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Discussion Starter · #41 ·
Anywhere between .05 and >.100 off c/b is going to be fine. Your actual coil bind within that set is going to vary anywhere from .010-.020 so fighting for .010-.020" of c/b is really a waste of time. Just keep it under .100 and anything under .05 you're going to want to measure every spring. That's not necessary.
Thanks, I will follow your advice on that. I’m thinking I’ll shoot for 2.02 on the intake and 2.015 on the exhaust, or as close as I can get to that.
I’ve ordered the new retainers and some extra shims, although I have a bunch already. I’ve also ordered a spring rate measuring tool, so that I can see what the difference is without the inner spring.
I’m hoping to have that stuff by Wednesday and then I can start setting it up to see if these springs can work or if I need some other springs.
I also pulled all the springs off one head today and I put one in the vise and measured coil bind and it was right at 1.09” so you’re right about C/B not being as stated by comp (1.13”).
 
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Thanks, I will follow your advice on that. I’m thinking I’ll shoot for 2.02 on the intake and 2.015 on the exhaust, or as close as I can get to that.
I’ve ordered the new retainers and some extra shims, although I have a bunch already. I’ve also ordered a spring rate measuring tool, so that I can see what the difference is without the inner spring.
I’m hoping to have that stuff by Wednesday and then I can start setting it up to see if these springs can work or if I need some other springs.
I also pulled all the springs off one head today and I put one in the vise and measured coil bind and it was right at 1.09” so you’re right about C/B not being as stated by comp (1.13”).
Did you check the coil bind in the vise with a retainer installed?
Some spring companies show a c/b with a safety margin factored in. That's why I always measure.
 

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Discussion Starter · #43 ·
Did you check the coil bind in the vise with a retainer installed?
Some spring companies show a c/b with a safety margin factored in. That's why I always measure.
No sir, I took the retainer off and put the spring by itself in the vise and clamped it until there wasn’t any space left between the coils.
 

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Discussion Starter · #45 ·
Kinda thought so, You have to use the retainer. That inner step compresses the inner spring another .100".
Ah, that makes sense. I’ll try it that way tomorrow. Thanks.
 
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Discussion Starter · #46 · (Edited)
Checked the spring rates on the Comp 948 springs last night, using a cheap, simple, Proform spring tester I ordered from Summit.
Just to get a baseline and to see how close of a reading the tester gave me to Comp’s stated seat pressure of 336# @ 2.10” I.H., I first tested the full triple spring with the retainer installed. At 2.10” it showed 340#, so it seems pretty close to what it should be. In any event, it gave me a baseline.
Motor vehicle Vehicle Gauge Gas Measuring instrument


Gauge Motor vehicle Measuring instrument Speedometer Vehicle


Next, I removed the inner spring and tested it again with the retainer installed at 2.02” and got 300#.
Motor vehicle Gauge Measuring instrument Gas Auto part

So, based on what I’ve learned on this thread, I can use the 948 converted to a double spring, and install it at 2.02-2.03 and that will be better than using it as a full triple spring installed at 2.10.

So far, I’ve installed 4 of the intakes at 2.03”. With the standard locks, there’s plenty of clearance between the rocker body and the retainer:
Fluid Automotive tire Coil spring Hood Gas

BUT, note position of roller tip on exhaust valve…

I haven’t installed the exhaust springs as yet, because after carefully checking the stand heights again, it looks like I will have to use lash caps to get the right rocker geometry on the exhaust rockers, since I can’t get the stand any lower and the rocker tip is too far back on the stem even at the fully closed position. As you can see below, using the T&D #750 checker tool, the tool is showing zero clearance between the rocker shaft and the tool, although I’m supposed to lower the rocker shaft by half the difference between .750 and .816. That’s with the stand sitting directly on the pad, with no shim under it:
Automotive tire Engineering Gas Auto part Machine


So, I threw a .080” lash cap on it, rechecked the clearance and moved the rocker through its full range (closed to .816”) and it looks much better in terms of sweep and position on the valve tip and at mid-lift (measured) the roller tip sits right in the middle of the lash cap.

