 16 degree's outside this morning , pass up on the cam on ebay , and i still have several months before i'm taking away from boating time fooling with my engine upgrades
and lucky for me its wintertime , 16 degree's outside this morning , pass up on the cam on ebay , and i still have several months before i'm taking away from boating time fooling with my engine upgrades
12-23-2008, 09:40 AM
#30
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Boating is only a few months off, its time to get a game plan together so you are ready when it warms up. If you purchase a cam and lifters from RMBUILDER it takes a few weeks (it was 3 weeks for me last Feb).
Get out from behind the couch and get to work
