Steel Pushrods

[geodoc]

I've installed lash caps on a LM1 to get kind to the rocker faces & to keep the pushrod socket to rocker angular clearance as well as same geometry, the pushrods need to be a bit shorter. The trick seems to find a place that can provide metric spec rather and inch spec ball & socket ends.

Smith Brothers only has inch radius ends, but can provide aluminum rods. Manton can provide metric ends, but can't do it in aluminum, only steel:

http://www.mantonpushrods.com

So I'm thinking that Manton's would be the way to go of course, wanting the ends to fit the lifter and rocker ball. Problem is, if you run steel rods I would assume that you need to run a clearance that's appropriate to it's lower expansion rate, that is different that the stock aluminum clearance.

No experience here, but I seem to remember that some racing guys were (are) running steel pushrods. So what valve clearance do they run?

BTW: the price for Manton pushrods is $8.00 each. Not bad!

[Rosey]

George
I have used steel pushrods made by Raceco (USA) in a LM3 and the instructions say to set the clearance at 2 thou.
Worked well for me for 40,000 kms.
Brett

[geodoc]

Yeah, I'm getting a bit of information from Charley Cole and Guzziology too that say just that ...... .002"

Wonder what one earth would have caused the pushrods to bend in the 1st place. The spring pressure wouldn't seem to be an issue:

~ 105 lb static
~ 245 lb @ full lift

George
I have used steel pushrods made by Raceco (USA) in a LM3 and the instructions say to set the clearance at 2 thou.
Worked well for me for 40,000 kms.
Brett

[pete roper]

We've got ChroMo pushrods in our race bike and use 2 thou cold. Other alternative would be to set 'em hot with the ability to pin the rod but little more1 2 hou cold will cause less pain though. I originally bought the steel rods for my little hot-rod that was running to ten grand so I was running high spring pressures and I was worried about collapsing the alloy rods. Thing is the ChroMo rods are substantially heavier from memory. Unless you're chasing really high RPM I tend to think they are a product whose benefits are offset by their disadvantages. What cam are you running?

Pete

[geodoc]

Heh Pete,

Running a Megacycle 620X10. The valves are black diamond (tips trimmed slightly for the lash caps) and springs are of unknown mfg. from Mike Rich. Rockers are stock.

This bike is strictly a street hot-rod and would not see more than 8000RPM. Main reason for the steel pushrods is that they can be had in a custom length and with metric radius ends.

They are available in .035" wall thickness which would seem adequate, though was planing to consult with Mike Rich on that before ordering a set.

We've got ChroMo pushrods in our race bike and use 2 thou cold. Other alternative would be to set 'em hot with the ability to pin the rod but little more1 2 hou cold will cause less pain though. I originally bought the steel rods for my little hot-rod that was running to ten grand so I was running high spring pressures and I was worried about collapsing the alloy rods. Thing is the ChroMo rods are substantially heavier from memory. Unless you're chasing really high RPM I tend to think they are a product whose benefits are offset by their disadvantages. What cam are you running?

Pete

[rolf j]

We've got ChroMo pushrods in our race bike and use 2 thou cold. Other alternative would be to set 'em hot with the ability to pin the rod but little more1 2 hou cold will cause less pain though. I originally bought the steel rods for my little hot-rod that was running to ten grand so I was running high spring pressures and I was worried about collapsing the alloy rods. Thing is the ChroMo rods are substantially heavier from memory. Unless you're chasing really high RPM I tend to think they are a product whose benefits are offset by their disadvantages. What cam are you running?

Pete

Still perhaps the steel is the way to go? I'm tempted myself even though I haven't had problems so far. The Guzzi crowd doing racing around here seem to have pushrods as a consumable article, a number of them have failed, even with rather mild cams. They seem to work perfectly for a while and then suddenly collapsing at the end, giving a sudden 5mm lash! Often one see a clean compression failure of the aluminium rather than the rods being bent. There is a tendency the guys around here go rather conservative on the lash, 7 to 9 thou. Could this perhaps be reduced even with alu pushrods to save the poor things from hammering?? (but perhaps at the cost of increased risks for the valves?? )

[Guzzistaracing]

I would go for a set of Titanium pushrods if I was racing anything with pushrods. Here is one link, one of several suppliers. Kind of expensive but if you want the best......?

http://www.paeco.com/Titanium%20Products.htm
http://www.paeco.com/Valve%20Train%20Equipment.htm

[geodoc]

a set of 8 arrived today from Manton (enough for 2 bikes with lash caps: .125" shorter effective length). Clearance set to a loose .002".

Fired up one bike with them installed and seems fine. Will test ride Monday (after Vashon Vintage bike bun-toss this Sunday).

They are A LOT heavier than stock. Mike Rich said could get away with .035 wall. Manton suggested .056 & that's what I went with.

8 pushrods: $65.

[rolf j]

a set of 8 arrived today from Manton (enough for 2 bikes with lash caps: .125" shorter effective length). Clearance set to a loose .002".

Fired up one bike with them installed and seems fine. Will test ride Monday (after Vashon Vintage bike bun-toss this Sunday).

They are A LOT heavier than stock. Mike Rich said could get away with .035 wall. Manton suggested .056 & that's what I went with.

8 pushrods: $65.

Very interested in hearing about your experinces.

I had contact with Paeco, got swift response, and will send a sample of my existing alu-rods and place order for a set of the titanium ones for testing. I suppose the 0.002" gap measured cold is the way to go for for titanium rods as well? (SCARY low value!)

rolf j

[geodoc]

Heh Rolf,

When I was ordering I mentioned titanium push rods to the guy at Manton just out of curiosity. He said that they have tried it out, but not satisfied with the reliability. He did say for certain installations where it could work (short lengths perhaps?), they have a certain alloy that seems to work better than others. Apparently an alloy that allows more flex than the more common ones which apparently have little flex and while hard, tend to be somewhat brittle.

Give them a call. Friendly folks.

FWIW, Tom here uses steel pushrods on his Bonneville Trident and spins it up to 9500 RPM with a very wild cam. He mentioned too that they are noticeably heavier than the stock aluminum ones.

GD

a set of 8 arrived today from Manton (enough for 2 bikes with lash caps: .125" shorter effective length). Clearance set to a loose .002".

Fired up one bike with them installed and seems fine. Will test ride Monday (after Vashon Vintage bike bun-toss this Sunday).

They are A LOT heavier than stock. Mike Rich said could get away with .035 wall. Manton suggested .056 & that's what I went with.

8 pushrods: $65.

Very interested in hearing about your experinces.

I had contact with Paeco, got swift response, and will send a sample of my existing alu-rods and place order for a set of the titanium ones for testing. I suppose the 0.002" gap measured cold is the way to go for for titanium rods as well? (SCARY low value!)

rolf j