Exhaust valve half open:
Automotive tire Material property Drill Gas Auto part


Exhaust valve fully open:
Gas Office equipment Machine Electric blue Composite material


Please let me know what you think.

But before anyone says anything about I need to machine the heads or buy new valves, let me say that’s not happening, because one of these heads (which I just got back from Brodix in December) is on the motor already and the valves are brand new Inconel valves that I just bought from Brodix when they reconditioned my heads.

So, on the premise of a man has to do what a man has to do, it looks like I’m going to be running lash caps on the exhaust. The only problem is that I don’t have locks that are recessed for the lash caps (I’m sure I do, somewhere, but can’t find them), so I’ll have to order some from summit. Always fun, these projects…
 
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Discussion Starter · #47 ·
The other thing that I want to mention in here is that it seems that Comp uses the .060” from coil bind rule of thumb as well, at least for computing max lift, based on their published specs.

I say that because based on their specs, the 948 spring has an installed height of 2.10”, coil bind @ 1.13” and a stated maximum lift at .910”

Thus:
2.10 - 1.13 = .97
.97 - .91 = .060

So, by my calculation, 2.03“ I.H. on my intake valves should work (assuming that C/B is 1.13):

2.03 - 1.13 = .90
.90 - .836 = .064
 

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I would advise that you send these photos and script to Sheldon at T&D. They may offer shorter stands. I would call him first, though. Have valve length and as much information on what you have when you do. Are you using Brodix recommended valve lengths?
You are too far to the intake side on the exhaust valve with respect to the roller contacting the valve at full lift by a good bit. Do the intakes look the same?
 

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Discussion Starter · #49 ·
I would advise that you send these photos and script to Sheldon at T&D. They may offer shorter stands. I would call him first, though. Have valve length and as much information on what you have when you do. Are you using Brodix recommended valve lengths?
You are too far to the intake side on the exhaust valve with respect to the roller contacting the valve at full lift by a good bit. Do the intakes look the same?
Thanks.

I'll see if I can reach T&D and see what they say.

The valves are the exact length specified by Brodix for this head, both intakes and exhaust.

The intakes look better than this, although they aren't perfect either. I'm using a .040" shim under the intake stand. The T&D kit only included .080' and .040 shims. Not sure how you're supposed to get it accurate with just those two options...

The roller tip is perfectly centered in the middle of the exhaust valve stem at mid-lift with the lash cap in place, but it does move inboard a bit at max lift (.816"). It's far worse without the lash cap in place though.
 

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Go on the T&D website, look for the installation tech. section, video tech 101 , something like that. There is a video where Dragzine interviewed Sheldon Miller, tech guy at T&D. This article in tech101 shows different scenarios of problems, why, and what to do.
In the T&D catalog, the application charts for Brodix heads, show installation notes, I've noticed Brodix heads requires what I seem to remember was something like "machine work required not normally done at home" or some shit like that. I'll look and see what it says & let you know in a few minutes.
I noticed where you said the other head is already installed, let me make a comment about myself.
I'm kind of a prick, (as I've been told), I will go to whatever lengths needed to make something "exact", even to the point of working myself almost to exhaustion, and pissing people off.. It may have something to do with being of German descent, BUT, I can honestly say, it has served me well so far. "Yes, I worked my ass off for awhile, but now it is exact!". Just saying....
 

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That rocker set doesn't show anything in the footnotes saying machining required not normally done at home.
Using the .750 tool, my figuring, your shaft should be below the tool .043 for the intake and below the shaft .033 for the exhaust. Are you getting this? Either with the lash caps or without?.
 

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The other thing that I want to mention in here is that it seems that Comp uses the .060” from coil bind rule of thumb as well, at least for computing max lift, based on their published specs.

