hg valve timeing

[jdmodelb]

Can anyone tell me if there is an overlap in the valve timeing. I have had the head off and know that all the valves are seating and also checked the best i could to make sure there was no crossover of ex. and intake in the manifold. I get a small amount of intake threw the muffler. Is this normal?

[thecatskinner]

There is no overlap.

Valve timing is as follows (IXB-3):
Intake opens at 5 deg PTDC, closes at 45 deg PLDC
Exhaust opens at 35 deg BLDC and closes at 5 deg PTDC.

Exhaust valve should be closed at the same point that the intake begins to open.  

I doubt the effects of valve overlap were understood when these engines were made.  I would also expect that the effect at 1700 rpm would be negligible.

[Blake Malkamaki]

I doubt the effects of valve overlap were understood when these engines were made. I would also expect that the effect at 1700 rpm would be negligible.

The effects of valve overlap, duration, etc were known at the time. These engines were developed for low speed torque and were tested for many hours on dynomometers and in the field for the best combination of camshafts, compression, carburation, etc. for the job they were to perform.

My grandfather was the one who did it!

[jdmodelb]

is it possible that this small  amount of intake in the ex. is normall?

[thecatskinner]

Blake--as I was writing that I had the thought I might be on thin ice---I am often amazed at what those guys knew that we think we just figured out:o;):D

[Blake Malkamaki]

Yea, I was down your way Catskinner last week. Ann and I went to Gettysburg and the RR Museum in Strasburg. I took my time at the museum and really studied the old locomotives and equipment. I also listened and overheard what other people were saying. It amazed me to hear some of the young parents trying to explain things to their kids - they had no idea most of the time; but it really got me when they talked as if the 1940s and 1950s were ancient history!

[thecatskinner]

It is a bit of a shame how much we are losing.

When my boys were still home we went to the Landis Valley Farm Museum just outside Lancaster.  
I was explaining to my sons what all the things were and how they were used---as the tour went on we had a growing "entourage" following us:o
They were all things I had either used or seen used in my lifetime but most people were without a clue.