Indexing adjustable cam gear

[Dudeland]

On 3/31/2023 at 7:51 PM, Mikesmalaga72 said:

 Ireland eng instructions wont download or send copy if you have them. Thanks!

You can, you just need to put them in your basket and check them out. 

 

 

[Markster]

On 4/5/2023 at 12:37 PM, Son of Marty said:

John, did you pull the head due to a blown headgasket? If not I would assume a light skim to true everything and if thats the case your timing should be fine. Changing cam timing on our sohc engines your going to move the power up or down  but by shifting to gain top end will weaken the bottom end and visa versa.

Hi SOM - so I am sure my head is machined and I have an IE 292cam.  I did not index as discussed above. My idle is rough until I warm up to running temp.  My compression is at 150.  I have blowby too.  Are these symptoms of the mechanical timing being retardant?  Get the adjuster and hope for best?  Compression goes higher if pistons /rings/bore is good?

 

mark

[Schnellvintage]

Blow by is caused by worn or not seated rings.  Compression also depends on rings and cam timing.  Yor might be able to snatch a little more compression with better cam timing. A rebuilt engine I completed had average 170psi with 10:1 and 292 IE cam.  The test was performed at normal operating temp, with throttle plates, 38 degas carb, open. Only 15 miles on engine.

 

Fwiw

Matt

[Son of Marty]

36 minutes ago, Markster said:

Hi SOM - so I am sure my head is machined and I have an IE 292cam.  I did not index as discussed above. My idle is rough until I warm up to running temp.

The fact that your idle smooths out at running temp kinda takes the cam timing out of the question, it comes down to ignition timing and carb settings, but anything you do when cold it will not idle like a new efi car, sorry.

[Markster]

33 minutes ago, Schnellvintage said:

Blow by is caused by worn or not seated rings.  Compression also depends on rings and cam timing.  Yor might be able to snatch a little more compression with better cam timing. A rebuilt engine I completed had average 170psi with 10:1 and 292 IE cam.  The test was performed at normal operating temp, with throttle plates, 38 degas carb, open. Only 15 miles on engine.

 

Fwiw

Matt

Ok so this helps.  I am thinking it is another project for the winter.  I need to fully check all dims on the 1mm overbore and the rings and the pistons. And re-index.  
 

my third time in taking this Frankenstein engine apart. 
 

do I get a badge after three attempts?  I read a few articles on rebuilding the m10 but none said to check the index.  
 

that’s my excuse anyway 
 

I really do enjoy this!

[jimk]

All engines have blowby, it depends on how much to say the engine is worn out.  Blowby can't be stopped, gas leaks past the ring gap.

[Markster]

9 minutes ago, jimk said:

All engines have blowby, it depends on how much to say the engine is worn out.  Blowby can't be stopped, gas leaks past the ring gap.

Indeed. I am familiar with labyrinth seals. I am the Jamoke that cut the rings too. It was my first m10 rebuild.  
 

[Markster]

Ok I am getting ready to put in the adjustable cam gear from Irelang Engineering. That’s not a typo either.  

 

so one last check I did was vacuum at idle hot.  I was looking for the vacuum gage to confirm my suspicions.  I hooked up to the booster.  
 

123 distributor. 
 

head milled not sure how much!

 

292 cam, 38/38 Weber.  
 

 

 

 

Is my cam timing the issue?  Crazy.  

 

 

 

 

[Cabbage Fumes]

I hear it rains a lot in Irelang.

[Markster]

Ok enough screwing around. I need some help. 

[Markster]

Oh heck let’s add to the mix.  It’s an ie 292 cam.  Bought it back in 2015. 

[tme]

9 hours ago, Markster said:

Ok I am getting ready to put in the adjustable cam gear from Irelang Engineering. That’s not a typo either.  

 

so one last check I did was vacuum at idle hot.  I was looking for the vacuum gage to confirm my suspicions.  I hooked up to the booster.  
 

123 distributor. 
 

head milled not sure how much!

 

292 cam, 38/38 Weber.  
 

 

 

 

Is my cam timing the issue?  Crazy.  

 

 

 

 

You might want to start a new topic rather than posting under a thread already marked "Solved".  More likely to catch the eyes of the more experienced guys who have already commented on the original topic.

 

I think it is highly unlikely that the cam is causing the vacuum gauge to jump around like that.  I would be looking for vacuum leaks and adjusting the valves.  But first you might want to connect your gauge to a different vacuum source other than the booster port - think carb base or where the distributor vacuum advance connects.  I'm pretty sure the booster port has you looking at a single intake runner.  The net is full of instructions on reading a vacuum gauge that should give you other ideas.

 

[uai]

If the lift on intake / exhaust is the same just set it on same lift at overlap to compensate for the shaved head.
No real alchemy needed for a street engine with a 292

[John76]

14 hours ago, Markster said:

Ok enough screwing around. I need some help. 

Mark,

The hose on your vacuum gauge is too big, which causes the jumpy needle.

Use a restrictor bushing or a smaller hose (or both) to calm it down.

John

[Markster]

John!  That’s helpful.  I moved this question to a new thread. It’s called “using vacuum gauge to diagnose problems” let’s continue there!  Thanks again!