Intake Valve not seating

[bmwillia]

I am getting good compression on all cylinders but #8(30lbs). I pulled the head and intake and can see that the intake valve is not seating. I put a light in the intake hole and can see light around the edges of the valve in the closed position. Can anyone tell me how I should proceed with fixing this issue?

[corvette8n]

You will have to pull the retainer and remove the valve it may be bent, if not clean and lube the guide/ valve.

[Bob C]

Do you have any clearance between the valve stem and lifter??

[bmwillia]

I have removed the valve and cleaned it. I haven't put a feeler on it yet. I'll try to do that this afternoon.

[bmwillia]

I think maybe the valve is bent.





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[Kurt in NJ]

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Looks to me like possibly lifter broke, crank it around so it moves up and look closer

[Will D]

Originally Posted by Kurt in NJ

Looks to me like possibly lifter broke, crank it around so it moves up and look closer

I second that. If you zoom in, looks like a crack on the lifter.

[marko39]

It also looks like the valve guide halves are not even. Should be able to find a used valve,guide and lifter to replace what's there. Lap the valve and grind the stem to set clearance. If clearance is too much get a longer valve. Keep it simple. Mark

[bmwillia]

The valve halves are ok. They are uneven in the picture because the clip isn't in holding them together. Just using the guide here to line up the valve stem.

I'll take another look at the lifter, but I have turned the engine over a few times and didn't notice any problems with it all together other than the valve not seating. Would a broke lifter keep the valve from seating properly?

Should the valve head be angled slightly? This one is, which is why I thought it may be bent.

Thanks!

[jayvee34]

If it is sitting at a angle, its bent.

[bmwillia]

The lifter is ok. The line you see is from the casting I assume.

I'm going to pull a different valve and check it in the same hole and see if it fits any better.

[bmwillia]

Swapped the valve, and it seated right up.

Where should I order a new valve from? Mac Vanpelt?

[Phil Gillespie]

Originally Posted by bmwillia

Swapped the valve, and it seated right up.

Where should I order a new valve from? Mac Vanpelt?

I would go with him or 3rd generation whoever maybe closest to you.
Reason valve bent?
Good that you found the problem.
Phil NZ

[VeryTangled]

Originally Posted by bmwillia

...Where should I order a new valve from? Mac Vanpelt?

An excellent selection.

'Barn'ers decided to create a couple of threads on the topic. See below.

https://www.fordbarn.com/forum/showthread.php?t=269580

https://www.fordbarn.com/forum/showt...1339&showall=1

[Terry,OH]

You may think of replacing the guide also. remove the lifter and look closely for a crack in the top angled side.

[aussie merc]

valves dont just bend find the cause or you will go through all this drama again Next time it could be catastrophic

[bmwillia]

I don’t know the history of this engine. I believe it was a rebuild but I’m not sure who did it or the level of quality of their work.

What should I look for? What would cause a bent valve?


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[aussie merc]

i'ld re check that lifter it shore looks to be split to me also check the head above the valve for any signs of impact

[Tim Ayers]

Originally Posted by bmwillia

The lifter is ok. The line you see is from the casting I assume.

I'm going to pull a different valve and check it in the same hole and see if it fits any better.

I don't believe the Ford style lifters are cast. Judging from the pictures, that lifter certainly looks cracked to me.

[chap52]

While it open I would replace the complete lifter, valve, guide, clip, etc.. Lap it in, set it to specs and reassemble. You have apparently identified the issue and a little overkill on the fix may save you time and money down the road.
All you who have done a repair "half way" and had to go in and do it again raise your hand... If the second repair was three times as expensive and more time consuming than the first raise your hand.
Just saying, "enjoy the adventure"... Chap

[bmwillia]

I have looked at the lifter pretty close but have not pulled it. All of my lifters have that line on them in that location and I even see it in pictures of new ones on the internet.

Looking at my picture I posted I can see where it looks cracked, but it doesn't really look like that with the valve removed. I'll get a picture of the bare lifter and post it later today.

I'm not opposed to pulling it, although I've never done it and don't know how yet to do it. I didn't know how to pull the valve either until a few days ago.

I really appreciate all of the input and I am by no means arguing with you all. I'm just trying to learn as much as I can.

Here is a picture of a new one from the internet that has the same line I see on mine.

[Tim Ayers]

Originally Posted by bmwillia

I have looked at the lifter pretty close but have not pulled it. All of my lifters have that line on them in that location and I even see it in pictures of new ones on the internet.

Looking at my picture I posted I can see where it looks cracked, but it doesn't really look like that with the valve removed. I'll get a picture of the bare lifter and post it later today.

