230 Engine Tappet/Lifter Bores

[Matt Wilson]

Hi folks,

I've got a 1949 Dodge Power Wagon with a 230 flathead engine. I rebuilt the engine several years ago, but have not driven it more than 7,000 - 8,000 miles since then and in fact, it has been sitting for over 4 years, unused due to other priorities in life.

I am now working to get it back up and running, and as part of that, I removed the head and manifolds. While in there, I discovered that the valve guides are very worn, and I will be replacing those. Back when I rebuilt the engine, the machinist was supposed to replace the guides, but apparently did not, and I apparently did not check them at the time.

Also, while I am in there, I checked the lifter (tappet) bore clearances using a dial indicator, and found that most are between 0.0025" - 0.004". This is way beyond the 0.0000 - 0.001" called for in my manual, even surpassing the wear limit of 0.0015".

So....questions:

1) Since I am halfway there, should I go ahead and replace the tappets with oversized ones? Vintage Power Wagons says they have 0.008" oversize tappets. I know one side effect of loose tappets is low oil pressure, but the oil pressure seems to be pretty decent, even with these loose tappets in place. As best I recall from over 4 years ago, it's usually over 25 psi, even when the engine is warm and idling, and it gets up to 45 psi at higher rpm. However, I am concerned that the tappets and bores won't last as long as they should with these clearances, and over time, as the crank and cam bearings wear, the oil pressure will drop sooner than it should.

2) If I replace the tappets, I will need to ream out the current bores. My engine manual calls for the use of a reamer (probably stepped or piloted reamer) to enlarge the bores, but I don't know where to find one of these of the correct size these days. It was probably a pretty specialized tool that has long since become unavailable, I would imagine. Does anyone have any leads on these? Or any other method for getting the proper size bore to fit the oversize tappets? Other than removing the engine and taking it to a machine shop....

On a related note, the engine has a high-performance camshaft and springs that I purchased from Vintage Power Wagons some 10 years ago. All they can tell me is that it provides "more lift and longer duration" and they said it is "something like a 3/4 or RV cam" which I thought were totally different types of camshafts. The springs they sent to me are longer to provide increase spring force. Bottom line is that I think all of this would place more demand on the tappets and their bores.

I would appreciate any comments and especially a lead on an appropriate reamer.

Thanks!

[greg g]

yea but the original springs were pretty mushyeven new, so the upgraded ones probably ain't much to worry about.

[Rusty O'Toole]

You might want to consult a local auto machine shop, they should be able to help with the lifter bores and valve guides.

In fact if the rest of the engine was done like the valve train you might want to take the engine out and check everything.

[Matt Wilson]

Thanks for the replies, Greg and Rusty.

I was just reminded by someone else that the oil pressure would have nothing to do with the tappet bores, since they are not pressure fed in this engine. I should have thought of that....

Anyway, the machine shop I used came highly recommended by a co-worker who was known for having very high standards, so I am more and more disappointed the more I find wrong with this engine. Fortunately, I checked all of the other dimensions and clearances in this engine myself, just not the valve guide condition, since they were supposed to be new. I did even check the lifter-to-bore clearances, but at the time, I don't think I was able to find oversize lifters. Now Vintage Power Wagons says they have them.

Everything I've read on forums says the valve guides are easy to replace, and there apparently was a hand reamer available to open up the bores to the next size, so I was hoping to be able to do this stuff myself. I really don't want to have to remove the engine to get these things done. I just don't know if I can find the right reamer.

[Frank Elder]

I don't see how you can ream them out without having metal floating around in the oil.........unless you pull the engine and clean it.

[Jim Saraceno]

I'm not sure how you could remove the tappets without removing the camshaft. I'm not sure how you can remove the camshaft without removing the engine.

I'm not sure how you can remove and replace the valve guides without removing the engine, camshaft and tappets.

So... I'm totally confused. What am I missing here.

