Retro-fitting a roller cam in non-roller block

[Aussie XAXB]

Has anyone used one of the retrofit hydraulic roller kit in an older non-roller block? I am considering trying one. I have been to Crane and Comp Cams sites. Crane only seems to offer 2 cams for this and Comp offers about 5 or 6. Comp Cams site specifies that you cannot use the retro cams in an original roller block due to a difference in base circles. So it would seem that you would have to use a retro fit cam only in an old block. But then their kit specifies that with it you can install any of their hydraulic roller cams in a non-roller block, but warns to confirm same base circle. Looks like I may need to give them a call.

Another consideration is routing spark plug wires to the firing order of the cam. Won't that mess with what pistom is at the top ready to fire??? Seems weird to me.



Steve

[tmoss]

Before you call them, check the diameter of the cam on the end from the block you are going to use so they know what your base circle is.  Don't know what the 5.0 is off the top of my head.

[Evil95GT]

Steve,
Just FYI, Jerry is gonna help me write detailed instructions for you tonight. Look for them around midnight.

[Evil95GT]

Steve,
There's a kit made by Ford Racing. You can see it on Summit's Website.......just click this ~~~> http://store.summitracing.com/default.asp?target=esearch.asp&N=110&Ntk=KeywordSearch&Ntt=roller+cam+conversion

The PN is FMS-M-6253-A50 and it sells for $58.69. You'll need that, along with lifters, and the necessary provisions made to your existing block.

P.S. That firing order thing is confusing me. The Lunati 1087 I ran had a 351 firing order, and guess what...........it's IDENTICAL!

[Aussie XAXB]

That kit says it's for 1986 and later engines though?? Our's, if not a 1968, is at least older than 1986.  Is it still gonna work? Price is good though.

Steve

[cmccarthy]

Yes, you'll just need to swap the plug wires around to the 5.0 HO/351 Windsor firing order. That's the only difference.

[Aussie XAXB]

I read that before too......but what about the timing of which piston will be at TDC??? I understand how firing order is related to the cam, but the pistons will still be moving the same as with the current cam.....so what happens??

If the new firing order says to fire cylinder 3 when cylinder 5 is at TDC.......well, you get the picture.

Steve

[Freakingstang]

I hate to be the barer of bad news, but that kit cannot be used on a non roller block.  Here is why:

The newer roller blocks have a deeper lifter bore for the extended length of the roller lifter.  If you put a roller lifter into a nonroller block, the lifter will come too far out of the bore and suck air through the oil hole and will lose pressure.  (the hydrualic lifter won't be hydraulic anymore and the plunger will bottom out, or collapse.) 


The correct way to do this is by using the kits offered by Crane, Comp cams, etc.  But it really limits the cam selection you have.  Personally, I would either stick with the flat tappet cam or pick up a newer 302 roller block.

Steve

[Freakingstang]

I read that before too......but what about the timing of which piston will be at TDC??? I understand how firing order is related to the cam, but the pistons will still be moving the same as with the current cam.....so what happens??

If the new firing order says to fire cylinder 3 when cylinder 5 is at TDC.......well, you get the picture.

Steve

The piston will always travel at the same rate.  And firing occurs at TDC (with no advance or retard of the ignition timing). Now the cam controls when the valves open and close for the 4 stroke cycle.  You have to change the firing order, because the cam valve events are now are differant times.  The cam decides what firing order you need to run.

Old 302's 1-5-4-2-6-3-7-8

5.0L H.O. and 351 1-3-7-2-6-5-4-8

The lobes for the coresponding cylinders on a roller cam match the roller firing order.  The lobes on a flat tappet cam match the nonroller firing order.

Hope I didn't confuse you any more.

Steve

[Aussie XAXB]

I had forgot that the firing order can be 180 deg. different because of the 4-stroke nature of the engine. I was just thinking that the cam was going to be opening and closing valves out of sinc with the crank.

I found a killer Lunati roller cam that will fit in my block. I'll be going with it and a retro kit.

Thanks for all the help everyone!! 

Steve