I'm not opposed to pulling it, although I've never done it and don't know how yet to do it. I didn't know how to pull the valve either until a few days ago.

I really appreciate all of the input and I am by no means arguing with you all. I'm just trying to learn as much as I can.

If you have the valve assembly out, it literally will lift out of the bore. You can use a magnet to pull it out.

Here is a picture of a new one from the internet that has the same line I see on mine.

Ah, I hope Cam Grinder Pete joins in on this. He's said many times that the reason why Ford changed to the solid sided hollow lifter is because that style of lifter was prone to cracking or the top caving in.

[tubman]

I'd clap for your suggestion, but I have both hands in the air.

[bmwillia]

Here are some pictures of the lifter.






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[Tim Ayers]

Originally Posted by bmwillia

Here are some pictures of the lifter.






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Check that off the list. Looks good.

[Karl Wolf]

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I may have missed this idea in the thread, but...
Using a compression tester that is too long,
The valve may hit the end of the tester, and bend the valve.
I've a vague memory of someone bending all of them...
NOT me

Karl

[Tim Ayers]

I just went back a re-read the post. So swapping out the valve fixed the problem, correct?

[bmwillia]

I pulled the intake valve on #7 and inserted it with both the #8 and #7 guides and it appeared to seat and lined up with much better clearance than the original #8 valve (that appears to be bent) using either guide.

I was not able to perform a compression test obviously since the head is off so I won't really know how well it seals until I'm able to do that. I can only say that I do not see a gap between the valve and block as I did with the original valve.

As info, I ordered a new valve and guide from Vanpelt this morning.

Brad

[Phil Gillespie]

Originally Posted by bmwillia

I pulled the intake valve on #7 and inserted it with both the #8 and #7 guides and it appeared to seat and lined up with much better clearance than the original #8 valve (that appears to be bent) using either guide.

I was not able to perform a compression test obviously since the head is off so I won't really know how well it seals until I'm able to do that. I can only say that I do not see a gap between the valve and block as I did with the original valve.

As info, I ordered a new valve and guide from Vanpelt this morning.

Brad

Pour a little fuel around the valve to seat area. It will give you an idea how good a seal you may have with the exchanged valve to seat tightness.
Phil NZ

[bmwillia]

Thanks Phil.

For the bad valve I put a light in the intake hole behind the valve and could see light around the edges. With the straight valve I don't see light. I suppose liquid would be a better test.

[Terry,OH]

Could lap the valve and see the contact area.

[russcc]

he bent valve story. Back in history I ran a rebuilt ¾ race flathead in a ’40. I bought the short block from a friend who had it in his barn for storage. Put it together and installed if. It ran good, but a friend could beat the ’40 in his father’s Chrysler station wagon. That would never do, so I took to very experienced mechanic to check it out. He found one bent valve, and checked the rest of valve train. We figured the valve got bent moving the engine around in the barn. Put it back together and stayed up most of the night getting the valves adjusted. The clearance kept changing as we adjusted one valve and moved on to another. Reground cam flex. Around daylight we pulled out of the gas station and that ’40 pulled like train of mules. The station wagon was no match for it now. We used Jenny Royal gas at the time as it was high octane. and smelled great when it burned.

[Bored&Stroked]

Originally Posted by Terry,OH

Could lap the valve and see the contact area.

That is what I'd do.

Also, the chances that a new valve is going to magically have the correct length are kind of slim. On these engines, the valve stems have to be ground to set the valve lash - you can't just drop in a new one.

Sometimes you need to shorten the valve (grind the stem tip), other times you need to lengthen the valve by welding material on the end and then grinding it back to set the clearance. This takes a valve machine and the ability to determine the valve length requirements (a special mic).

Make sure you understand all of this - and measure the lash with the lifter on the heel of the cam. The lash should be somewhere close to .016 or so.

[dmar836]

I liked the way Mart did it on one of his builds. Can't remember which video it was.
D

[bmwillia]

Mac Vanpelt has a guide on his site for grinding valves here:

http://www.vanpeltsales.com/FH_web/f...cationpg-1.htm

Since I don't have a valve grinding machine, how should I go about lashing in the valve?

Brad

[Bored&Stroked]

If it is too long, then it needs to have the stem shortened on a valve grinding machine. If you have a good depth mic, you should be able to determine how much needs to be ground off the stem - such that you have about .015 clearance.

You'll need to pull the lifter out and put the valve and guide in - then measure the height of the valve to the deck surface. Then, put the lifter back in and measure how much the valve sticks up (from the deck surface). Then subtract the lower number from the higher number, then subtract another .015 and that is the amount that needs to be ground off the stem. You'll need a machine shop to do the work - and make sure you take a pair of dial calipers to measure the total length of the valve and give them the NEW length they need to grind too.

