Who makes/sells the best adjustable tappets?

[Manxnorton]

Originally Posted by rotorwrench

Too short a deck as above or valves too deep in the pockets due to wear or too much grinding without replacing seats. A tenth is a lot. Grinding the cam may help but dimensions need to be checked. It may need work on several places to get it usable.

As everything ran smoothly in the past I guess that the valve seats cannot be bad. See photos. If I put in te valves without camshaft installed the valves sit 1 mm (0.04") above the surface. That looks ok for me. What do you think?

When I install the camshaft, tappets etc. the valves sit 0.08" above the surface.

How about the dimension of my tappets? Is 62.97 mm = 2.5“ length ok (when screwed all the way down)?

[Manxnorton]

Originally Posted by nkaminar

Best is subjective. One person's best is not another person's best. And Pete is right that it depends on the cam and what the person who made the cam recommends.

I bought the single lock tappets from Snyders, link below, and are very happy with them. I also got new springs, modern valves, etc. from them. Everything fit perfectly into my Burtz engine. I am using the Burtz cam. I set the clearance according to Terry's instructions. The bosses for the tappets were not machined so I had to do the "rule by 9" method but I cheated and adjusted one tappet while measuring the opposite and went back and forth, reducing the time in half. (Measure 1 while adjusting 8, then adjust 1 while measuring 8, etc.) Diameter is 1.110.

https://www.snydersantiqueauto.com/p...htm?pid=978796

I took over the car from my father about one year ago. He had it since the 1990s. I never heard that something was done with the camshaft. I can only guess that it is in original condition. If you could provide me with dimension I could double-check.


Can you tell me the length of the Snyders tappets? If these are shorter than mine, this would definitively solve the issue.

[nkaminar]

I cannot tell you the length of the tappets without taking my engine back apart. However you can email Snyders and ask them. They are very responsive and helpful. Try [email protected] and if she cannot help she will forward your email to someone who can help. One problem may be that they are temporally out of stock so you may have to wait for an answer.

One other thing to measure is the length of the valves. Some modern valves are from a modern engine and cut down to fit the Model A. You may want to ask Snyders what the length of their valve are and compare that to what you have.

[Manxnorton]

Thank you once more for your support.

I realized already that the tappets are not available at Snyders. Same situation with other shops.

But I found somebody on Ebay (see attachment).
I have sent him a question concernig the lenght. They are made by Colony and I hope they fit...

[GRutter]

I would be suspicious of those tappets.
I have a set of Colony single lock tappets purchased from Snyders and I just measured. They appear to be 2.285 fully closed. (Disclaimer: I did not fully close - I measured the length of the tappet 2.255 + thickness of the bolt head .030)
What was the length of your old tappets for comparison with your new ones?

[GRutter]

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Originally Posted by Manxnorton

Thank you once more for your support.

I realized already that the tappets are not available at Snyders. Same situation with other shops.

But I found somebody on Ebay (see attachment).
I have sent him a question concernig the lenght. They are made by Colony and I hope they fit...

Those ebay tappets are 0.015 oversized

[Benson]

I have a set of self locking tappets I got from Berts a couple of years ago.


As I remember they were Colony but not for sure.


They are no longer in their packaging.


I can check with Steve on Tuesday as to whether they might be Colony tappets.


These measure 2.478 when "cranked" all the way down.


BTW the heel diameter is 1.122

[katy]

thickness of the bolt head .030

That's an awful thin bolt head, did you mean .300?

[Manxnorton]

Originally Posted by GRutter

I would be suspicious of those tappets.
I have a set of Colony single lock tappets purchased from Snyders and I just measured. They appear to be 2.285 fully closed. (Disclaimer: I did not fully close - I measured the length of the tappet 2.255 + thickness of the bolt head .030)
What was the length of your old tappets for comparison with your new ones?

Mine are 2.5" long.
If your bolt heads are actually 0.03" this leads to 2.285". That would be perfect.
But if your bolt heads should be 0.3" this leads to 2.555. That is even longer than mine.

[Manxnorton]

Originally Posted by Benson

I have a set of self locking tappets I got from Berts a couple of years ago.

As I remember they were Colony but not for sure.

They are no longer in their packaging.

I can check with Steve on Tuesday as to whether they might be Colony tappets.

These are same tappets used in Bert's rebuilt engines so I am 99 % sure they are Colony.

These measure 2.478 when "cranked" all the way down.

BTW the heel diameter is 1.122

This length is almost the same as mine. That does not help.

[Manxnorton]

Originally Posted by GRutter

Those ebay tappets are 0.015 oversized

Thank you for the hint. That might be the reason why those seem to be the only ones currently available.

