yellow rose
Overnight Sensation
Yes. I don’t think the valve job is right. Can you pull the valves from 1 cylinder so we can look at them??
Hey Cylinder heads guys- advice needed
- Thread starter SSG_Karg
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Yes. I don’t think the valve job is right. Can you pull the valves from 1 cylinder so we can look at them??
SSG_Karg
Enhanced member
No, Ryan suggested that is what I should do and gave me the specs to mill them down to. .375” measured from head bolt surface to top of pad. Both heads measure within .008” of each other.
yellow rose
Overnight Sensation
Hmmm. I think the last set I milled was about 1991ish and I don’t think that’s the measurement I used.
SSG_Karg
Enhanced member
SSG_Karg
Enhanced member
Maybe someone has one that was born with flat pads from the factory that could jump in with a measurement.......
@70aarcuda ?
@70aarcuda ?
yellow rose
Overnight Sensation
First, that wouldn’t be the cutter I’d use. That’s the small cutter body, and I never use those.
Second, if you look at the intake valve job, you can see the seat is damn near touching the seat of what little top cut there is on the exhaust. Hard to see in the pictures what is what in the exhaust seat where it meets the intake seat.
At any rate, look at the top cut. There is NONE where the intake and exhaust meet. That intake valve needs to go down to get the top cut in.
And, IMO, that top cut is too flat and too narrow.
yellow rose
Overnight Sensation
I wouldn’t use the bolt bosses to measure that. They can be any distance from the factory and they got milled later in life to clean them up if they got beat up during use.
gregcon
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Those rocker stands are an excellent part....to use as a guide in making your own. What you need (from what I can see) is a similar set but with the holes drilled in different places. The good news is that should fix your problem...the bad news is I see too many people not wanting to toss the stands and instead implementing any one of 5 different fixes, none of which are a 'no compromise' solution.
yellow rose
Overnight Sensation
I’m lost here. Move what holes? You can’t offset the shafts mush more than .100 or the shaft gets really thin.
PRH
Well-Known Member
This is because the head for the long valves doesn’t just have the stand higher, it also has the saddle centered farther away from the valve tips.
The shaft bolts and valve stems are on converging lines, so as each gets longer, they get closer together.
Moving the shaft away from the tips is to allow(theoretically) the same length rocker to the used for both heads.
That head for the long valves would have the shaft bolt moved slightly away from from the valves, compared to the other one.
what measurement do you need?.....FRom a race set? or Econo set?
yellow rose
Overnight Sensation
PRH
Well-Known Member
The pretty sunk looking exhaust seat “looks to me” like some of MP’s spotty QC to me.
It’s lower than it should be, but I think it came out of the box like that.
In the early 90’s I used a set of the short valve econo’s on an oval track motor.
They were brand new.
I converted it over to 11/32 stem valves, and used .100 long SBC valves(5.010” long).
Bought the T&D single shaft system for them, which for that head have the bolt holes on center, just like stock heads.
Everything fit fine and worked great.
They went on a motor in a limited class with a flat tappet cam and a 2bbl.
The Chevy guys could run iron bow-tie heads.
The motor was built and dynoed, they had it in the car ready to go, and at the last minute the series go cancelled.
These guys were already running in a couple other series, but those series required stock heads.
All I did was update the top end to one of their existing motors to the w2 stuff.
They never got to run it in the car at a race.
It’s lower than it should be, but I think it came out of the box like that.
In the early 90’s I used a set of the short valve econo’s on an oval track motor.
They were brand new.
I converted it over to 11/32 stem valves, and used .100 long SBC valves(5.010” long).
Bought the T&D single shaft system for them, which for that head have the bolt holes on center, just like stock heads.
Everything fit fine and worked great.
They went on a motor in a limited class with a flat tappet cam and a 2bbl.
The Chevy guys could run iron bow-tie heads.
The motor was built and dynoed, they had it in the car ready to go, and at the last minute the series go cancelled.
These guys were already running in a couple other series, but those series required stock heads.
All I did was update the top end to one of their existing motors to the w2 stuff.
They never got to run it in the car at a race.
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PRH
Well-Known Member
Only as much as required to facilitate the use of the same rockers with the tall saddles and long valves.
I’d say however much difference there is between the two milled off stands of the heads in this thread.
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PRH
Well-Known Member
I see something else you should mock up and check before going too much further.
With 1.5 rockers and 3/8” pushrods, the intake pushrods often rub the area by the valve cover rail at high lifts.
If you look and see how the heads are relieved there for the pushrods, you can see that the cut for the exhaust pushrods is cut deeper into the v/c rail than it is for the intakes.
Def don’t bolt the heads down for the last time without checking this.
With 1.5 rockers and 3/8” pushrods, the intake pushrods often rub the area by the valve cover rail at high lifts.
If you look and see how the heads are relieved there for the pushrods, you can see that the cut for the exhaust pushrods is cut deeper into the v/c rail than it is for the intakes.
