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they have been surfaced, new cast iron valve guides have been installed and 2.000 intake valves have been installed. They said they had to surface just minimal, because the head have been nearly perfectly straight.
at first, i wanted not to touch the old valve guides, but the shop said for the machining of the valve seats, they had no guide for the machining tool which fits right in the valve guides, because they have been worn out too much for the guide.
here are some pictures:
I guess, now its time for a little bowl blending on the intake valves. My thinking is just to smooth the edge under the valves out a bit, since i dont want nothing too fancy (like other perfect hand ported bowls ive seen in this forum, which is always very impressive to see), because its just a nice weather street car.
Im just thinking about making a clip out of iron to "fill" the center exhaust port divider. No filling of the heat riser with molten aluminium, just because im afraid of cracks in the head casting and i like to drive the car on cold autumn days
Heres a picture of the short block, 455 oil pan, new cloyes timing chain and timing cover + water pump is already installed. Its a slow-going project because i have not that much time at the moment, but some process is going on
Nice work. That lip near the fresh valve seat is why most guys get the machine shop to use a cutter under the valve to remove that lip. It means less hand blending, be careful near the valve seat. If the guides were worn as you stated, good idea to replace them. Were the exhaust guides done or just the intake side? Glad to see it going together.
Yeah, i red about that its possible to open the bowls with a cutter. I decided to blend the bowls by myself and think it went well.
Now, i have a few questions about valve spring installed height. The springs im going to (re)use are Lunati 73126 (chart says103 lbs. Seat load @ 1.800 installed height).
These springs were installed in the heads as i purchased the engine.
I ran them with my Lunati cam (Advertised Duration (Int/Exh): 272/276 ;Duration @ .050 (Int/Exh): 217/221 ;Gross Valve Lift (Int/Exh): .485/.485 ;LSA/ICL: 10/104 ;Valve Lash (Int/Exh): Hyd/Hyd ;RPM Range: Idle-5500) the whole last year without problems. My cam card suggests different springs than these, but i have called lunati then, and they said that it will work fine.
these springs are listed with 1.800 installed height. before i had the new 2.000 intake valves and new exhaust valves installed, they were installed with 1.500 OD 0.030 shims under them.
now, with the new valves, i measured the distance between spring pocket and spring retainer for installed height with a digital caliper and a small straight edge as accurate i can, and i found that all the new exhaust valves measurings are approximately .010 over 1.800, and all of the new intake valves are slightly under 1.800.
I would like to have the intake valve measuring a bit over 1.800 too, because i want to install shims under them to save the heads from chewing of the damper spring and if i would install even a .015 shim on the intake valves, it would be out of the installed height tolerance of lunati claimed +/- 0.020.
i guess i will get the machine shop to work the intake valves slightly deeper in the seats to get closer to the exhaust valves installed height measurings to make shimming possible.
what i found too is, that 1.500 OD shims are slightly too wide for the (original) spring pockets of the 7a heads. It seems like they are lying on the corner chamfer of the spring pockets. The 1.500 OD springs are lying flat in there. Is it ok to use for example 1.480 OD shims with 1.500 OD springs?
Sorry for the long text, I hope I was able to explain my thoughts understandable😃
#1 Check the valve spring pressure to at what height they are 103#. They may have lost some tension since they were new.
#2 Mount the shim on something to hold it grind a radius or champfer on the edge thats causing interference. Grind just enough for them to sit flat in the pocket.
I would not have them sink the valves any more. Depending on what rockers you are using there are valve locks that will give you an additional .050 hgt and then you can shim accordingly. Personally I would not worry about it much. Those springs dont have a lot of pressure anyway and .020 or so less hgt wont hurt a thing.
Your method of checking hgt might not be that accurate either. Try the method in my picture below. Cut a piece of coat hanger wire a little long and then grind the end a bit at a time until you can just squeeze it under the retainer. Then measure your wire with the calipers. Make sure it is straight in line with the valve. This method works great on stock heads with small springs where you cannot get a hgt mike in to measure.
Make sure you pull up on the retainer to seat it real good on the keepers. Either that or what I usually do is let it drop down to the valve guide and smack it lightly with a small hammer. You will be amazed at how much hgt you will gain just seating the locks.
