cam swap

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93toyota

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can a hyd. roller cam motor be converted to accept a solit roller cam or a diiferent cam? how?
 
Yes, But only on the earlier versions, non magnum as they have the same size brgs. The magnum engines have a larger size journal and would require a custom cam, as I'm not sure if anyone is building a performance cam for them yet. But then you would have to look at the cost effectiveness of what your trying to do. Also you would have to change the pushrods as the lifters are shorter, to the nonmagnum style.


BJR Racing
 
my motor is not a magnum. So I can put any non magnum cam in my motor and just change the pushrods and lifters?
 
if I'm reading your post right BJR- your saying tat magnum cam journals are bigger? because that isn't right, they use that same cam bearings as 74' and up- I've used a Magnum block and used an earlier cam in it. The one difference is the cam snout- the magnum uses a different timing set and since a mag doesnt require a fuel pump eccentric the snout is shorter.
 
Mrspeeddemon,
The cam brg. book that I have shows the 57-79 cam brgs. take a different brg. than the newer version as the counter bore is 2.130 with a .875 length and a .0645 thickness. On 4 out of the 5 that they take. The newer brgs. are for 80-99 shows 3 different counter bores depending on the position which are, 2.0830, 2.0990, and 2.130 with the length of them varying from .615 to .625 with one at .930, and the thickness of .645. So I would have to believe the manufacturer is correct as they get there specs from Chrysler to make the brgs.. Also the eariler brgs. have oil holes for the heads to get oil to the rockers and the magnums don't as they oil through the lifters like a chevy, thus the oil passage in the block is blocked, or not drilled.
If you have a magnum block with a older set of cam brgs. in it then someone had to have done some reaming on the brgs. as they should have been very tight just due to the counter bore size being different.
If the counter bore is different in the block and the brgs. are the same thickness then the cam has to reflect the change also. The journals are thinner than the earilier versions also, so if what your saying is true then the newer cam should fit in the older block which maybe true but the oil pressure would be lacking due to too much clearence.


BJR Racing
 
Apparently you have never measured any of this for yourself- or you wouldn't be trying to argue with me. I have measured- your book says 57-79- ok whatever, most books list as 67-74 but I've seen blocks later than 74 use the earlier bearing or visa versa. And your books states that 80-99 uses a the later bearing- well mags didn't start in 1980 so that must mean that those bearings will work for both magnum and premagnum engines and since I'm sure that when you order an aftermarket camshaft they don't ask you what year small block your working on(I know I've never been asked) that all the camshafts use the same size cam journal. The reason that they changed the bearing is the width of the bearing .875" to .930" but I've ball mic'ed a couple sets of early and late bearings and I've never found a difference in the thickness (even though my book lists different thickness's too) Right now I can't remember if I ever measured the dia. or not. And as for the extra oil holes in the bearings- who cares- if theres not a hole in the block then it doesn't matter (I have seen quite a few magnum blocks that were drilled however). I'm not trying to pick a fight with you here- I just want to make sure that people looking for information aren't missinformed. :thumblef:
 
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