Carb noise at all rpm = intake valve, right?

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Model T Ford Forum: Forum 2016: Carb noise at all rpm = intake valve, right?
Top of pagePrevious messageNext messageBottom of page Link to this message  By Chris Laughary on Thursday, July 07, 2016 - 03:06 pm:

I hear what sounds almost like a cracked exhaust air pressure leak from one cylinder, but it sounds like it is coming out the carb.

When I swap the head I want to check and adjust the valves while it is open. Any videos or list of instructions will be greatly appreciated. I will study all of the materials I have but it is likely that a modern checklist has been made by someone who has done this.

Even a head bolt torque pattern can be improved better than simply saying "start at the middle and work your way out." Middle left or right? 10 lbs per bolt first, then add 10 lbs each round up to 50, then back off to 45? Etc.

Thank You in advance. I will try to post a video of the sound.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Tony Bowker, Ramona, CA on Thursday, July 07, 2016 - 03:17 pm:

Middle center.
The correct sequence is in the MTFCA Engine handbook (and elsewhere).
Torque to 35 and then 55 ( some say 50). Then repeat after a run, at least three times. Again this is all covered in the MTFCA engine handbook.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Royce in Dallas TX on Thursday, July 07, 2016 - 03:19 pm:

If you search the forum there are dozens of discussions about head bolts. If you have ever changed the head gasket on a lawn mower then you know how to do it. Success is dependent on making sure the surfaces are super clean, the gasket is oriented properly, and the bolts are evenly tightened. Too tight and you will strip a bolt or break a bolt. Model T blocks made before 1925 were of questionable quality cast iron. The bolts are pretty good, but not Grade 8 by any means.

Using a torque wrench is not critical, and Ford did not use them originally to assemble the engine, nor did Ford ever state a torque value. Using small increments is not going to make any difference. They just need to be tight. Using a Ford Model T head bolt wrench is a good way to get it right the first time.

You should do a cold cranking pressure test to see which cylinder has a leaky valve. You do that by opening the throttle fully, removing all the spark plugs, and then measure the PSI in each cylinder after turning the engine over the same amount of time for each cylinder.

http://www.mtfca.com/discus/messages/599638/653637.html


Top of pagePrevious messageNext messageBottom of page Link to this message  By Chris Laughary on Thursday, July 07, 2016 - 04:40 pm:

OK, I'm embarrassed that my hearing is so bad. That noise was my coils and can only be heard in the cab.

I'm still looking for my compression test kit


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