[nkaminar]

On the engine I am currently working on the tappets are 2.42, valves are 5.92 and base circle diameter of the camshaft is 0.85. As one might expect the valves vary a bit. The tappets are not all the way down. The cam was reground and I was surprised to find that the base circle varies too. The whole stackup length is about 8.76. If you have the same diameter base circle your total stackup would be 8.64. So it comes down to what is the diameter of your cam base circle?

My tappets are most of the way down. I am decking the block and will have to re cut the valve seats and grind the valves so I may be in the same boat and have to regrind the valve stems a bit.

[rotorwrench]

It seems I remember that the valves from the early GM 305 V6 could be used in the model A but it's been a while so I can't back that up. I would compare all the old stack up parts to the new to see whats different. Most like the double lock Colony tappets. A lot of stuff has been out of stock lately.

[Dave in MN]

Originally Posted by Manxnorton

This length is almost the same as mine. That does not help.

I run into the same situation you are describing a few times each year. The very simple solution is to shorten the valve stems. Shorten them all to the minimum shortest length you need, in other words, don't shorten them more than you need to but keep them all the same length for ease of assembly.
Engine rebuilding shops will have the necessary equipment. The cut edge needs to be precise so don't try to grind them with your bench grinder.

I have a Sunnen machine in my shop....

Good Day!

[Manxnorton]

Originally Posted by nkaminar

On the engine I am currently working on the tappets are 2.42, valves are 5.92 and base circle diameter of the camshaft is 0.85. As one might expect the valves vary a bit. The tappets are not all the way down. The cam was reground and I was surprised to find that the base circle varies too. The whole stackup length is about 8.76. If you have the same diameter base circle your total stackup would be 8.64. So it comes down to what is the diameter of your cam base circle?

My tappets are most of the way down. I am decking the block and will have to re cut the valve seats and grind the valves so I may be in the same boat and have to regrind the valve stems a bit.

Thank you for all the information and calculations. I have checked the dimensions in my case:
Tappets: 2.48
Valves: 5.73
Base circle: 0.95
Total stackup: 8.69

As already mentioned there are about 0.08 to 0.1 which I need to gain. I think that is too much to grind it off the cams. Takes too much time and is too expensive.

I think for me the best option is to have ground 0.1 off the valve stems. You do not see a problem with shortening the valve stems? There is enough hardness 0.1" below the surface?

However, because of your information I see another option: Your tappets are not all the way down and they are 0.06 shorter than mine. With these tappets my issue would most likely be solved. Which tappet type are these?

[Manxnorton]

Originally Posted by Dave in MN

I run into the same situation you are describing a few times each year. The very simple solution is to shorten the valve stems. Shorten them all to the minimum shortest length you need, in other words, don't shorten them more than you need to but keep them all the same length for ease of assembly.
Engine rebuilding shops will have the necessary equipment. The cut edge needs to be precise so don't try to grind them with your bench grinder.

I have a Sunnen machine in my shop....

Good Day!

Thank you. That is what I am most likely going to do.

[Manxnorton]

Originally Posted by rotorwrench

It seems I remember that the valves from the early GM 305 V6 could be used in the model A but it's been a while so I can't back that up. I would compare all the old stack up parts to the new to see whats different. Most like the double lock Colony tappets. A lot of stuff has been out of stock lately.

I did this comparison. The new valves are a bit longer than the old ones. That means no chance to install them without modification.

Same with the tappets: Screwed all the way down they are a bit longer than the old ones.

That finally means shortening the valve stems is the easiest way to solve the issue. Shorter tappets migth be nicer. But currently nothing seems to be available. And I would like to get my car back on the road asap.

[nkaminar]

All these parts came out of the engine I am rebuilding so I don't have any history or information on who make the parts. About a year ago I tried to contact the engine builder in California but got no response. It looks like the engine was rebuilt several years ago. I think your best bet is shortening the stems. I think I may have to do that too.

[rotorwrench]

Some folks indicate that the adjustable tappets of one type or another have difficulty in adjustment when the tappet is all the way down on the heel of the cam. Some have to turn the engine to get the tappet high enough out of the bore to be able to make an adjustment. It seems there is always a trade off when changing parts for a different design.

Special tools were used by rebuilders back in the day to be able to measure the needed valve stem dimension when using non adjustables. This way they could adjust the stem length once then reinstall the valve one time. The old tulip type valves and two piece guides were a PITA to adjust if a person didn't have those tools. I have a set for V8 types but not for the model A engine. I'd need a guide pilot to make mine work for an A or B engine.

[Chris Haynes]

Originally Posted by Manxnorton

I checked this dimension and it is 11.50". There is nothing wrong.

Could your valve seats been ground too deep?