BTW... I've replaced the valve guides before and I didn't consider it a very easy task when I just had the block on the workbench.

[austinsailor]

My machinist Knurled the guides, then reamed to spec. Kept the lifters, no new guides needed. The engine would have to be cleaned after this as well, though.

As others hinted, you'll probably have to disassemble the motor and clean well regardless.

[Matt Wilson]

Oh, yes, I intend to do a partial disassembly of the engine. I did not mean to imply that I would not do so. And I will have to disassemble enough of it to clean out the metal shavings.

The valve guide replacement should be no problem to perform with the engine in the truck. And I have been confident up to this point that I can remove enough body sheet metal, radiator and other surrounding parts to allow me to remove the camshaft and lifters, but now thinking about it some more, I'm not sure if I would be able to remove the timing cover and camshaft with the engine still in the truck. I can almost swear that I had done it one time before, many years ago, but I will have to look more closely to see if I still think that could be done.

Meanwhile, does anyone have any leads on a tappet bore reamer for this engine? I've been doing quite a bit of looking around on the web, as well as calling local tool suppliers, but so far I've no luck.

[Matt Wilson]

The tappet-to-block clearance stated in my manual makes me wonder. The manual is Army TM 9-1840A/TO 19-75B-15, "Ordnance Maintenance Engine and Clutch" published in 1952. The manual states that clearance for new parts should be 0.0000 - 0.001" with a wear limit of 0.0015". Why would they specify 0.0000" as the lower limit? It would seem to be a bad idea for anyone to set up their tappets with no clearance. Maybe it has to do with the manual's recommended method of measurement (dial indicator)?

Based on a pretty extensive internet search, it seems that for more "modern" engines (including sixes and V8's back to the 1960's), anything less than 0.001" is asking for trouble. The desired clearance for a variety of engines seems to be between 0.001" and 0.0025", depending on who you ask, and depending on whether flat tappets or roller lifters are used. Mind you, this is for lifters with diameters around 0.8" - 0.9", whereas the 230 flathead six tappets are smaller at approx. 0.624" in diameter.

Does anyone have a different manual for this engine with specs for this clearance, and if so, could you post what your manual states?

[Rusty O'Toole]

From the factory shop manual 49-52. This is for the larger Chrysler/DeSoto engine but should apply to your car.

"To remove the valve tappets it is necessary to remove the camshaft and oil pan taking the tappets out through the bottom of the engine.When reaming valve tappet guides, using tool C-265, it is necessary to remove the cylinder head valves and valve springs in order to install the reamer pilot.

If the valve tappet guides are excessively worn the tappets may be removed, the guides reamed and oversize tappets installed. Tappets are available in the following oversizes: .001 .008, .030, and .060."

Looked in 2 books and can't find out how much clearance is recommended between tappet bore and tappet.

[Jim Saraceno]

My '57 manual, which would be a 230, states Radial Clearance for tappets is .0002"-.001". However later it says tappet clearance should not exceed .002" so I'm assuming the first measurement is new and the second is wear tolerance.

Edited January 21, 2012 by Jim Saraceno

[Matt Wilson]

Thanks, guys. Rusty, one of my manuals also calls for the C265 reamer. The other one uses a different part number, but maybe they're the same. I wonder which oversize these reamers for, since there are/were so many different oversize tappets available. Dunno...

As for clearance, Jim's manual provides the third spec I've seen now. I apparently had overlooked that one of my other manuals (from WWII but still Dodge 230 flathead 6) states that it should be 0.0000 - 0.0007". Interesting. And still seems pretty tight to me, compared to what else I've read for other, more "modern" engines. Also, the wear limit in this manual was listed as 0.0025". Not exactly consistent from one manual to the next.

Also worthy of noting is that the WWII manual, as well as an old Motors Manual, both indicate that the reamer stem should be passed through the valve guide, and this serves to keep the reamer properly aligned in the tappet bore (assuming the tappet bore was properly aligned to begin with). I had been wondering how to keep it aligned, even if it is piloted. This makes more sense.

