Jump to content

2003 Ai 460 exhaust valve gap


Recommended Posts

I had to replace ejector. Now I'm trying to adjust exhaust valve gap. After replacing  the cam and Jake brake assembly. With the spring loaded push rods collapsed each exhaust rocker to  top of yoke is .365 yes. .365 gap... before I do anything help... I'm 5 hours from a mack dealership...

20220209_184958.jpg

Edited by Kellerfarm2
Added picture
Link to comment
Share on other sites

first.... are you starting on #1?  Do you know how to tell if you are on #1?.  I see you are trying to check #4..  A valve adjustment on that engine requires checking the bridge clearence first, then the valves then the engine brake in that order.. one cylinder at a time in the firing order. If that engine has ceramic lifters, you have no room for error.   please read up on how to do it properly..  I see you did a cam replacement, I assume you have a book..  jojo

  • Like 1
Link to comment
Share on other sites

I don't know about ceramic lifters. Other than it was rebuild about years ago.  

Yes picture is of number piston. 

I have not done anything with the exhaust valves yet. 

I was measuring each exhaust rocker clearances. All are very close to the .35 gap... I haven't done anything with bridges yet... I'm just trying to get started... without a f up.

Link to comment
Share on other sites

8 hours ago, Kellerfarm2 said:

I don't know about ceramic lifters. Other than it was rebuild about years ago.  

Yes picture is of number piston. 

I have not done anything with the exhaust valves yet. 

I was measuring each exhaust rocker clearances. All are very close to the .35 gap... I haven't done anything with bridges yet... I'm just trying to get started... without a f up.

Pay ATTENTION TO JOES NEXT POST! 35 on the set!  the set is a way off either your not measuring  right or it was a real bad set to start with Or you have another possible cam issue! ! these are (rarely )that far out most of the time  2 or three thou one way or the other after 2-3 years!  You should be seeing 16 thou +/- 1 or 2 on intake  24 + / - 1 or 2 !  I'll let Joey write the novel !

  • Like 1
  • Haha 1
Link to comment
Share on other sites

If he's measuring between where the master piston is hit , then there's no telling what he's measuring.  The part he has the picture of isn't the valve adjustment. That's where the master piston of the Jake comes out when the Jake itself is activated and gets hit to push the slave piston to bump the valve off the seat.

Link to comment
Share on other sites

That  balled seat with the hex on it is where you adjust the exhaust valve lash. Then the Jake lash is set under the slave piston.  That big gap between the Jake and the domed cap is closed up when the engine is running with the Jake activated.

Link to comment
Share on other sites

(V)  is the valve lash adjustment and the (J)  is where you set the lash for the Jake.  !!! just the adjusting part . The Feeler gauge goes between the rocker arm and valve bridge to set the exhaust valve. On the Jake the feeler goes between where the slave piston contacts the part of the valve train it hits.   That space the picture is focused on (in my opinion) doesn't really mean much , unless updates were ignored or something there is worn excessively. That will seem like a huge gap, but without the engine running and the Jake activated.... it will be.  !!!!! this could be a problem area though if not matched to the new cam or the master piston is peened over from use over the years. I can remember updates on these parts back when these were new.

Screenshot_20220210-150934_2.png

Link to comment
Share on other sites

9 hours ago, Joey Mack said:

ok. when ou said you put a cam in it, I assumed you did the repair, therefore you would have been reading the book for the procedure. OK thats out of the way..  there is a smal inspection cover on the bottom of the flywheel housing.  it may be rectangular with 6 little bolts, or round with 2 bolts. remove it... you will see a pointer cast into the housing. you will see the edge of the flywheel, where the timing marks are stamped in pairs...   1&6.... 2&5.... 3&4..  I will stop here, because I need to know how much you know before I write this book.. It is also good to have the 'Barring tool' to rotate the engine,,  jojo

Sorry I miss stated I didn't replace cam. But removed rocker arms and the shaft that pivot on... the rocker arm assembly.... Jake brake assembly. 

I didn't go that far into the engine...

Link to comment
Share on other sites

I am reluctant to speak harshly, however.. yes..  as you know, one wrong move and the valvetrain rattles.. It's over...  The truth for me is this...  20+ years ago when I was new and ambitious,  I did a cam job on an ASET...  Keep in mind, I had already done a bunch of valve adjustments and E-Tech cam's  prior..... I rolled the engine up on #1...  ran the rack.... cranked it up..  ran like crap and miss fired..  My heart fell into my stomach... I ran the rack starting on #6, not #1..  I went to my boss and told the truth about my F-up...  he said "fix it' and dont do it again...  10 hr's later, I put new lifters in it and it purred like a Dog... A hard lesson, but.....  It helped make me who I am today...   My 2 cent's...  jojo

  • Like 2
Link to comment
Share on other sites

Well he wasn’t so clueless that he decided to come here and ask for help…I’m sure he knows quite a bit of things that would make alot of us look clueless. 

  • Like 1
Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

 Share

  • Recently Browsing   0 members

    • No registered users viewing this page.
×
×
  • Create New...