Rebuilt Flathead Problems.

[revkev6]

hope you enjoy that weather... I have aunts and uncles talking about the carolinas all the time... but they haven't run from their kids yet lol.

most people recommend you not put the valve gear you have back in. those are 1951-1953 rotator type keepers on the valves. they use a shorter valve spring that has a tendancy to bind up if you run a performance cam... etc. basically they don't make it all the parts for it because they got ditched as soon as you swapped cams. I have no idea how they work with a chevy valve as I haven't ever heard of someone using your combination of parts! what you need to do is grab a set of dividers and check your open and closed spring length. you can then check your spring pressure at the closed length (i used a bathroom scale and a drill press to get an idea) then check for coil bind at your open length.

you have lots of options if that doesn't work out. DO NOT RUN THE MOTOR WITHOUT CHECKING THE SPRINGS!! if you don't have enough pressure the valve will hit the head and pop.

bored and stroked has posted on the HAMB how he does chevy valves.. reds headers sells a kit.

one more question i have is, where did you get the valve springs from?? they don't look like ford units to me. most stock ford springs dont have a pronounced set of coils that are closer together at one end. the lincoln zephyr springs do though.

you may need to pick up some new 49-50 style retainers and some shims depending on what you find when you check the springs.

[zzlegend]

Not to throw out more ideas than you have already gotten, But I have been following this from page one. Just my 2 cents, but do your self a favor and turn that crank gear around. If it gets buggered up during removal, then buy a new one. They aren't that expensive. Plus they are chamfered on the inside for a reason. I just rebuilt my flathead a few months ago. Stock valves, adjustable lifters, Honed and new rings and bearings as it was 60 over from a failed completed past engine builder. New gears, and an Isky cam also. Runs perfect. Your chevy engine builder obviously did not no nuttin about a flathead. A good inspection of the whole thing would be wise in my opinion. But hey, just take your time and sort thru some of the reply's and do it right. Good luck with it.

[flatheadmurre]

Originally Posted by GordonC

A couple of times members here told me I should post my troubles so others could benefit and I'm glad they have helped. Your welcome buzz4041.

flatjack9 I have torches so can and will put heat to it when I go to give it a pull. If that doesn't work I have seen posts of folks giving the gear a good whack between teeth with a sharp chisel and it splits and then can be pulled off. In which case I will get a new one and put it on. Your correct about running an engine before installing but I don't have a test stand. It went from the engine stand to the chassis. In the future I will purchase no engine unless I get to see and hear it run first!

Not a to good idee to take a whack at the crank gear with a chisel...easier to break or damage the cranksnout then you can imagine...seen a few broken off ones during the years.

[GordonC]

revkev6 I very much enjoy the weather here! So do my arthritic knees! The valve springs came out of a flathead that was used as the power unit for a sawmill. I thought it may be a useable engine as it had been inside out of the weather but it turns out someone left water in it and the pan rails on both sides had freeze cracks several inches long. I had 5 flatheads at 1 time and I saved a lot of parts from all of them. All 8ba engines. I have 3 3/4 cranks, rods, pistons, main caps, dist., intakes exhaust manifolds, flywheels, pressure plates, starters and so on... didn't want to get rid of anything until I knew what I needed for the one I was using. All 4 blocks had bad cracks by the way.

zzlegend I pretty much plan on doing as you suggested when I pull the pan. I'll check everything out as much as I can and do what I can to get things straightened out. Thanks!

[pooch]

From REVKEV6

regarding your post about the gears being in relation when spun... I would guess if the gear is chamfered heavily for the crank fillet then it will be too far forward without the chamfer. if the gears are not in line with each other the cam timing will be out of alignment with the gear. JWL talks about checking the cam clearance to the front cover being in the area of .009 max if memory serves. allowing the cam to move forward or back allows the cam to rotate relative to the crank. the same movement would apply to the crank gear. this could advance or retard the cam.

interesting info Even tho this is only the tip of the iceberg on this engine, I think most of us have learned something new already.

I don't have a crank gear in front of me right now, and the pics so far posted are not real square on.....but it looks to me that the keyway is not central to any two teeth, so counting 3 teeth one way and 3 teeth the other way when reversed is not the same .

The keyway could end up anywhere at the back side in relation to a tooth because of the helical cut..

As well as REVKEY6/s info on, if the gear is not seated properly , it will be turned more in relation to where it would sit if it was fully home.