#1 Check the valve spring pressure to at what height they are 103#. They may have lost some tension since they were new.
#2 Mount the shim on something to hold it grind a radius or champfer on the edge thats causing interference. Grind just enough for them to sit flat in the pocket.
thanks for the help!
#1: today i checked all springs on a drill press with a precicion parcel scale like ive seen in a youtube video. Adjusted 1.800 on a caliper and compressed the springs on the scale to that measurement. I got around 47 kg on every spring at 1.800, which is about 103.6 lbs., so i guess this is fine.
#2: yes, i thought about grinding a bit off the shims to fit them properly in the pockets.
I would not have them sink the valves any more. Depending on what rockers you are using there are valve locks that will give you an additional .050 hgt and then you can shim accordingly. Personally I would not worry about it much. Those springs dont have a lot of pressure anyway and .020 or so less hgt wont hurt a thing.
Your method of checking hgt might not be that accurate either. Try the method in my picture below. Cut a piece of coat hanger wire a little long and then grind the end a bit at a time until you can just squeeze it under the retainer. Then measure your wire with the calipers. Make sure it is straight in line with the valve. This method works great on stock heads with small springs where you cannot get a hgt mike in to measure.
Make sure you pull up on the retainer to seat it real good on the keepers. Either that or what I usually do is let it drop down to the valve guide and smack it lightly with a small hammer. You will be amazed at how much hgt you will gain just seating the locks.
I will visit my machine shop with the heads today, just to talk with the machinist about it. When i hold a straight edge to the valve stems, all intake valves are slightly more "down" than the exhaust valves. Maybe just for evening them out and gain the extra space for shimming
i would like to use 0.030 shims too, because i thought the same (0.015 is VERY thin).
Thanks for the idea for checking the installed spring height! I was afraid too that my measuring method isnt that accurate!
I pulled the retainers up to seat the locks, but im gonna try the hammer tapping method too.
so, do you think with these springs it wouldnt be a problem if the installed height would be like for example 1.770 (1.800 - 0.030) since in this example it would be 0.010 smaller than the lunati claimed tolerance of +/- 0.020? I understand that UNDER 1.800 is better than UPPER because of maybe the case of valve floating due to weak seat pressure.
Lot of very useful stuff to learn here, thanks a lot!
Last edited by 71OldscutlassS; April 7th, 2022 at 11:03 PM.
I will visit my machine shop with the heads today, just to talk with the machinist about it. When i hold a straight edge to the valve stems, all intake valves are slightly more "down" than the exhaust valves. Maybe just for evening them out and gain the extra space for shimming
i would like to use 0.030 shims too, because i thought the same (0.015 is VERY thin).
Thanks for the idea for checking the installed spring height! I was afraid too that my measuring method isnt that accurate!
I pulled the retainers up to seat the locks, but im gonna try the hammer tapping method too.
so, do you think with these springs it wouldnt be a problem if the installed height would be like for example 1.770 (1.800 - 0.030) since in this example it would be 0.010 smaller than the lunati claimed tolerance of +/- 0.020? I understand that UNDER 1.800 is better than UPPER because of maybe the case of valve floating due to weak seat pressure.
Lot of very useful stuff to learn here, thanks a lot!
BillK gives some very helpful advice.
#1 You DO need to seat the valve locks to be accurate on spring pressure height. I would tap the valve stem using a piece of brass AND a light hammer. The straight edge and caliphers could cause incorrect measurements.
#2 BillK's idea to measure spring seat height is excellent. Have a set of feeler gages to check the gap if its more than 1.800".
#3 Take one of the valve springs and measure it at 1.770" to see what the pressure is......then you will know.
#4 Don't sink the valves deeper.
BillK gives some very helpful advice.
#1 You DO need to seat the valve locks to be accurate on spring pressure height. I would tap the valve stem using a piece of brass AND a light hammer. The straight edge and caliphers could cause incorrect measurements.
#2 BillK's idea to measure spring seat height is excellent. Have a set of feeler gages to check the gap if its more than 1.800".
#3 Take one of the valve springs and measure it at 1.770" to see what the pressure is......then you will know.
