Quote from: falcongeorge on September 18, 2019, 10:30:47 AM

….and if they are pitted on the water jacket side....

That's the heavy hitter right there.  You can't sonic every single portion of a cylinder.

Its an issue. Depends somewhat on how thick the sonic test shows, and which way the core is shifted too.

Quote from: falcongeorge on September 17, 2019, 09:49:45 AM

Quote from: Falcon67 on September 17, 2019, 09:07:11 AM

I still have a nice 1979 TRW Engine Parts catalog, I'll get some particulars on that L number tonight when I get time.

I was thinking last night about scanning a couple of pages of FE pistons and posting them, kinda help make this the "definitive FE TRW piston post".

Would one of you please post or send me the page showing the L2298 pistons (427 bore, 428 crank)?  I believe it should indicate which heads the pistons will work with.  I had to modify mine to get them to work with CJ heads....

That piston would be in the "Racing Pistons" catalog, not the Main catalog, I'll dig around and see if I can find that catalog.

Ruined I tell you! Maybe it will be for sale cheap less engine though....

https://www.lsfest.com/ls-powered-1966-ford-fairlane/

Just gotta say, its the Camaro hood geegaws that are truly appalling. Cripes, I always thought those were ugly as hell on Camaros, why would you put them on something else?

that brief footage of Graham Hill at around 3:10 to 3:12 has an interesting back story, see how he is waving his hands around with Duckworth on his right, and Chapman on his left? Hill was a fair bit taller than Jim Clark, who the car was built around. He mentions in the book that he spun the 49 in practice first time out because his hand hit his thigh as he was coming out of a corner, and it interfered with him correcting for his slide exiting the corner, and he spun the car. After that, they fitted Grahams car with a slightly smaller steering wheel, so his hands would clear his thighs. That's some really cool footage, probably shot right after he spun the car?

   TRW/Speed Pro pistons  "were" forged from an alloy called MS75. That is a high silicon ( up to 12%) slloy so it is typically a low expansion material. To confuse things even more they did use 2618 (low silicon) alloy in some applications and "tin plated" them for scuff resistance. They obviously ran at greater clearance. Clark - Welliver the actual company that made the pistons , had a limited amount of "cam turn" profiles and a common way to make the piston live was to add clearance. While they were "the industry standard" and most of us used them , they are way outdated compared to modern computer controlled , complex skirt shapes. The "contract was not renewed with C-W and they disappeared for some time. Now back in production , Speed Pro has tried India and Mexico for manufacturing bases. The alloy has changed and the surface texture has also changed possibly due to a material spec change. Pricing has also shot upwards making other aftermarket pistons more attractive.

There were a LOT of problems when they transferred production to India, especially with pin bores being out of square. Although I recently talked to some engine machinists that have told me those issues have been fixed, I wouldn't bother buying the current ones, especially when you can find lots of NOS or lightly used ones that were made before the transfer to India for $100-$250 like I mentioned. If you are going to go out and buy new "TRW" or Speed Pro forged pistons, the price is close enough that you may as well just buy Racetecs.
FWIW, I think modern skinny rings with a napier cut second and the lower oil ring tension that the napier second permits is probably worth a solid 20hp on a 500hp motor, but I don't see that many guys really taking advantage of that on street motors. They will buy modern pistons, but put very little thought into the ring package, and that's where the power can be found. For sure, if you are going to step up to a modern piston design, there is considerable power on the table in the ring package, if you are going to really pursue that.
There are also the Total Seal spacers designed for use in Stock elim motors, so you can conceivably pursue a state of the art ring package with older 5/64 ring groove pistons, but the cost of the ring spacers is such that you just as well pony up for a Ross or RaceTec forging at that point.