I say that because based on their specs, the 948 spring has an installed height of 2.10”, coil bind @ 1.13” and a stated maximum lift at .910”

Thus:
2.10 - 1.13 = .97
.97 - .91 = .060

So, by my calculation, 2.03“ I.H. on my intake valves should work (assuming that C/B is 1.13):

2.03 - 1.13 = .90
.90 - .836 = .064
Sounds like your close to letting her rip and hopefully not R.I.P :D:p
 

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Discussion Starter · #53 ·
Go on the T&D website, look for the installation tech. section, video tech 101 , something like that. There is a video where Dragzine interviewed Sheldon Miller, tech guy at T&D. This article in tech101 shows different scenarios of problems, why, and what to do.
In the T&D catalog, the application charts for Brodix heads, show installation notes, I've noticed Brodix heads requires what I seem to remember was something like "machine work required not normally done at home" or some shit like that. I'll look and see what it says & let you know in a few minutes.
I noticed where you said the other head is already installed, let me make a comment about myself.
I'm kind of a prick, (as I've been told), I will go to whatever lengths needed to make something "exact", even to the point of working myself almost to exhaustion, and pissing people off.. It may have something to do with being of German descent, BUT, I can honestly say, it has served me well so far. "Yes, I worked my ass off for awhile, but now it is exact!". Just saying....
Thanks man. I have watched that video and read all the documentation I could find on setting the stand height, including stuff relating to Crower and Jesel.
The machine work that was necessary for the T&D rockers was done by Brodix at my request. Apparently all the 3XTRA heads Brodix produced since 2012 came with that machining work, but my heads are circa 2008, so I needed to have it done. Basically, the corners of the spring pads needed to be cut back as shown in the photo below:
Automotive exterior Audio equipment Bumper Gas Auto part


But Brodix certainly knew I was going to use the T&D 3128 rockers, because I literally asked for the necessary machining for those rockers to be done to my heads. They certainly didn’t tell me there would be an issue with those rockers and that length valve, although I’m really not trying to blame them for anything. And I don’t know if the pads can even be machined down without weakening the heads/rocker mount?
A longer valve would solve the problem, but would prefer to change the stand height if that’s possible.
As far as you being a prick, don’t worry, I’m probably far worse, although I admit sometimes my laziness displaces my desire to be meticulous. I get the German thing though. The wife’s one of them and we spend a month or so there every year, so your thinking is probably spot on on that count.;)
God help me…if I have to pull that head back off, I’ll probably sell the whole damn thing.:mad:
 

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Discussion Starter · #54 · (Edited)
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Discussion Starter · #55 ·
That rocker set doesn't show anything in the footnotes saying machining required not normally done at home.
Using the .750 tool, my figuring, your shaft should be below the tool .043 for the intake and below the shaft .033 for the exhaust. Are you getting this? Either with the lash caps or without?.
Your calculations are correct, according to my understanding as well.
Yes, I’m getting close to .043 on the intakes (with the 0.040 shim under the intake stand) and I somehow stupidly forgot to measure the exhaust with the lash cap on. I’ll do that and report back.

That little T&D measuring tool is a PITA to keep in position though.

The Jesel one is nicer and you don’t have to rip a rocker apart to get a shaft to measure off of.
WTF can’t T&D include a dummy shaft like Jesel does with their tool. I like that the Jesel tool goes over the valve stem too. BTW: the Jesel tool can’t work with the T&D rockers, because the shaft on the jesels are smaller in diameter.

BUT, here’s the thing that really got me scratching my head: the Jesel tool instructions say the tool is for valve lifts between .600 and .800”, and if you’re over .800, you should remove .050” of shim?! So, if my cam was .800” lift, I’m good, but if its .816”, it needs to be adjusted down by .050”??? Really? Somethings not right with that…

So, I’m starting to wonder if I’m not being to fussy about the precise height of the stands being absolutely spot on? There’s no way to achieve that anyway, without a million shims, of various thicknesses, instead of a stack of .080 and .040 shims.
 

