• Hi Guest!
    If you appreciate British Car Forum and our 25 years of supporting British car enthusiasts with technical and anicdotal information, collected from our thousands of great members, please support us with a low-cost subscription. You can become a supporting member for less than the dues of most car clubs.
    There are some perks with a member upgrade!
    **Upgrade Now**
    (PS: Subscribers don't see this gawd-aweful banner
Tips
Tips

Engine block modification for oil to water jacket leak

Share this page

J

jcsb

Jedi Trainee
Offline
Has anyone here done the mod where you drill the 2 passages for installing stainless tubes? They note a drill depth with a tolerance of +/-.020" depth. Typically, unless noted in machining terms all drill depths or to full bore depth. Should I assume they mean this or should they have said from drill point?

John
 
John, In the machining world if the prints give a depth tolerance of +- .020 it means from the face of the block to the extreme end of the bore.... The point of the drill, unless otherwise specified.

Now, if your going to bore a hole for a small sleeve, I'm sure they are giving you a proper size drill and reamer to achieve a size on size to - .001 max shrink fit for small bores under one inch.

I always stop short .125 of my depth tolerance, and then grind the face of the reamer flat with a slight relief around the leading edge of the flutes ...then peck in very slowly to my depth tolerance, so the rear of the hole is flat. Be sure to use a set of depth gauges to check the depth as you go. Take your time!

BTW...you can source the drill, reamer and stainless tube at places like Granger and such!
 

Attachments

  • image.jpg
    image.jpg
    195.8 KB · Views: 168
Last edited:
Drambuie,
I should have given a little background. I have been a manufacturing engineer for the last 40+ years. I've either supervised or owned my on machine shop, including for the last 15 years. My shop Merit Machine Inc. had 13 cnc machines, including cnc wire edm, ram edm, deep hole drilling edm, vertical cnc mills, horizontal cnc mills, and numerous cnc lathes. I retired earlier this year. I believe I was pretty specific in noting what was called out by some others who have done this mod. There are no prints. As I noted unless noted all drill depths are to full bore depths when machining. Unfortunately the people writing the modification seemed to be lacking in specifics, so I wondered if anyone else had done this mod and could shed some light on this. If you need to have any work done let me know, even though I sold most of my machines I kept 2 cnc lathes and 2 cnc mills to do some of my fun work. I do appreciate your reply, but really knowledge of machining isn't the problem here.
John
 
Hello John,
Very good meeting you, I too should have given a little more of my background. I too have worked in the mechanical engineering field and Have 29 years experience in both manual and CNC machining,lathes, mills, O.D grinding, Mig welding,mechanical assemble and installation. Most of my work has been Proto type projects, repair, field service and engineering for the Large Web Press industry working with Mitsubishi Heavy Industries, Baker Perkens and others. I too managed the machining operations and eventually partnered with my brother to open a successful Machining service catering to domestic and overseas Printing company's. My brother is still going at it...and I'm retired at 54. I live in Bali Indonesia part time and spend the rest of my time here in the Chicago burbs....but looking to move to a warmer climate such as Florida. Take Care!
 
Drambuie,
Well I believe we have very parallel lives. I live in Houston and Santa Fe New Mexico. Hot and cold. My experience has been a pretty broad swath. I started in military armament, moved to commercial engineering, then industrial engineering, and finally to the energy industry. I've been fortunate to work for some very progressive companies, but of course my bigger success came from the companies I formed. They gave me the life style I so richly deserved (LOL). Nice meeting you too.
John
 
jcsb said:
Drambuie,
Well I believe we have very parallel lives. I live in Houston and Santa Fe New Mexico. Hot and cold. My experience has been a pretty broad swath. I started in military armament, moved to commercial engineering, then industrial engineering, and finally to the energy industry. I've been fortunate to work for some very progressive companies, but of course my bigger success came from the companies I formed. They gave me the life style I so richly deserved (LOL). Nice meeting you too.
John
Click to expand...
. John...I just looked up a great article for you....Look up Technical articles Austin Healey owners club Queensland .....they will tell you everything about the mod there! Great to meet you!
 
Thanks guys. While both seem to be the same neither address where that depth tolerance is taken from (drill tip or full bore). As Drambuie and I are very familiar with machining practices the norm is to full bore depth unless specifically stated drill point. Since there seem to be a concern about intersecting a close feature. So I will consider it full bore but insure the drill point does not proceed past that depth. I will come behind it with a reamer with the relief removed from the end. I'll try and write something up on this to clarify any concerns in the future.
John
 
Back
Top