Per Falcongeorge - "L" in the catalog meant Forged Racing piston as I recall.  I sold a bunch of those too.  I have a set of 8 new L2249NF-30 popups for a 289/302 build.  ( and maybe someday I'll use them - he said since buying them in 1980). I still have a nice 1979 TRW Engine Parts catalog, I'll get some particulars on that L number tonight when I get time.

some of the cast pistons in my catalog have the L prefix. The most consistant thing I have found is the cast pistons had a C as the first letter of the suffix after the number. The old TRW part numbering system is a little odd, and can be difficult to de-code. For instance, a Ford 400 piston, L2414F is forged, L2414CF is cast. Occasionally, you will also run across a number with an AF suffix, this is mostly on pistons dating back to the late fifties/early sixties, I'm not sure if those were forged or cast, maybe I can read the catalog and figure it out. For example, the piston listed for '61-'65 390s is L2143AF. Of course these haven't been made for decades, so theres probably not much point in calling your local NAPA and giving them that number. I was thinking last night about scanning a couple of pages of FE pistons and posting them, kinda help make this the "definitive FE TRW piston post".

Crap, how do I get myself into these situations, why cant I learn to just KEEP MY BIG MOUTH SHUT! 
OK, this is basically all in reference to the "old days" when all these pistons were made domestically, but under the old system, there were basically two different species of TRW/Sealed Power/Speed Pro forged pistons, there is the "stock replacement line" pretty much direct copies of OEM pistons and were boxed as TRW or Sealed Power, these generally had a slotted oil ring land, were the same weight as the oem piston, oem pin offset,  and were designed to replace an OEM piston. They were listed in the old TRW and Sealed Power catalogs by OEM application, you would look up the year and engine in the TRW/Sealed Power catalog, and they would list all the parts they made for that application across the page, lifters, bearings, pistons, rings, ect. They were available for pretty much any domestic engine, and honestly, if you used them properly, they were a pretty damned good piston for the price. I'd way rather have them than a goddam hyper, that collapses the ring lands at the first hint of detonation, and fails catastrophically when it fails. I still use them a LOT, and often pick them up good used or NOS for around $100-$150 a set for chevies and small block fords, a little more for FE or BB Mopar. When I first started building motors, if you went to a cruise night or a bracket night or street race, that was what would be in about 98% of the motors there.
 There were also the so-called TRW "racing pistons, which were also sold under the old "Speed-Pro" label, and also Manley and Duffys sold pistons based on the same basic forging, but with slightly different machining. In the case of TRW, these were actually listed in a separate "racing pistons" catalog. These pistons were machined for 1/16 rings instead of 5/64, had drilled oil ring lands rather than slotted, centered pins, most numbers also had floating rather than pressed pins and the majority of applications were domed. A lot of these part #'s could even be ordered without ring grooves and an unfinished dome, so hard-core racers could finish them the way they wanted. These pistons were also designed to run at typical "race piston" clearances. Some of them could even be ordered with grooves pre-cut for head-land or dykes rings, and they didn't weigh the same as OEM pistons, so required balancing. They are a COMPLETELY different deal than the OEM replacement pistons, I know, because I made my living selling all this shit in the late seventies/early eighties. These pistons were also only available for a fairly limited range of engines, compression ratios and pin heights, especially if you raced anything other than a chevy. These ran about $100 more than the OEM replacement line, but to give an example, in the early eighties there were only two FE pistons in this line, a std bore 12/1 428 piston, and a +030 12/1 428 piston.  Any other FE? Forget about it, it was get something from the "OEM" line, or Venolia/Arias.
At that time, you didn't have the myriad of different aftermarket piston manufacturers like you do now, and the price leap between a OEM replacement TRW/Sealed Power piston and a true race piston, like a Venolia or Arias was profound, we are talking the difference (in Canada, were I am) between $200-$250, and $700-$800. there were no mid-priced race piston makers like RaceTec, SRP or Ross, there were the OEM replacement pistons, there was the limited range of TRW/Manley/Speed-Pro "race" pistons, mostly for chevies, and there was the custom race piston, like Arias, Venolia or BRC. So most of us learned how to use the OEM replacement pistons in the vast majority of engines we built, and make them work. And we sure as hell didn't do it by doing things like running them at 4 times the recommended wall clearance. But hell, its not my motor, I don't have any skin in the game, so....

https://www.speed-talk.com/forum/viewtopic.php?t=21873