5.225 is what I believe to be the stock valve length. Can anyone tell me if the valvetrain geometry would be negatively affected by using 4.910 length exhaust valves with stock length intake valves? Thank you
What engine are you needing info on? There were no stock valves at 5.225 length. That is a HotHeads "race" length.
5.225 is the length of the old smaller valves I pulled out of my '55 331 heads. I'm looking at replacing the intake with 2.080, 3x8 stem, 5.225 O/L, .225 tip. I found some exhaust valves that I liked, only the length was 4.910. I looked at the HotHeads valves, but they have 11/32 stem and I don't want to have the change my guides. Can you tell me the stock valve length? Also, would 5.225 work if the were the same in both intake and exhaust?
A 5.225 valve is too long. The stock valves should be approximately 5.050 in length. Any that I have measured have been in that range. When adding that kind of length, the rocker arm is going to be right on the edge of the stem, instead of the center where it belongs. That leads to excessive side loading of the stem and guides. The correct length valves in .375 diameter stem are available. (I dont stock them, but can get them.) I am sure that Gary (QEC) has, or can get them also. Unless you need a different length stem because of cam lift or rocker ratio, there is no need to use a GM valve.
I really don't want to use those if possible. The 2.080 valves I mentioned were Ferrea F1636 340 Mopar. I've found some 2.020, 3/8, 5.050. 225
5.225 sounds too long...are the valves you removed marked? How about a pic? As Tom notes, long valves are not a 'drop-in' and can cause problems if used as is. We have installed long valves and tall springs in the Chrysler heads but in order to maintain correct contact to the rocker tip the rocker ***emblies required alot of work... .
I wont be where I can access the valves for awhile , but the springs were red which I'm pretty sure wasn't stock for '55. I'd like to use stock rockers without any additional "engineering".
Can anyone tell me what the valve stem height sould be ,after grinding the valves? Have seen a castle type sleeve, to place on head with valve in. If the valve stuck above the tool,you ground stem down,if it was below the castle notch.Replace valve.This is a `55 331 hemi.
as noted above the length is critical. you say you don't want to change the guides now. well you will be doing it soon after it is running due to the side load. do it right the first time. its a lot cheaper than doing it twice.
This is a ten+ year old thread but it popped up in my search for info on 392 hemi valve stem lengths. So far from what I’ve read; stock valve stem length is 5.05” and Hot Heads sells a long stem valve that’s 5.22-5.24”. The long stem is to allow for a longer spring for valve lift beyond .550”, lift being limited on old Hemis. Like most rocker shaft engines, longer stems means shimming the rocker stands (or special aftermarket stands) to regain proper rocker arm geometry. Then measuring for longer push rods. Have I got this right? My new valves measured at 5.240 overall length. I’m trying to order valve springs but it seems like I might need to order new stock length valves and the appropriate springs. What say the hemi gurus?
Old posting but there are many options which I use on ***embling cylinder heads.. 4.910” are what SBC’s use and you can purchase .100” longer. If 5.010” work better… why not. They are 11/32” if than makes a difference. If using 10* keepers which can be bought at standard and .050” plus or minus to help control spring pressure and length. Lash caps are also available to get your rocker geometry closer too.
I started this engine build back in the mid to late ‘90s for my Willys pu nostalgia race car. I basically dropped off a good 392 block, crank and heads to Dennis Baldi’s machine shop and asked for a serious blown alcohol combination. He gathered his favorite race parts and did most of the machine work while I made installments and built the car. It sorta stalled when it got to the valve train - Donovan had stopped making his forged rockers and roller rockers were beyond my immediate budget. $1500 for the cam and roller lifters plus $2800 for rocker ***emblies. Ugh. Dennis wanted to retire so I squared up with him and took my parts home. Fast forward 25+ years…. What do I do with this pile o parts? Finish it up, I guess. Apparently, Dennis went with the race valves with the longer stems. So I’m left with a choice: buy new stock length valves and springs and use stock rockers (doesn’t make much sense) or keep the long stem valves, buy springs and get roller rockers with the correct geometry built into the stands. As it often happens with me, writing this stuff out and asking for information/help, I usually answer my own questions. Internet and catalog searches often leave me with more questions than answers. By asking the questions here I know that the answers will come bubbling up out of the quagmire and confirm or deny my su****ions. And it keeps my one-finger typing skills sharp…..
Bob… sounds funny but I use the Compe***ion Products Catalog for all my springs, retainers, and keepers..seals too. After showing all the brand products there is a page of installed height, pressures, and diameter with the part# and manufacturer. They also list steel cup style and inner support style bottoms for aluminum heads. They list conical, beehive, and standard style springs even triples. Over the years I’ve bought name brand from them and others just from the information. The only tools I’ve bought are a valve spring height micrometer and a spring pressure tester you use in a vice. It’s not the perfection of high dollar engine builder but with time and knowledge of how everything works if been happy and successful on how I use the parts and tooling.
I’ve got their catalog, I didn’t think to look there. Thanks. That’s the good ol’ fashioned way of finding race parts, plowing through dimensions and specs to find what works. I guess I’ve fallen into the 1 800 Hot Rod trap over the years, expecting all that detective work to be done for me. In my defense, I have never been an “engine guy”, I’ve always been more of a ch***is/header fabricator type guy who occasionally finds himself having to do an engine, transmission or rear end.
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