Whats with this

[Plymouthy Adams]

see post 16

you can use a dial indicator in conjunction with the degree wheel at number 6 on this engine..but for resetting a mark or pointer..I would not use a coat hanger in the hole..there is not enough accureacy..but for a quick check for general psoition..yeah, you can pull the pin on this grenade

[karl head]

  Fernando Mendes said:

No.According your pic number 38886 the number 1 cylinder is not in compression stroke.It is in exhaust stroke.

I was away for the weekend and just saw your comment. I find it hard to agree as I rolled the engine over by hand and observed the valves opening and closing and and the picture shows the piston at the top of its travel after the intake valve has closed.

Respectfully Karl

[Plymouthy Adams]

Karl..the shadow as seen in the picture of the exhaust valve makes one think that the valve is slightly open at this time...thus the comment

[karl head]

  Tim Adams said:

Karl..the shadow as seen in the picture of the exhaust valve makes one think that the valve is slightly open at this time...thus the comment

I will check tomorrow just to make sure. However I am pretty sure its just a shadow I rolled it over quite a few times watching the valves.

Karl

[Fernando Mendes]

  karl head said:

I was away for the weekend and just saw your comment. I find it hard to agree as I rolled the engine over by hand and observed the valves opening and closing and and the picture shows the piston at the top of its travel after the intake valve has closed.

Respectfully Karl

When(in pic 38886) the #1 piston is arriving at the TDC,the exhaust valve is in the end of the closing,after(almost same time) the intake valve begins to open.

[karl head]

As promised I checked today, mostly to satisfy my own mind, I had forgotten that I put the head on just after taking the picture so I took off the side cover and checked the valve position with regard TDC. both valves are in the fully closed position so I am pretty sure I got it right I looked at the picture myself a dozen time and I will agree that it appears like the valve is open,but its just my shaky hand or poor photo skills. Thanks for all the input its was well received and I will do my best to keep everyone apprised to my progress.

Karl

[Fernando Mendes]

Karl,looking this pic you can know why the first front valve of engine is EXHAUST valve.

[Fernando Mendes]

Karl,another detail you can notice too(with valve side cover withdrew) is when/if the valve is closed you can turn the valve tappet.In six cylinder engine the valves are disposed front to rear in this following manner:Front E I-I E-E I-I E-E I-I E Rear .This is easy to notice looking to the exhaust manifold(4 exits) and intake manifold(3 exits).

[karl head]

Hi Fernando

I noticed in picture 5 that the exhaust valve is open on #2 cyl and #1 is at close to TDC this is the same position as mine. if you look at the picture you just see it at the top of picture. thanks for the info and the pics

Karl

[Fernando Mendes]

Karl,this is a valve timing drawning of my WWII Willys 1942 Jeep.Notice that the intake valve opens 9º before TDC and closes 50º after the bottom.Exhaust valve opens 47º before the bottom and closes 12º after TDC.Let's make a drawning for our pilothouse?

*Always remember:1)piston up:Exhaust or compression stroke,2)piston down:intake or power;)

[Fernando Mendes]

Karl,this drawing(Jeep valve timing) asked our doubt.In your pic nº38886 piston #1 exhaust valve is still opened in TDC.It will go completely closed when the piston begins to drop some(Dodge=???) degrees(Jeep=12º after TDC).Try to turn the valve tappet,when it is still opened,you can not turn.

[Dave72dt]

Karl, as long as you've got the marks on the crankshaft sprocket, and camshhaft sprocket lining up as shown in the manual and a straight line through them and the centers of the crank and cam, you've got the cam timed correctly to the crankshaft. Apparently a mismatch of pulleys and covers in your case so you'll have to move a pointer or make your own TDC mark on the pulley to use for ignition timing. Hope that answers your orignal question for you.

Fernando, because Karls timing cover pointer and the marks on the pulley didn't line up when piston was visually at the top of it's stroke, he needed to know where the TDC mark should be placed for later use as a reference for ignition timing. That's the primary reason that mark is there anyway. It's a commonly used reference point. That's all it is. He could have checked the accuracy of the placement of the TDC mark with the camshaft laying on the bench or in another room. It wouldn't have affected when the piston reached true TDC. For Karls's purposes, he didn't need to know at the time if it was on comperession or exhaust, so whether is was or not is irrelevant. He will need to know later when he installs the distributer.