Now if I could just find one of those reamers. Last night I found a couple of websites for companies that sell reamers in 0.0005" increments. If I order oversize tappets, I could measure them to get the exact size and then maybe order a reamer from one of these places, and attach a stem that will go through the valve guide. Attachment of the stem will be critical.

[Jim Saraceno]

I'm still fascinated with the idea of replacing the valve guide with the engine in the car. Assuming you can get the camshaft, and tappets out, what method will you use to drive the old guides out and the new in?

[JBNeal]

I replaced the valve guides in the '49 with the motor in the truck using a procedure I read about in an old shop manual. Each tappet is bottomed out, and using the 5# hammer & a drift with a center pilot that I found at a local heavy equipment repair shop, I could drive the guides into the block until they were almost on top of the tappet. The valve guides are cast, so they can be fractured and knocked out of the way with a cold chisel. The guide can then be driven again; repeating this 3 or 4 times, the old guide is out of the way. Driving the new guide in with the same center pilot drift, they can be set in place per specifications. If the guide is over driven, a prybar seated on the back of the valve chamber can be used to ease the guide back out. This is a tedious process (with #6 akin to a game of Operation up against the firewall), but it can be done. The same old shop manual also had procedures for valve grinding, valve seat facing, and cylinder honing while the block was in the truck, albeit with special tools that I've never seen other than in books.

[Jim Saraceno]

Wow! I'm impressed! I once tried to drive a valve guide out with the engine in the car and did nothing but bung up the inside of the valve guide.

[Jerry Roberts]

Another helpful hint is to put your new valve guides in the freezer to shrink them before installation .

[ptwothree]

just be careful when hammering on these things. I was, and I still managed to fracture an index finger while using my bfh! This happened with the block on an engine stand....

I'm going to use dry ice to shrink the guides and an air hammer to reinstall.

[james curl]

An old trick from the English car people on removing valve guides is to thread the inside of the guide on the end you wish the guide to go and insert a bolt into that end to drive against. Doing so in this manner tends to shrink the out side diameter of the guide, while hammering on the end to force it through tends to swell the guide.

[martybose]

Maybe it's just me, but in my case we left the worn out guides and used screw-in bronze guides. These are the ones where you use a special tap, then screw the bronze material in. It's not a solid guide, more like a Slinky that is screwed into the threads, then set with an expander.

We did my block almost ten years ago, and the guides were nice and tight when I replaced the valves last year.

Marty

[Matt Wilson]

Interesting tips from you guys. I bought a piloted valve guide driver from Goodson tool company (about $20), meant for use with a hammer. The pilot is just a few thousandths smaller than the ID of the guides. Maybe the drift is for the Dodge flathead guides specifically, since it's such a close fit.

I also bought the new guides from NAPA (about $3 each). They have two part numbers, one for the intake, and one for the exhaust, each being pre-reamed to come to the correct size after being installed with the interference fit in the block.

I will keep in mind the idea of tapping some threads into the upper end of each guide and pulling them with a bolt.

I also bought some pre-fit lube from Goodson. That should help when driving the new guides into place.

Also bought an L-head valve spring compressor from them (about $20).

[Jim Saraceno]

I will keep in mind the idea of tapping some threads into the upper end of each guide and pulling them with a bolt.

Unless I missed something the advice was...

An old trick from the English car people on removing valve guides is to thread the inside of the guide on the end you wish the guide to go and insert a bolt into that end to drive against. Doing so in this manner tends to shrink the out side diameter of the guide, while hammering on the end to force it through tends to swell the guide.

I tried tapping them and pulling them up and out but go nowhere with that method.

[james curl]

You do not pull on the bolt, you insert a long punch in the open end and drive against the bolt threaded into the valve guide. I hope that clears up this process.

[Hooligan]

tnks for making clear.  you have been a real help