So smith brothers offers harley pushrods in titanium , im going to give them a call and see what the drawbacks would be , wouldnt mind lowering the weight there , motor will spool up faster , well it did when i tested the roller-x lifters that were made of aluminum and coated , that didnet work out to long had issues , took them out, but man you could tell a difference
There is a difference between street performance and racetrack performance, that's for sure.
Just use their standard steel offerings, 7/16" tapered. Weight at that point in the valve train is trumped by rigidity.
isnt titanium rigid , i know there is aluminum ones and im pretty sure titanium is stronger than aluminum? just wondering what drawbacks are on titanium alloy
Do you have a link to these Smith titanium pushrods? I can't find any mention of them on their website, everything I see is chrome moly steel. In fact a google search for Harley titanium pushrods doesn't find anything. Is this perhaps something Smith Bros do as custom one-offs, that they don't advertise?
I'm also struggling to understand how aluminum rocker arms, and/or lighter pushrods will make an engine "spool up" faster. The weight of those components pales in comparison to the force of the valve springs, not to mention the weight of the flywheels, rods, & pistons, and in fact the weight of the bike itself. My understanding of lighted valve train is so that the engine can either use lighter valve springs for less parasitic load on the engine, or be able to achieve a higher RPM before valve float.
-JW
https://www.jimsusa.com/wp-content/uploads/2019/09/2504-IS.pdf (https://www.jimsusa.com/wp-content/uploads/2019/09/2504-IS.pdf)
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:up: Thanks. Lightweight is indeed a big plus for high RPM operation. I ran some aluminum pushrods from Andrews for a while, although for street use I'm sure they were not necessary. One thing for sure, they were noticeable quieter than steel pushrods, which was kind of nice.
-JW
Aluminum, no thanks
Quote from: motorhogman on December 28, 2021, 12:46:50 PMhttps://www.jimsusa.com/wp-content/uploads/2019/09/2504-IS.pdf (https://www.jimsusa.com/wp-content/uploads/2019/09/2504-IS.pdf)
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I've used these before. Kind of nice that you could use the stock pushrod tubes over top of these adjustables.
Quote from: motorhogman on December 28, 2021, 12:46:50 PMhttps://www.jimsusa.com/wp-content/uploads/2019/09/2504-IS.pdf (https://www.jimsusa.com/wp-content/uploads/2019/09/2504-IS.pdf)
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I have these in a Fatso motor I built many moons ago. Never had any problems with them but never seen the need for them either. They're still in the motor that's sitting on the shelf.
I agree. Titanium pushrods are Nascar 9000 RPM stuff. Kinda doubt you see too many street HDs doing that kind of RPM. But if bragging rights are with the coin, then have at it.
-JW
Quote from: JW113 on December 28, 2021, 12:32:27 PMDo you have a link to these Smith titanium pushrods? I can't find any mention of them on their website, everything I see is chrome moly steel. In fact a google search for Harley titanium pushrods doesn't find anything. Is this perhaps something Smith Bros do as custom one-offs, that they don't advertise?
I'm also struggling to understand how aluminum rocker arms, and/or lighter pushrods will make an engine "spool up" faster. The weight of those components pales in comparison to the force of the valve springs, not to mention the weight of the flywheels, rods, & pistons, and in fact the weight of the bike itself. My understanding of lighted valve train is so that the engine can either use lighter valve springs for less parasitic load on the engine, or be able to achieve a higher RPM before valve float.
-JW
so maybe it was the fact that the roller x lifters were like solids almost , that the motor spun up faster thats all i can think of that would cause it, the mechanic even said it spooled up faster , so i always thought it was from the lifters being so light, but maybe not ,
At 6200 valve float is not in view yet
:agree: with properly spec'd spring control.
Quote from: motorhogman on December 28, 2021, 12:46:50 PMhttps://www.jimsusa.com/wp-content/uploads/2019/09/2504-IS.pdf (https://www.jimsusa.com/wp-content/uploads/2019/09/2504-IS.pdf)
?? alloy
Probably nothing wrong with these, but seems silly to buy adjustables, then toss titanium into the mix. Seems like the adjustables would offset any gain with the titanium.
Plain measure to length would make more sense, but I question the need in a 6,000 RPM engine.
