Holley Sniper 2GC to 2F Install using Mosley Motors adapter (16 Viewers)

[charliemeyer007]

Cheap and effective is to do a dry then wet compression test on all cylinders. +1 for hearing valves is way better than burning them.

A crack in the dizzy cap can short out one jug, can be very hard to detect. Scrape the contacts inside the dizzy with a knife, small blade on swiss army knife is perfect for the task. Aluminium oxide build up on the post is an insulator. Pull the plug wires from the cap - clean and inspect the inside of the cap and the contact on the wire. Look at the boot end too.

 

[cruisermatt]

Do you hear the two “jumps” in the sound of the compression when it’s cranking? It sounds like you have two cylinders without compression, and a 2F can actually run ok on five cylinders. But four cylinders will be pretty poor. Would also explain by it’s been getting worse out of nowhere.

Hopefully just a blown head gasket between 4/5 or 5/6.

 

[desmocruiser]

Apologies for the dumbA$$ ness but, here is TDC? Correct?

And the clearance can now be checked on these valves? Correct?

 

[charliemeyer007]

If the valves on #1 are both loose its TDC. With dizzy cap off the rotor bug will be pointing towards #4 spark plug.

 

[desmocruiser]

Thanks.

Haven’t pulled the cap again, it is. DUI distributor and I assume the same orientation plus a PIA to get back on.

I stared to doubt myself when the tolerances are too tight for either the appropriate Intake or Exhaust gauges to fit any of the valves that are marked to be adjusted?!?!

 

[charliemeyer007]

I just pull all the plugs, set #1 to tdc - check/adjust. Grab metal fan and pull up watching threw the next in order spark plug hole with a flash light to see the piston come to the top - check and adjust. 1. 5. 3. 6. 2. 4.

 

[cruisermatt]

Thanks.

Haven’t pulled the cap again, it is. DUI distributor and I assume the same orientation plus a PIA to get back on.

I stared to doubt myself when the tolerances are too tight for either the appropriate Intake or Exhaust gauges to fit any of the valves that are marked to be adjusted?!?!

You can be at TDC #1 on either the compression or exhaust stroke. As Charlie said both rockers, and all the others pictured, should have lash (loose) when #1 is at TDC on the compression stroke.
Regardless, I think you're working a bit backkwards and should compression test before going further. Maybe I should have been more explicit in my previous comment about how it sounds during cranking.

 

[zerotreedelta]

Agree, there does seem to be a bit of a gallop while cranking. Curious what both a compression test and the lash show.

 

[desmocruiser]

You can be at TDC #1 on either the compression or exhaust stroke. As Charlie said both rockers, and all the others pictured, should have lash (loose) when #1 is at TDC on the compression stroke.
Regardless, I think you're working a bit backkwards and should compression test before going further. Maybe I should have been more explicit in my previous comment about how it sounds during cranking.

Thanks!

If I am correct and the mark I pictodenotes TDC ( that is where I thought Lash should be measured), there is none. The valves are so tight that a feeler gauge will not fit under the tip of the rocker.

I will test the compression next.

 

[Jdc1]

Thanks!

If I am correct and the mark I pictodenotes TDC ( that is where I thought Lash should be measured), there is none. The valves are so tight that a feeler gauge will not fit under the tip of the rocker.

I will test the compression next.

That might be exhaust TDC- you want to be on Compression stroke. Rotate 180* and see if the pushrods are loose.