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Discussion Starter · #1 · (Edited)
Apparently flat tappet hydraulic lifters are no longer made in the US, and I'm not sure if Delphi makes them in their Mexico plant anymore. I've been running Summit brand lifters in a 350 Chevy for 15+ years and many thousands of miles with no issues at all. Not even a tick-tick-tick at cold startup.

So, what's my best source these days for stock small block Chevy lifters?
 

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With the whole covid shortage its hard to get a lot of things off and on depending on supply and If I am correct there is only perhaps one manufacture who makes lifters in the U.S. but maybe two at the most. I know there is only one cam maker left and there is shortages in cam cores as well. All I know is the flat tappet lifters that folks want and recommend is the ones with a special hardened bottom on them and I don't know who makes them and it may be Delphi but I don't think they make stuff in the U.S. as I bought a set of hydraulic OEM roller lifters from summit and they used to be American made and now there made in Mexico. Hopefully with some more info can come in and chime in but be aware there are some lifter brands that say made in the USA but the parts are from Mexico and just assembled here. Same with a lot of other parts.
 

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I don't think they are American made any more but these are the ones many folks recommend for hydraulic stuff on the flat tappet cams since they have a special hardened foot on them. Below is the comp cam ones to which are the same lifters made by the same company from what I have read but I can't confirm it but they are the same exact thing with the hardened foot on the bottom and says made in USA but take that with a grain of salt.


 

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Hardly anything is made in the US. Given the level of automation these days it probably doesn’t matter much in terms of classical factory employment. Those days are far behind us and probably not coming back.

For flat tappet cam longevity the optimal answer is phosphate coated cam and hard faced lifters. But those on the less economically blessed side of the hobby keep buying the lower cost cams and lifters and often suffer the resultant problems.

At the minimum the hard faced lifter on a cast iron blank cam is better than running regular unhardened lifters. The hard face is an old trick that goes back at least to the flat head Ford days. So lifter and lobe wear is noting new.

Another trick is the older grinds which carry very long durations with modest lift. This gets around stiff valve springs by reducing the acceleration loads with long ramps and modest lifts. The problem with cams like this is they tend to have a lot of overlap and late closing intakes. The overlap while aiding exhaust expulsion also throws a lot of unburnt fuel out which increases fuel consumption and air pollution. At the other end of the intake cycle the late closing intake reduces the trapped cylinder pressure which reduces power and increases fuel consumption as well as air pollution.

The classic answer to these problems back in the 1960’s was to increase compression which drove very high octane leaded fuels which aren’t available anymore except at race tracks and some airports. The higher compression ratio drives higher compression pressure which is what actually does the work this is the so called Dynamic Compression Ratio that goes by several names. Science tells us that you don’t want to go under 8:1 dynamic or it costs all manners of performance measures while increasing fuel burn and pollution.

Today the solution to these issues with long winded older cam designs that are less hard on the lobes and lifters is the same as in the 1960’s of get the compression ratio up. So the way to do that is in the build where you want some type of modern chambered head those from the OEM factories being the L31 Vortec from GM, the Ford GT, and the Chrysler Magnum. The OEMs have aluminum versions of these head in their performance stores as well. The aftermarket is riddled with these type head’s in aluminum or iron in affordable imports to out of sight domestics.

Modern heart shaped chambers allow compression into the mid nines with iron and jamming toward eleven with aluminum which pretty much restores the 1960 era compression ratios that these long ramp cams like to have for minimum fuel burn and air pollution against power produced. Now if your going with sequential injection you can go different ways with cam but that’s another long story.

There is a need to get the squish quench down to around .035 to .040 inch as well. The is pretty easy with iron head’s and stock compression height pistons but harder with aluminum as these like the thicker composite head gaskets that are thicker which pushed this clearance wider than optimum. However, aluminum is more forgiving of this than iron so within reason of about .055 aluminum still shows very high detonation resistance.

If you live where E85 is available you can build more aggressively with less prior planning around the concerns of detonation resistance. But keep in mind that alcohol fuels are dryer than petroleum fuels so the top of the cylinders run with less top end lube. To that end a bottle of Marvel Mystery oil of something similar is a good idea with each fill up.

So the best answer to minimize cam costs and retain long flat tappet cam and lifter life is phosphate coated cams and hard faced lifters next best is hard faced lifters on a standard cam blank. This combined with modern head’s will give old time pre-unleaded fuel performance and then some with a carburetor or self-learning TBI fuel injection.

Bogie
 

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I have read that comp cams offered a Nitrided process for flat tappet cams and I don't know if that is what Bogie is talking about but it costs so much that the cam is about the same cost as a hydraulic roller camshaft. I honestly wish you could still use flat tappet cams and not have to worry so much about wiped lobes and lifters and stuff but with demand for flat tappet cams being going away for a long time and the came maker hardly probably gets any profit from them anymore and most likely makes them on the cheap and the same goes with the lifters from what I have read but I might be wrong but just going by some things I have read over the years as its something beyond the oil and some of the other things like Bogie said contribute to them being such a risk when wanting to use one.
 

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Discussion Starter · #9 ·
Bought a flat tappet cam from Mike Jones many years ago. He was adamant about using his lifters, but I had a NOS set of Delphi lifters that he said would work fine.

Bogie -- Who sells phosphate-coated cams and hard-faced lifters?
 
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