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rockers, OEM - Spitbits change

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Lizzard d id
san jose, CA, USA   USA
In reply to # 1518596 by colodad the valve stem contacts the rocker pad at the side,
Thats not a problem .

In reply to # 1518596 by colodad and some pushrods are slightly leaning.
also not a problem , most all push rod engines have leaning push rods , some very much so .


In reply to # 1518596 by colodad SB needs some side adjustment to align the pads to the VS, and should help with the PR's angle.
I'd run them as is , but if you want to grind off some rocker tip so that they align with the valve tip ...

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colodad Avatar
colodad Silver Member Calvin Williams
Grand Junction, CO, USA   USA
Spitbits asked for some pictures, they didn't know of any physical changes.

Grind off some rocker tip so that they align with the valve tip ?

How about just machine on the side of the rocker to move it in the direction of the pedestal, the valve contact would be more center of the pad ?


Attachments:
cwIMG_4289a Spitbits - OEM rockers.jpg    55.5 KB
cwIMG_4289a Spitbits - OEM rockers.jpg

cwIMG_4327 OEM-rocker.JPG    27 KB
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cwIMG_4328 Spitbits-rocker.JPG    33.3 KB
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clshore Carter Shore
Beverly Hills, FL, USA   USA
Pardon me, but grinding that away will not make a gnat's arse of difference to the contact pattern or proper functioning of the valvetrain.
It will reduce the reciprocating weight by an insignificant amount, that's about it.

I'd be far more concerned with the contact wipe pattern between the rocker pad and the valvestem tip, which if wrong, will result
in damage to the rocker and the valve.

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1964Spitfire Avatar
1964Spitfire Tim P
Santa Clara, CA, USA   USA
Calvin,

You picture is a bit deceiving because the rocker shaft does not appear perfectly horizontal. So I straightened your photo and drew in a few horizontal reference lines.
I don't see a problem with the tips or the drilling of the rocker shaft hole. But the push rod end ball is definitely out of place, closer to the shaft.


Attachments:
Spitbits - OEM rockers.jpg    29.4 KB
Spitbits - OEM rockers.jpg

1964Spitfire Avatar
1964Spitfire Tim P
Santa Clara, CA, USA   USA
I agree with Carter that you should check the wipe pattern. You don't need to do the blue dykem, a smear of grease will work fine. I use the yellow 'gear marking paint' which is really a yellow grease and provides high contrast.

Also measure your rocker pedestals, from the bottom mounting surface to the bottom of the rocker shaft hole. This will insure your rocker shaft is perfectly parallel with the top of the head. I've seen pedestal measurements vary by several thousands, when trying to pick a replacement from the spare parts bin. This will throw off your wipe pattern.


Attachments:
IMG_3354.JPG    49 KB
IMG_3354.JPG

Lizzard d id
san jose, CA, USA   USA
In reply to # 1518699 by colodad Spitbits asked for some pictures, they didn't know of any physical changes.

Grind off some rocker tip so that they align with the valve tip ?

How about just machine on the side of the rocker to move it in the direction of the pedestal, the valve contact would be more center of the pad ?
The tip of the rocker is wider than it needs to be , you can grind away until you get to the point where it contacts the valve stem tip . Once it is cut down in width you can check the contact pattern if you feel the need .

I think maybe you are overdoing the need for the rocker tip to center on the valve stem tip . It can be off to the side as long as no valve stem tip is exposed .
If I needed to adjust I would go at the supports , you can take some off of them and move the rocker sideways that way also .



Edited 1 time(s). Last edit at 2018-03-13 06:24 PM by Lizzard.

Lizzard d id
san jose, CA, USA   USA
In reply to # 1518710 by 1964Spitfire But the push rod end ball is definitely out of place, closer to the shaft.
The results of the lift tests tell a different story . It could be that the original wasn't the best and that the new ones are just a bit better .

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clshore Carter Shore
Beverly Hills, FL, USA   USA
In reply to # 1518720 by 1964Spitfire I agree with Carter that you should check the wipe pattern. You don't need to do the blue dykem, a smear of grease will work fine. I use the yellow 'gear marking paint' which is really a yellow grease and provides high contrast.

Also measure your rocker pedestals, from the bottom mounting surface to the bottom of the rocker shaft hole. This will insure your rocker shaft is perfectly parallel with the top of the head. I've seen pedestal measurements vary by several thousands, when trying to pick a replacement from the spare parts bin. This will throw off your wipe pattern.

Most folks don't even consider that the rocker shaft could be other than parallel with the top of the head.
But once you start building motors to race, checking everything becomes second nature.
It's really easy to cut pedestal shims to address any issues from brass shim stock using sharp shears.
The stud holes don't require any precision (don't forget the lube hole for the rearmost pedestal).

Lizzard d id
san jose, CA, USA   USA
I'd run them as they are , then I'd pull them for a look see down the road a bit . If the rockers have the right lift and cover the valve stem tip and can be adjusted for the needed clearance , I'd run them as is .

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colodad Avatar
colodad Silver Member Calvin Williams
Grand Junction, CO, USA   USA
Ordered 3 more SB rockers to complete the set, all be same lift ratios. SB didn't comment...

Investigating an oil leak last week and installing the rockers I found ped #2 was a few thousands taller.

I also found all were slightly rounded on the btm, #4 was where the oil was seeping from. Sanded them flat, stopped #4's seep problem.

Check the pad/stem contact after the cruise this Saturday.

I like the clean grind you did.

Lizzard d id
san jose, CA, USA   USA
The rocker arm tips are very wide compared to the valve stem tip , I assume they did that to take care of rocker tip to valve stem tip alignment . Grinding the sides of the rocker arm tips to custom fit is not worthless .

clshore Carter Shore
Beverly Hills, FL, USA   USA
In reply to # 1518983 by Lizzard The rocker arm tips are very wide compared to the valve stem tip , I assume they did that to take care of rocker tip to valve stem tip alignment . Grinding the sides of the rocker arm tips to custom fit is not worthless .

What exactly does grinding them accomplish?
Does not alter geometry.
Does not alter the contact pattern.
Does not reduce wear.
Does not increase lift.
Does not make more power.
Does not make them more reliable.

It WILL very slightly reduce the polar inertia of the rockers, and perhaps raise the RPM where float would occur by (guessing) 25 RPM.
And make them 'pretty' to the eye.

Tonyfixit Avatar
Tonyfixit Tony M
Duncan, BC, Canada   CAN
Some owners fit solid spacers, then custom fit/grind the tips to the minimum amount of material.

I can't imagine to the gain in hp but it would be very small.

Whatever rocks your boat.

colodad Avatar
colodad Silver Member Calvin Williams
Grand Junction, CO, USA   USA
more change discovered, nothing a grinder won't correct.

#8 was ok, but #7 is touching, removing the patina, leaving a ring around the push rod.


Attachments:
cwIMG_4487 #7 pushrod, SBits rocker changed position.jpg    24.8 KB
cwIMG_4487 #7 pushrod, SBits rocker changed position.jpg

cwIMG_4488 #8 pushrod, SBits rocker changed position.jpg    38 KB
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cwIMG_4489 #8 pushrod, SBits rocker changed position.jpg    36.8 KB
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Lizzard d id
san jose, CA, USA   USA
In reply to # 1519000 by colodad more change discovered, nothing a grinder won't correct.

#8 was ok, but #7 is touching, removing the patina, leaving a ring around the push rod.
Cool , good catch . Something for others to be on the lookout for when buying / installing those aftermarket rocker arms .

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