Def don’t bolt the heads down for the last time without checking this.
PRH
Well-Known Member
Just curious,
Are those MP stands and shafts?
Are the bolt holes drilled off center in them?
Any pics?
(Don’t bother answering that...... I saw the link you posted for the parts)
Edit- after digging around a little, it appears as though the shafts for the econo heads had the mounting holes drilled on center.
The stands and shafts for the “race” heads are drilled offset.
From the 2001 catalog, it appears MP was offering rockers specifically for the Econo heads with on center shafts.
It seems HS has them listed in a similar way.
No mention of offset shafts for rockers that fit econo heads, and specifying .180 offset shafts and stands for the race heads.
Are those MP stands and shafts?
Are the bolt holes drilled off center in them?
Any pics?
(Don’t bother answering that...... I saw the link you posted for the parts)
Edit- after digging around a little, it appears as though the shafts for the econo heads had the mounting holes drilled on center.
The stands and shafts for the “race” heads are drilled offset.
From the 2001 catalog, it appears MP was offering rockers specifically for the Econo heads with on center shafts.
It seems HS has them listed in a similar way.
No mention of offset shafts for rockers that fit econo heads, and specifying .180 offset shafts and stands for the race heads.
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When the pedestals are milled down the intent is to create the same W2 race head flat stand and use the offset drilled shafts and blocks to get the installed height and spring clearance of the race head as well as the better banana grooves, pushrod and rocker nose drilled oiling holes of the offset drilled shafts.
The milling of the econo head pedestals is a fairly common modification but like everything modified it is key to measure everything as is being checked by SSG_Karg in this thread.
The milling of the econo head pedestals is a fairly common modification but like everything modified it is key to measure everything as is being checked by SSG_Karg in this thread.
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PRH
Well-Known Member
When I was doing stage 6 heads pretty regularly, those things had all kinds of factory machining problems.
It wasn’t at all uncommon for there to be a .060” tip height variance between a pair of heads....... as they came, right ootb.
And I don’t necessarily mean between one head vs the other head....... I just mean between the 16 valves.
There could be a .030-.040” variance between the intake valves...... on one head.
There was no rhyme or reason to how deep the seats were.
A set where the tip heights only varied .030” was a rare treat.
From what I’ve heard, W5’s(or what I like to refer to them as......the stage 6 of the SB world) had similar issues.
No reason to assume that same kind of “quality” didn’t find its way into some W2’s........ especially when you’re dealing with 2 different part number heads.
It wasn’t at all uncommon for there to be a .060” tip height variance between a pair of heads....... as they came, right ootb.
And I don’t necessarily mean between one head vs the other head....... I just mean between the 16 valves.
There could be a .030-.040” variance between the intake valves...... on one head.
There was no rhyme or reason to how deep the seats were.
A set where the tip heights only varied .030” was a rare treat.
From what I’ve heard, W5’s(or what I like to refer to them as......the stage 6 of the SB world) had similar issues.
No reason to assume that same kind of “quality” didn’t find its way into some W2’s........ especially when you’re dealing with 2 different part number heads.
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PRH
Well-Known Member
I checked out the link........ looks like “in theory”, based on the difference in bolt hole positions between the two stands after being milled ......... one head would have(could have) used the offset stands, the other the non-offset stands.
No telling exactly how that would make things look without mocking up some parts.
Based on the pics of the two different bolt hole locations in the heads........ the rocker to valve tip relationship “should” be better on one head vs the other using the current parts on hand.
SSG_Karg
Enhanced member
SSG_Karg
Enhanced member
Race set. How about measuring from the “high” head bolt hole to the pad where the blocks bolt on. And some pictures may help things.
SSG_Karg
Enhanced member
What length valves are you using in your W2s? Are they race heads or econos?
Mike mentioned my valves may be about .100 longer than they really need to be.
PRH
Well-Known Member
Perhaps, but I have to believe MP sold piles of their 5.28/5.29 length valves for those heads through the years........ and that people successfully ran them.
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However, taking the whole head situation into account, I’m skeptical about how the 273 rockers are going to end up working out on the exhaust.
“If it were me”, I think I’d call HS and ask them how much longer w2 rockers are compared to rockers for stock heads.
I’d also ask how long the rockers are that they make for Mancini.
There is currently a set of 8 new MP 1.5 W2 exhaust rockers on eBag.
.
However, taking the whole head situation into account, I’m skeptical about how the 273 rockers are going to end up working out on the exhaust.
“If it were me”, I think I’d call HS and ask them how much longer w2 rockers are compared to rockers for stock heads.
I’d also ask how long the rockers are that they make for Mancini.
There is currently a set of 8 new MP 1.5 W2 exhaust rockers on eBag.
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standard LA rocker which fits intake or exhaust VS W2 Exhaust Rocker P4876345......I always thought they were interchangeable....But looking at the picture....the W2 rocker is wider....and longer...
View attachment 1715592614
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