Note: You must FIRST ensure that the lifter is on the HEAL of the cam!

Hopefully I'm making some sense here . . .

[bmwillia]

I think I'm following you. Thanks for the information.

[HD Rider]

I first with the lifter removed I installed the valve and guide and lapped the valve. Be sure to absolutely clean any lapping compound without washing any down into the engine.
Next I installed the lifter, valve and guide, and measured clearance with a feeler. I had .006" on my new valve so I knew I needed to shorten the valve .010.
For me the nearest valve grinding machine is 75 miles away so I went for a drive. I had the machinist grind .010 off the stem. Reinstalled the assembly and checked again.
Mines running great again.

[Don T]

An alternate backwoods method of setting valve lash; I am not suggesting it is a good idea but it does work. I did my 8BA's this way, a real long day to do a complete engine; ton of time and patience. The set-up uses a valve guide to square up to the face of the grinder, takes seconds to take couple thou off the stem with the grinder running. Stop at 2-3 thou short of planned cut and the rest is done by hand. Hold emery paper against the stone and rock the stone back and forth by hand while rotating the valve with the other hand. Use progressively finer papers and lubricants; the last I used was about 800 and wd40 as a lube. Do at least the last couple thou entirely by hand, slow but it is too easy to take too much off with the grinder turned on. Not perfect but within a thou when installed. The stem has a decent polish when done as 2nd pic shows.

[bmwillia]

I have the new valve inserted and lapped. I have .011 of clearance and according to Mac VanPelt's chart referenced above, I should be safe to grind the 8N valve being that 5x and 2N are open at the moment.

I'll try to find a machine shop near by that can grind the valve but I may have to resort to Don T's method to get it up to .015 of clearance.

Brad

[bmwillia]

I just read that clearance for intake valves is .012. If that is the case then I should be able to use Don T's manual method to take .001 off to get to the .012.

So should I be at .012 or .015?

[Bored&Stroked]

Truth be told, won't matter one bit whether you're at .012 or .015. If I was you and you're sure the lifter is on the base of the cam . . . and I had .012 clearance, I'd put it back together and be done with it.

I've never had a case where my valve clearance got tighter over time . . . they always seem to increase, so you should be good to go.

[aussie merc]

so the intake clearance is less than exhaust due to the difference in operating temps when engine is actually running exhaust will be hotter so they expand more so in theory both clearances wind up the same [perfect world] Valve clearance will decrease especially on exhaust valves Not due to valve growth but to seat recession this takes time and is often caused by high temps. bad fuel. and cheap valves [ask anyone with a C15 cat engine what happened when they took the Sulphur out of diesel fuel ]

[Mart]

If this is a 59A motor the clearance for an inlet valve should be .010" to .012" So at .011" you are RIGHT ON THE MONEY.

Only the later 8BA types with the rotator valves got the bigger clearances.

Mart.

[Tinker]

I know the time is pasted for suggesting a good used mushroom valve from folks here that pull them and throw them in a reuse bucket. Fixed my 36 burnt valve for 15$ that way. Lapped and go.

[48-710]

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Aussie merc, being a auto machinist i'm hearing ya mate.

[bmwillia]

Originally Posted by Tinker

I know the time is pasted for suggesting a good used mushroom valve from folks here that pull them and throw them in a reuse bucket. Fixed my 36 burnt valve for 15$ that way. Lapped and go.

The valve I ordered from Mac Vanpelt cost around $15. So I’m right there with you in terms of cost and it looks like a lap and go here too!

Going to attempt to get it buttoned up and running today. I’ll update this post if I do.


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[Bored&Stroked]

What condition is the valve seat in? Have you cleaned it and can you post a picture? If the seat is in bad shape due to a bent valve beating on it in a strange manner, lapping won't resolve the issue. But it will tell you a lot! I'd use fine lapping compound . . . it should be all that you need.

Given that your year engine will have hard seats, the seat may be in good shape - but it is worth checking into. Valve lapping is not regrinding the seat - it is only done to deal with very small imperfections and to validate that you have a good concentric seat, that it is at the right place on the valve and that it actually will seal.

[bmwillia]

The seat appeared to be in good shape. I didn't see your post until after it was all buttoned up so I didn't get any pictures.

When I lapped the valve in, I got a nice even surface on the valve and seat. There didn't appear to be any damage to the seat.

Once I buttoned it up I got 70lbs on the compression test.

I have read that compression on these early engines should be in the 70-100lb range. Is that correct?

All other cylinders are 80lbs.

[aussie merc]

so what caused the valve to bend

[bmwillia]

It may have been bent when it was installed. I don't know but I don't see any evidence that it was hitting anything to make it bend.