Mopar sb 273 rocker arm dual spring question

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Dmopower

Dmopower

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I am changing cams in my 67 273. Swapped out the solid cam and installed a flat hyd. I added small dual springs and guess what. Some of my adj rockers rub the springs. Now I'm sure some of you are giggling by now as I have seen these posts before. Question. Do I grind these rockers for Clerance? or do I buy new rockers and pushrods? This is a cheap get me by engine but it's all new. Are the cheap, dare I say it Chinese roller rockers good enough for a small cammed 273 and will they clear my springs? Any other thoughts, suggestions? Are there special springs for this combo?

Thanks in advance guys.
 
In my opinion it is not a good idea to compromise by grinding the rocker arms. Buying other adjustable rockers, especially aluminum which are thicker will likely also require grinding.

If you can find another reduced diameter spring and retainer package with the right specs to avoid the grinding that would be a better alternative. You could also look to a geometry kit from B3 racing that typically moves the rockers up and back from their current location.
 
Any chance you could post a picture of where they rub? If the springs are the same diameter and the same installed height, i can't see where the interference would come from. Maybe a different retainer or the new cams base circle is a lot shorter?
 
OldmanRick said:
Any chance you could post a picture of where they rub? If the springs are the same diameter and the same installed height, i can't see where the interference would come from. Maybe a different retainer or the new cams base circle is a lot shorter?
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Old springs 1.4" OD New ones 1.5" Im wondering what springs other folks have used to upgrade without grinding. I see they sell 1.437 OD with a 1.08 ID. Does anyone know if that spring will work?
 
Why on earth do you think you need dual springs on a small-cammed 273?
Get a set of 340 springs and call it a day. I've run those springs with those rockers on mild street builds for decades and never had an issue.
 
Professor Fate said:
Why on earth do you think you need dual springs on a small-cammed 273?
Get a set of 340 springs and call it a day. I've run those springs with those rockers on mild street builds for decades and never had an issue.
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I may have said dual springs but I meant single springs with a damper and the 340 springs I bought are too big. 1.494 OD.
 
Dmopower said:
I may have said dual springs but I meant single springs with a damper and the 340 springs I bought are too big. 1.494 OD.
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Beehive springs solved my interference issues with 273, Crane and Harland Sharp rockers. You'll have to do some research to find the right combo of installed height and pressures for your particular combo. In some cases, you can find .050" + or - valve locks to help get the installed height & pressured as needed. But a little grinding for clearance won't cause issues with most single springs.
 
Dmopower said:
I am changing cams in my 67 273. Swapped out the solid cam and installed a flat hyd. I added small dual springs and guess what. Some of my adj rockers rub the springs. Now I'm sure some of you are giggling by now as I have seen these posts before. Question. Do I grind these rockers for Clerance? or do I buy new rockers and pushrods? This is a cheap get me by engine but it's all new. Are the cheap, dare I say it Chinese roller rockers good enough for a small cammed 273 and will they clear my springs? Any other thoughts, suggestions? Are there special springs for this combo?

Thanks in advance guys.
Click to expand...
You already had to by different pushrods to make this work. Right? B3 racing is the ticket. I really don't see a small amount of relieving being a problem.
 
Bodyperson said:
You already had to by different pushrods to make this work. Right? B3 racing is the ticket. I really don't see a small amount of relieving being a problem.
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Yes I bought new pushrods. I looked at the site but did not see where to buy that kit they advertise for the rocker shafts.
 
Dmopower said:
Yes I bought new pushrods. I looked at the site but did not see where to buy that kit they advertise for the rocker shafts.
Click to expand...
All of the kits are custom. Mike sends you the info he needs to get the measurements he needs to correct your geometry.
 
People have clearanced rockers for DECADES. That doesn't necessarily make it right. With low lift like yours, I think it's overkill for the B3 kit, unless you just want it DEAD RIGHT, which it will do. Are you going racing? You gonna do a lot of high RPM operating? If this is just a street cruiser, I'd clearance the rockers in a second and never look back. Is it right? No but it'll work.
 
Never a good idea to remove metal from a part that is stressed. You weaken it, simple as that. Better to buy new springs & BH are the way to go. If you stick with conventional springs, you need to get a set that suit your cam, ie duration & lift, so that the springs are neither too strong or too weak.
 
Dmopower said:
Can you give me an est cost?
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Mine was $200 a few months ago, that was including the offset hold downs. Depending on how much correction is needed you might be able to use the standard hold downs which drops the price a bit.
 
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