383 cam help
Thread Starter
Instructor
Joined: Dec 2005
Posts: 121
Likes: 2
From: Middletown Delaware
383 cam help
For my 383 build I planed on using a Crane small base circle roller cam with with stock roller lifters. Cam is in, drop in a couple lifters add dog bone factory retainer and spider getting ready to do a final valve clearance check. This is the first factory roller motor I have done but IMO I don't think the lifters when in the base position are far enough into the dog bone retainer. I contacted Crane and they said to use a special lifter that is .300' taller. Cost $500+ which is definitely not in the budget. I called them back to check a part # for the lifters, got another tech and was told it would be ok to use the stock lifter. Thoroughly confused I called Comp twice. First call was told to use stock lifters second call told to use tall. I know a lot of members are building these motors. What are you using? All clearances were done with the small base cam. The cam has a base circle of .900" vs stock at about 1.142". I do not have a old stock cam to put in for comparison.
Team Owner
Joined: Aug 2006
Posts: 24,125
Likes: 15
From: Columbia Missouri
Any roller cam built for a later model roller block can be used with factory roller lifters.
Roller cams designed for Gen1 style blocks generally need after market lifters to compensate for the difference is lifter bore design.
If you are using a small base circle cam in a Gen1 engine you will probably need special lifters. If the block is a factory roller block, where you use the stock spider bar and dog bone retainers then that cam will probably work fine.
You can measure the lifter in and out with the cam turning, then measure the oil feed hole, and then compare by measuring down in the bore to see if that oil feed hole both slips down into the oil line and then back up where it seals against the bore wall.
Roller cams designed for Gen1 style blocks generally need after market lifters to compensate for the difference is lifter bore design.
If you are using a small base circle cam in a Gen1 engine you will probably need special lifters. If the block is a factory roller block, where you use the stock spider bar and dog bone retainers then that cam will probably work fine.
You can measure the lifter in and out with the cam turning, then measure the oil feed hole, and then compare by measuring down in the bore to see if that oil feed hole both slips down into the oil line and then back up where it seals against the bore wall.
Thread Starter
Instructor
Joined: Dec 2005
Posts: 121
Likes: 2
From: Middletown Delaware
You make a good point with the oil hole. I will check the measurement and post. That would certainly be a show stopper. The block is a factory roller cam block. I guess my bottom line concern / question is how much of the lifter has to be in the dog bone to be safe?
Team Owner
Joined: Aug 2006
Posts: 24,125
Likes: 15
From: Columbia Missouri
The retainer is simply to keep it from turning. I think at the very LEAST 1/8" of contact in the retainer. The push rod rocker and valve spring keep the lifter on the cam...the retainer is simply there to keep it from turning.
Thread Starter
Instructor
Joined: Dec 2005
Posts: 121
Likes: 2
From: Middletown Delaware
I got the following measurements for the lifter. First I measured the distance from the dog bone flat on the back to the top of the lifter.
@ full lift .43
@ base .115
The Oil feed hole measures from the flat 1.0 to the top of the hole and 1.4 to the bottom.
The lifter has a small hole on one side .8 from the top of the lifter.
The groove in the lifter is 1.090 from the top to 1.7 to the bottom of the groove.
From these measurements the groove in the lifter is always exposed to the oil feed hole. Based on the difference between a small base circle cam and a standard cam a portion of the groove would still be exposed to the oil groove with the standard groove.
@ full lift .43
@ base .115
The Oil feed hole measures from the flat 1.0 to the top of the hole and 1.4 to the bottom.
The lifter has a small hole on one side .8 from the top of the lifter.
The groove in the lifter is 1.090 from the top to 1.7 to the bottom of the groove.
From these measurements the groove in the lifter is always exposed to the oil feed hole. Based on the difference between a small base circle cam and a standard cam a portion of the groove would still be exposed to the oil groove with the standard groove.
