Just wondering- has anyone added bronze bushings to as set of un-bushed ductile iron W2 rockers? Mostly I'm wondering if there is enough meat in the casting to ream out for bushings or if the bushed and un-bushed castings are different.
Adding Bronze Bushings to Ductile Iron Rockers
- Thread starter JedIEG
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Yup. Gary at Rocker Arm Specialties can do it.
I have no idea now. Used to be under 300 bucks, but I seriously doubt it now. Call him and see. Gary is a super good guy. He can also manipulate the center bore and make them 1.6 ratio if that is of interest as well.
Last set of W2 econo iron rockers I did about 6 months ago was about $16 to $18 as I recall each at Rocker Arm Specialities. They do nice work and can even change the ratio to 1.6 for an extra charge if you want to go that route.
..... because....
Bushings can be had in 1/32 wall so your not going to lose that much strength in the rocker arm and I believe the trade off to be worth it.
Locomotion
Well-Known Member
RAS installs bushings in the rockers using the original bore and adds smaller diameter shafts with thicker walls. I believe they correct the individual ratios in the process and include new 12 point adjusters and hold-downs in their package deal. Bushings are drilled and/or blocked in the rocker as needed for better oiling. OEM 273, Crane, Isky, etc.
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19DART66
Well-Known Member
It has been quite a few years since I ran W2 heads, so the memory has faded since then. But as far as I can remember from having both a set of bushed and non bushed rockers, there were no differences between them other then the bushing. The part of the rockers the shaft went through were a lot thicker and beefier on the W2's then the 273 adjustable rockers.
I imagine the number would be in the millions.......
That is the number of engines of various makes that used ductile iron rockers without being bronze bushed on steel shafts........& provided millions of miles of trouble free service. My Poly engines were among them.....
Post #10 would be the safest way to bush rockers...
That is the number of engines of various makes that used ductile iron rockers without being bronze bushed on steel shafts........& provided millions of miles of trouble free service. My Poly engines were among them.....
Post #10 would be the safest way to bush rockers...
gzig5
Well-Known Member
The bushings are bronze, which is a surprisingly tough and strong metal equal to or exceeding cast iron in some properties. So it's not like you are simply boring a bigger hole and thinning the walls out weakening the system. The bushing has inherent strength as well. As mentioned using smaller diameter shafts is another way to increase strength of the rocker if that is a concern.
Gzig,
Sadly you are not getting it.....& it is pretty simple. For the second [ or third? ] time, when you remove material from an object, you weaken it. The bush in this instance will do NOTHING to compensate for the loss of strength caused by metal removal. The wrap-around area under the shaft is very heavily loaded & rockers that break often break THERE.......and that is where you are weakening the rocker to install a bush.
Sadly you are not getting it.....& it is pretty simple. For the second [ or third? ] time, when you remove material from an object, you weaken it. The bush in this instance will do NOTHING to compensate for the loss of strength caused by metal removal. The wrap-around area under the shaft is very heavily loaded & rockers that break often break THERE.......and that is where you are weakening the rocker to install a bush.
Newbomb Turk
Well-Known Member
What you are missing is that rocker was available bushed. Same rocker for the bushing as for the unbushed econo stuff.
And the bushed rockers are for high rpm, high load stuff.
SSG_Karg
Enhanced member
Just to add to this discussion, here are pictures of said rockers side by side.
W2 Econo on top, W2 bushed bottom
Factory 273 with bushing added by RAS on top, aftermarket 273 (Isky?) unbushed bottom.
W2 Econo on top, W2 bushed bottom
Factory 273 with bushing added by RAS on top, aftermarket 273 (Isky?) unbushed bottom.
You are 100% correct and I agree. However, my friend down under, those millions of engines didn't have squat for spring pressure either. Just something to think about.
Exactly. Plenty of meat for bushings.
I may be mistaken but weren't the original T/A rockers bushed?
autoxcuda
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And still most of the original used ductile rockers you find are scored on the bottom.
Yes sir they are!
19DART66
Well-Known Member
Oh ya, and I ran those weakened fragile bushed W2 rockers for 8 years, shifting at 7500 with 670 lbs spring pressure over the nose and thousands of street miles with 4.89 gears. Must have been real lucky, because not one of them broke. They held up better then the Comp roller lifters link bar that broke and took out the cam, oil pump and bearings. Then there are the 4 Indy rockers non bushed that snapped just driving along at 2500 to 3000 rpm in my current 416 while cruising with 4.10 gears.
SSG_Karg
Enhanced member
I honestly can’t say that I have ever heard of anyone breaking any iron rocker arms.
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