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Please don't take this comment as arrogant, but you are overthinking this. First of all, you're saying you intakes are real close with the .040 shim. OK, the intakes are DONE and correct. Stop thinking about the Jesel stuff, you got T&D....I'm assuming you have the 1 piece intake stand, right? The exhaust stands are 4 each per head, bolt to the head and have the small bolts that bolt to the intake stand. Is the exhaust shaft lower than the tool, with the lash cap, measure with a feeler gauge. What is the measurement? I know the little flat tool is cumbersome to hold with the lash cap on, but It can be done by holding down somewhat on top of the tool keeping the angle against the side of the lash cap.
I went thru all kinds of bullshit when I converted from rocker studs to shafts on my old GM Bowtie heads, then when those heads destroyed themselves and could not be repaired, I bought Dart 355 cc. bare, and started all over again with a new set of T&D's. Just part of the fun....
Again, shaft below the tool by .043 intake
shaft below the tool by .033 exhaust with the lash cap right now, nothing else matters....
 

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Discussion Starter · #57 · (Edited)
Please don't take this comment as arrogant, but you are overthinking this. First of all, you're saying you intakes are real close with the .040 shim. OK, the intakes are DONE and correct. Stop thinking about the Jesel stuff, you got T&D....I'm assuming you have the 1 piece intake stand, right? The exhaust stands are 4 each per head, bolt to the head and have the small bolts that bolt to the intake stand. Is the exhaust shaft lower than the tool, with the lash cap, measure with a feeler gauge. What is the measurement? I know the little flat tool is cumbersome to hold with the lash cap on, but It can be done by holding down somewhat on top of the tool keeping the angle against the side of the lash cap.
I went thru all kinds of bullshit when I converted from rocker studs to shafts on my old GM Bowtie heads, then when those heads destroyed themselves and could not be repaired, I bought Dart 355 cc. bare, and started all over again with a new set of T&D's. Just part of the fun....
Again, shaft below the tool by .043 intake
shaft below the tool by .033 exhaust with the lash cap right now, nothing else matters....
No worries man. I’m grateful for the assist.
I understand what I need to do.
I just checked the intake again and it’s not .043, and without a different shim set I can’t get to that number. It’s closer to .035” as best I can measure it. That’s with a .040” shim under the intake stand.
On the exhaust without a shim and the lash cap on it, the gap between the tool and the rocker shaft is too big, something like .070. So I stuck a .040 shim under that stand and it’s pretty close to perfect at about .032 - 0.35.
It is a bitch to hold the valve up without a spring on it, whilst keeping the tool square against the valve stem and measuring the gap with a feeler gauge. But it looks like I’m getting there.
Thanks again for your help.
 

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OK, so you're off on the intake by .008, you're good there.....
Now you're off on the exhaust by a whopping nothing.....
Remember to check your stand bolts for proper length, need them as long as you can without bottoming out.
Also, use pipe sealer on your stand bolts, I use Rector Seal 5, available at Home Depot, if you have Home Depot in the Cayman Islands.
The fun will continue with the pushrod length......
 

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Discussion Starter · #59 ·
OK, so you're off on the intake by .008, you're good there.....
Now you're off on the exhaust by a whopping nothing.....
Remember to check your stand bolts for proper length, need them as long as you can without bottoming out.
Also, use pipe sealer on your stand bolts, I use Rector Seal 5, available at Home Depot, if you have Home Depot in the Cayman Islands.
The fun will continue with the pushrod length......
Yep, I’m thinking that’s as close as I can get them. Checked the sweep and that looks decent on both.
The stand bolts are good. The intakes stick slightly into the intake ports and the exhaust stand only has that one 0.040” shim on it, so I’m sure that there’s plenty of engagement.
I was wondering if I should use blue Loctite on the stand bolts, since I noticed that a lot of guys use that for sealing NPT threads on nitrous fittings these days?
I typically use Locktite brand Teflon thread sealer for that kind of thing though. Might just stick with that, if I can’t find the Rector Seal 5 stuff.
We don’t have a Home Depot brand store, but between the various home supply and automotive stores we have here, we pretty much have any sort of product that you can find in the US. What we don’t have, unfortunately, is a decent modern machine shop, IMV.
 
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