That gear has to come off.

It would be interesting info if one could mark exactly where the cam timing is now with the gear on backwards and what it will be when it is reversed.


Maybe someone could post a pic of two crank gears laid side by side , one up and one down to show relationship of where the keyway is to teeth.

[GordonC]

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flatheadmurre I am going to start with the least damaging way of removing the gear. I'll use a heavy duty puller and put some heat to it and try to persuade it off that way first. I sure don't want a broken crank snout as the 4 inchers seem to be like gold around here. Rare and expensive!

[GordonC]

pooch I plan on pulling the gear if I can. I'd be happy to mark where I think the timing mark should be based on 3 teeth from the keyway, align the cam with the phantom dot I found, then look to see how far off either is from where it should be if I have a dot on the other side. Right now the cam dot doesn't align with anything other than the phantom dot I found which may be one he added? Just fyi the cam gear is pretty much flush with the face of the crank gear. The face of it is not out from the face of the crank gear.

[JSeery]

Originally Posted by pooch

Maybe someone could post a pic of two crank gears laid side by side , one up and one down to show relationship of where the keyway is to teeth.

I did in an earlier post #88.

[Mart]

JSeery: You might be able to help with this:

I looked at the pics posted by JSeery in post 88. I blew them up and studied the relationship between the keyway and the ends of the teeth. I'm 99% sure the relationship is different if viewed from the rear rather than the front.

What I'm saying is that it would be impossible to correctly time the engine if the gear is fitted backwards.

If I had a gear in front of me I could scribe a line through the centre of the gear past the centre of the keyway. I would do this on both sides and look at the relationship between the line and the tooth.

From the pics already posted they look different, but the angle the pics are taken at is not ideal for making an exact judgement.

Can anyone help with that investigation?

Mart.

[Bob C]

Originally Posted by Mart

JSeery: You might be able to help with this:

I looked at the pics posted by JSeery in post 88. I blew them up and studied the relationship between the keyway and the ends of the teeth. I'm 99% sure the relationship is different if viewed from the rear rather than the front.

What I'm saying is that it would be impossible to correctly time the engine if the gear is fitted backwards.

If I had a gear in front of me I could scribe a line through the centre of the gear past the centre of the keyway. I would do this on both sides and look at the relationship between the line and the tooth.

From the pics already posted they look different, but the angle the pics are taken at is not ideal for making an exact judgement.

Can anyone help with that investigation?

Mart.

I agree with Mart. I put a crank gear on a piece of paper and traced the inner bore and keyway with a pencil then marked where the tooth with the mark was on the paper. When I turned the gear over and lined up the keyway the tooth was about half a tooth off.

Bob

[macdonge]

GordonC... It's important to recognize that the crankshaft (drive) and camshaft (driven) gears are helical. The 8BA flatheads had an opposite gear angle than the earlier (e.g. 59A) versions which were designed to thrust the cam into the timing cover. If your gears are indeed reversed, it becomes all the more important to get them off and oriented properly (from both the thrust & timing perspective). And, yes, you'll need to sort out your valve and valve spring setup while at it. Hang in there. All will become clear soon!

[JSeery]

LOL, looks like Bob beat me to it, but mine has a Christmas background! Little difficult to take procession measurements with pencil marks, but it does look off about half a tooth as Bob suggested.

[GordonC]

Guys half a tooth is a hell of lot better than where I am now!

[GOSFAST]

Hi Gordon, I know you've been inundated with help here but I beleive it all helps to a point??

I'm going to put 2 more photos below here with the crank gear on the cranks snout, it may help a bit more still?

The crank gear keyway is in direct line with the #1 throw, the damper keyway is exactly 180* opposite!

Thanks, Gary in N.Y.

P.S. These shots show the location of the crank gear with respect to BOTH keyways, the timing gear one and the damper one. When you do eventually get past this issue and up to straightening out all the valve train components drop me an e-mail!

[George/Maine]

I think you will find the dot on other side.
I posted a pic of the gears and key that was in my motor book, and was brought to my attention is was trans backward.
I may have did the same thing trusting to old book, I also found the firing order was wrong.

Note using this book I think he put the gear on like to pic and It was correct but being 86 degs off. Grinder use the books for the specs.
That's my guess

[JSeery]

Originally Posted by GordonC

Guys half a tooth is a hell of lot better than where I am now!

