<VV> Lifter question

[BEllison@bbafiberweb.com]

Original symptons...reason for the teardown...pulls strong to 3k, but no
power after, in any gear.

Well, did you do any diagnosis before tearing down the engine?  That problem
should have been chased down so you know the cause first.
[<Barry>] Tried, but due to my ignorance, I thought the cam was shot. 




Should I be able to push in a lifter plunger with my hand, whether it be a
SBC, or Corvair specific?

Lifters have an internal piston the slides up and down within the body. If
the lifter is filled with oil, the piston will not easily move down into the
body. But if it is only partially filled with oil, then the piston will
collapse easily. Your lifters may not be filled with oil. Use a trigger-type
oil can and fill the lifter with oil from the side hole. Then the piston
should not move down. If it does the lifter may be bad.

[<Barry>] I didn't fill them with oil, but they easily collapse.  I'll test
this.  I fear though, that this is just a "feature" of these lifters.
Especially, since I only have 12-15 tanks of gas on these pistons/rings and
lifters.


Cam is definitely not off a tooth - I can see the 0 on the cam gear, thru
the crank bolt hole.

It's possible that the gear on the crank slipped. Check that the #1 & #2
pistons are exactly at TDC when the timing marks are opposite each other.

[<Barry>] What timing marks?  Before disassembly, the harmonic balancer
showed 0 deg, with pistons at TDC using my thumb first, then I used a small
screw driver just touching the piston head as a 2nd method.

[<Barry>] But, what you're saying is, and I agree, I still haven't compared
the location of the timing marks with the location of TDC.  I think I see
now.  I should have checked the timing mark at the cam/crank gears, with the
piston at TDC. 

OK, if you have an Isky 280 cam, then the lift should be 0.440 inches at the
valves and about 0.280 inches at the lobes.

[<Barry>] Correct, as per your book.  ;)

See my above description. Your description is not correct. Oil to the
pushrod (and rocker box) is metered by a flapper valve, not the spring, etc.



With the rockers still installed, before the heads cam off, I was barely
getting .175 on several of the exhaust.  The instakes seemed okay, but only
around .260.  I did notice, that as I put pressure on the lifter, I could
see them bleed down, rather quickly, on the dial.



Well, first, to make these measurements with the valve springs installed,
you MUST use a fully pumped up lifter or better yet, a solid lifter. You do
not want the lifter collapsing when you are trying to make these
measurements.

[<Barry>] Yes, someone posted recently (maybe fastvair) about making these,
and it went in one ear, out the other. 
Here is what to do now with the heads off. Repeat your lobe lift
measurements (on all lobes). You can use a fully pumped up lifter (see above
for instructions to pump up) and a dial mike. Just look for max lift which
MUST be about .280 inches and MUST ALL be within .005 in. of each other.

Probably the problem  
[<Barry>] Yes, I think I'm getting there. 



I actually intended to bring your book with me today to read thru the lifter
sections, to work for some lunchtime reading, but picked up the wrong one.
Grrrr
 
I do have one question, directly to you...we don't know how to read a table
in the stock or aftermarket cam section,  <mailto:specs@50degrees>
specs@50degrees There are things like "3A-74", "5B-7A" etc in the intake and
exhaust columns.  The one with ramps is not quite as confusing, but I can't
find where these columns are explained anywhere in the book.  Help?
 
As usually, your sharing of knowledge/experience in such verbose, detailed,
and non-condenscending manner is highly appreciated. 



Barry
Just looking for answers. 



Please note: This message may contain information which is privileged and confidential. If you are not the intended recipient, you are hereby notified that any dissemination, distribution or copying of this communication is strictly prohibited. If you have received this communication in error, please notify us immediately by replying to the message and deleting it from your computer.