Quote from: itsafatboy on December 29, 2021, 10:28:56 PMQuote from: JW113 on December 28, 2021, 12:32:27 PMDo you have a link to these Smith titanium pushrods? I can't find any mention of them on their website, everything I see is chrome moly steel. In fact a google search for Harley titanium pushrods doesn't find anything. Is this perhaps something Smith Bros do as custom one-offs, that they don't advertise?
I'm also struggling to understand how aluminum rocker arms, and/or lighter pushrods will make an engine "spool up" faster. The weight of those components pales in comparison to the force of the valve springs, not to mention the weight of the flywheels, rods, & pistons, and in fact the weight of the bike itself. My understanding of lighted valve train is so that the engine can either use lighter valve springs for less parasitic load on the engine, or be able to achieve a higher RPM before valve float.
-JW
so maybe it was the fact that the roller x lifters were like solids almost , that the motor spun up faster thats all i can think of that would cause it, the mechanic even said it spooled up faster , so i always thought it was from the lifters being so light, but maybe not ,
Was the "mechanic"the same person who sold them to you? :wink:
I don't get it. SO the lighter they are the more it will help in higher than traditional red lines for HD's, but then we up spring pressure to control the valves at these rpm's. So, where does the advantage of the less weight come into play? My concern has always been a stiffer PR to get the lift out of the cam at these higher RPM's.
Quote from: hrdtail78 on January 03, 2022, 09:13:56 AMI don't get it. SO the lighter they are the more it will help in higher than traditional red lines for HD's, but then we up spring pressure to control the valves at these rpm's. So, where does the advantage of the less weight come into play? My concern has always been a stiffer PR to get the lift out of the cam at these higher RPM's.
And if they were so beneficial, people would be lined up to buy them, and make them, which nobody does either.
Jims made TI pushrods years ago, they broke. Not saying that Smiths can't do a better job but I am on the train with why even bother. As Hardtail stated and I agree, I want the most stout pushrod I can get that does not flex under what are some very extreme pressures and sprung weight for a hydraulic roller cam valve train. Rigidity is job #1 to control the valves. Lighter weight springs and valves are where to trim and then the need for the killer spring pressure goes down. Stress on the weak link, the lifters is reduced.
Quote from: PoorUB on January 02, 2022, 08:00:54 PMQuote from: motorhogman on December 28, 2021, 12:46:50 PMhttps://www.jimsusa.com/wp-content/uploads/2019/09/2504-IS.pdf (https://www.jimsusa.com/wp-content/uploads/2019/09/2504-IS.pdf)
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Probably nothing wrong with these, but seems silly to buy adjustables, then toss titanium into the mix. Seems like the adjustables would offset any gain with the titanium.
This was what JIMS advertised. That you could have adjustables, with about the same weight of solids.
Smith brothers does not make them for harley i was mistaken, i read the message wrong, so just going to use the smith brother .135 quick install, thanks ,
the engine maybe spun faster because the roller x lifters were pretty much like a light solid lifter , not sure but took them out full floating roller just didnt trust them,
Quote from: PoorUB on January 02, 2022, 08:00:54 PMQuote from: motorhogman on December 28, 2021, 12:46:50 PMhttps://www.jimsusa.com/wp-content/uploads/2019/09/2504-IS.pdf (https://www.jimsusa.com/wp-content/uploads/2019/09/2504-IS.pdf)
?? alloy
Probably nothing wrong with these, but seems silly to buy adjustables, then toss titanium into the mix. Seems like the adjustables would offset any gain with the titanium.
Plain measure to length would make more sense, but I question the need in a 6,000 RPM engine.
I had some Jesel solids made to length for one of my engines. 6oz a piece. In comparison. Smith brother adjustable are 4.5 oz.
That was a long time ago. Some snake oil lifters I remember. All the folks that ran them any length of time had failures. Ceramic if I remember.
Quote from: hrdtail78 on January 03, 2022, 09:13:56 AMI don't get it. SO the lighter they are the more it will help in higher than traditional red lines for HD's, but then we up spring pressure to control the valves at these rpm's. So, where does the advantage of the less weight come into play? My concern has always been a stiffer PR to get the lift out of the cam at these higher RPM's.
This is where titanium comes up short. While it may be stronger than chrome moly it's more flexible. So unless you want your pushrod to act like a pole vaulter they're really not a good choice.