That is true, but think the question was, is there any difference between the crank gear on correctly and it being on backward. And the answer it does seem be a half a tooth off. If you have ever noticed, when a cam is degreed in, great lengths are gone to to correct what to some may seem like a small degree of error.

[zzlegend]

Originally Posted by JSeery

That is true, but think the question was, is there any difference between the crank gear on correctly and it being on backward. And the answer it does seem be a half a tooth off. If you have ever noticed, when a cam is degreed in, great lengths are gone to to correct what to some may seem like a small degree of error.

X2 Great pictures also JSeery.
After the timing gears are ironed out, I would next question those chevy valves and springs. Keep plugging away Gordon. You will get it.

[Bored&Stroked]

I've pulled quite a few crank gears in the past - have never needed to use heat. As long as you have the right puller - it should come off. BUT - if it is stuck, some heat won't hurt it. Don't 'whack' it to split it . . . that is a great way to ruin the crank.

Thrust doesn't change when you reverse the gear - that is not an issue.

What is an issue is having the timing marks in the correct place and having the gear seated all the way back as it should be. This appears to me to just be a machine shop screw up.

Cam Gear: It only goes on one way (due to bolt pattern) - so there really isn't a mistake to be made on that end of this deal.

[Bored&Stroked]

There is nothing wrong with Chevy valves - they are a bit longer and the reason that I run them is due to the fact that I run very high performance cams - which means the base circle is a lot smaller than a normal setup. So - having longer valves helps take of that slack. Another reason is that I like some of the valve options for chrome stems, performance profiles below the head, materials, etc.. I have my own valve grinder, so I do massage them to achieve the profiles and head thicknesses that I desire. I usually run Manley Pro-Flow valves in most higher-performance engines.

There are other ways to deal with the issue of smaller cam base circles (and too short of valves in a stock valve situation) --> like using lash caps on the stock length valves. Or, running stock lifters and welding up the valve stems (like in the old days).

Regardless - if you're using adjustable lifters, the goal is to NOT have to turn adjustable lifter screws a long ways out (like you would with stock length valves and a high-lift cam). The reason you don't want the adjuster screws all the way out is that there are not enough interference fit threads to hold the adjusters in their original position -- what happens then is that they usually thread back into the adjustable lifter . . . making all sorts of valve noises and low-lift on the associated valves.

I learned all these things the hard way (40 years ago) . . . running a .450 lift cam with stock length 49-53 valves and Johnson lifters - they were always loosening up and I was constantly adjusting them.

Good luck - stick with it and you'll get it sorted out. You have a lot of "cooks in your kitchen" at the moment - hopefully you create a fine flathead meal as a result.

B&S

[zzlegend]

Originally Posted by Bored&Stroked

There is nothing wrong with Chevy valves - they are a bit longer and the reason that I run them is due to the fact that I run very high performance cams - which means the base circle is a lot smaller than a normal setup. So - having longer valves helps take of that slack. Another reason is that I like some of the valve options for chrome stems, performance profiles below the head, materials, etc.. I have my own valve grinder, so I do massage them to achieve the profiles and head thicknesses that I desire. I usually run Manley Pro-Flow valves in most higher-performance engines.

There are other ways to deal with the issue of smaller cam base circles (and too short of valves in a stock valve situation) --> like using lash caps on the stock length valves. Or, running stock lifters and welding up the valve stems (like in the old days).

Regardless - if you're using adjustable lifters, the goal is to NOT have to turn adjustable lifter screws a long ways out (like you would with stock length valves and a high-lift cam). The reason you don't want the adjuster screws all the way out is that there are not enough interference fit threads to hold the adjusters in their original position -- what happens then is that they usually thread back into the adjustable lifter . . . making all sorts of valve noises and low-lift on the associated valves.

I learned all these things the hard way (40 years ago) . . . running a .450 lift cam with stock length 49-53 valves and Johnson lifters - they were always loosening up and I was constantly adjusting them.

Good luck - stick with it and you'll get it sorted out. You have a lot of "cooks in your kitchen" at the moment - hopefully you create a fine flathead meal as a result.

B&S

Yes B&S,,,,,,,,Totally agree with you.
Just to clarify,,,I should have stated, I see nothing wrong with using Chevy valves and quite a few flatheads out there are running them, but I would question the builder that installed them and what, if anything was done to the seats and where the valve springs came from. The crank gear and timing mark problems raise other possible red flags in my opinion.