[karl head]

Again thanks to everyone for tuning in, My only concern now is wither the exhaust valve is sitting proud. I went back through my pics and it appears that this valve is sitting a little high. it is however opening and closing fine I will do a leak down test just to make sure.

[karl head]

So what ya think. # 1 is the one at the back of the picture

Karl

[Plymouthy Adams]

I think you have a valve with a lost of edge metal showing..not a bad thing but looks out of place with the rest as such..but as Fernado says.. I would look to see that at TDC compression that the proper gap exists between the valve stem and the tappet adjuster..

[Fernando Mendes]

Karl.Send to you a timing sprockets pic of my Jeep.I do not have pic of my pilothouse.Read the valve timing.It is a same procedure.

[karl head]

  Tim Adams said:

I think you have a valve with a lost of edge metal showing..not a bad thing but looks out of place with the rest as such..but as Fernado says.. I would look to see that at TDC compression that the proper gap exists between the valve stem and the tappet adjuster..

It was the first thing I checked both valves are closed and I can spin both lifters easily. As for the valves them selves they looked almost new. what I am wondering is if they had been replace by previous owner and not lapped properly. I will do a compression leak down test to be sure its closing correctly and of course adjust the valve clearances when I get her running. Might have to invest in a better camera or better eyes I used to be able to take good pictures...lol

[Fernando Mendes]

  Tim Adams said:

Don is only stating that the TDC mark is the same be it compression or 180 out..the 4 stroke engine takes 720 degrees of rotation per cycle..so anytime the crank is 360 degrees from X mark it will return to same mark one rotation regardless of the stroke you may be on..this is only relevant when setting the distributor to electrically time the firing to the correct stroke..

Tim,120º instead of 180º,no? I am doubt.

[Plymouthy Adams]

Fernado..the engine is timed by a chain and locks the sync of the crank gear to the cam..the ratio is two to one..thus the whole scheme behind the 720 degrees for all four strokes of the piston...in regard to Don's comment and as well my own..the engine if properly timed and the #1 piston is TDC 360 degrees later..you are still back to TDC but the compresson/exhaust stoke flips...so lets just overlook the shadow on the number 1 cylinder and look again at the mechanics...every 360 the piston is at TDC...the 120 degrees you are referring to rotation for the next piston in the firing order to be at it's top dead center (3 x 120 =360 and times two rattions 120 x 6 cylinders is 720 degree..two rotation of the crank..6 cylinders 4 stokes..

in reference to 180 out...the distributor is slot driven..so if you time it on the wrong stroke..it is merely a flip of the drive tang on the lower end of the distributor 180 degrees to put your spark electrically times with the valves which is time to the pistions via the timing chain..

you do not need a degree wheel on these engines stock...you do not need to know the opening and closing and the lift and the overlap and centerline because they are not critical in stock performance...Unless you suspect a poorly reground cam or bad /worn lobe...now if you were building a monster with a huge deep breathing cam..maybe you need to degree it in a bit..and if you get above 260 degrees you will start to lose compression due to overlap..(approx .6 of one ratio) so you best start thinking of boosting your CR so to maintain the proper CR to effectively take advantage of the cam...you can lose up to three CR's or better depending on the cam thus the need to up the CR in the build..

[Don Coatney]

Probably best to not discuss boost (super or turbo) at this time:cool:

[Fernando Mendes]

the 120 degrees you are referring to rotation for the next piston in the firing order to be at it's top dead center (3 x 120 =360 and times two rattions 120 x 6 cylinders is 720 degree..two rotation of the crank..6 cylinders 4 stokes..

Tim,I am not doubt now.Thanks.

[karl head]

Thanks gentlemen for the refresher and the professional quality of your responses.It is a testament to the dept of knowledge and experience on this site and also to the willingness and helpfulness of its members.

[Fernando Mendes]

Karl,see my damper with degrees pic.My engine is a IND251.When you know which correct degree (before or after),I want to know too.Regards.

!''''!''''!''''!''''!''''!''''!

10 DC 10

[NiftyFifty]

Factor settings in one of these old engines means nothing but a start point fern, it's all about where your engine runs best, mines about 5 deg advance, yours might be 2 retarded.... You just can mark 2+ on every engine and say that's peak performance, too many variables on 50 year old engines

[Fernando Mendes]

  4mula-dlx said:

I found the industrial 251's have the wrong pulley for an auto application but also no timing marks . My original flywheel had no markings even after I removed and cleaned up I could find nothing so I did the TDC and made my own mark.

Then,to my case I have to put 2º AFTER(retarded)?