#4 Don't sink the valves deeper.
#1: im definitely gonna try that!
#2: and measure the height again with this method.
#3: i will do that, but i guess, since that i have 103 lbs. Or slightly more pretty on point at 1.800, it will be more like 104-105 or something at about 1.770. Is this ok?
#4: ok, i would love not to have them to sink deeper! But just for my curiousity, is it ok that the valve stems are not perfectly even when checked with a straight edge? I can even see it when i look over the stems with retainers installed that the intake valves are sitting very slightly lower.
Thanks a lot for the help! I really apprechiate it!
Lunati advertised spring rate for the 73126 valve spring is 364 lb/inch. Lunati advertised coil bind for that spring is 1.100". Simple math indicates that with a valve lift of 0.485" you shall have a touch more than 176.5 lb more spring pressure ( .485 X 364) than that when valve is on the seat. If seat pressure is ~ 103 lb, open pressure would be ~ 279.5 lb (103 + 176.5). A valve spring shim of 0.030" thickness shall add ~ 11 lb ( .030 X 364). You should have no issues with a valve seat pressure of up to about 120 or 130 lb and you shall have plenty of clearance from coil bind. That being said, you should verify each valve spring for adequate coil bind clearance; 0.060" is the generally accepted figure.
Now, i had a few hours time to tinker around with my heads.
first, i cleaned the grooves of the valve stems, the retainers and all the valve locks from oil, because i found that it is very difficult/impossible to seat the locks snug in the retainer when theyre have a slightly film of oil on them.
After the cleaning, the retainers seatet perfect on the locks with a slight tap with a small hammer and a hard piece of plastic i found in my garage.
Then, i filed a piece of thick wire like bill adviced, to exact 1.800 due to my digital caliper to see where my measuring is. And voila, ALL valves are over 1.800.
Seems like my measuring with caliper and straight edge in combo with not very well seated retainers/locks was a completely fail .
I measured every valve with my piece of wire and feeler gauges to compensate differences, these are the results:
Lunati advertised spring rate for the 73126 valve spring is 364 lb/inch. Lunati advertised coil bind for that spring is 1.100". Simple math indicates that with a valve lift of 0.485" you shall have a touch more than 176.5 lb more spring pressure ( .485 X 364) than that when valve is on the seat. If seat pressure is ~ 103 lb, open pressure would be ~ 279.5 lb (103 + 176.5). A valve spring shim of 0.030" thickness shall add ~ 11 lb ( .030 X 364). You should have no issues with a valve seat pressure of up to about 120 or 130 lb and you shall have plenty of clearance from coil bind. That being said, you should verify each valve spring for adequate coil bind clearance; 0.060" is the generally accepted figure.
Thanks for the help with the math! Now i understand the thing whith spring rate!
So, for coil bind (1.100"), when i would add a 0.030 shim under my tightest intake valve (#6, 1.804 - 0.030 = 1.774) i would got: 1.774 - 0.485 = 1.289, 1.289-1.100 = 0.189 coil bind clearance.
So, it would be good to go to put 0.030 shims under all my springs?
Last edited by 71OldscutlassS; April 8th, 2022 at 10:15 AM.
Should be fine. Always verify to be absolutely sure! And you probably won't have more than about 300 lb open pressure. Most flat tappet cams should be safe with up to about 350 lbs.
Should be fine. Always verify to be absolutely sure! And you probably won't have more than about 300 lb open pressure. Most flat tappet cams should be safe with up to about 350 lbs.
Ok, i will check that especially for the closer measurings again on the drill press with a scale and with the 0.030 shims.
It just makes me a bit nervous since lunati claims for that +/- 0.020 tolerance and i havent not much self expierience to this topic to say that its no problem to go over these tolerances. I dont want a broken spring or something like that .
Ok, i will check that especially for the closer measurings again on the drill press with a scale and with the 0.030 shims.
It just makes me a bit nervous since lunati claims for that +/- 0.020 tolerance and i havent not much self expierience to this topic to say that its no problem to go over these tolerances. I dont want a broken spring or something like that .
Thank you for your help!
A. +/- .020" is for new springs. Are you using new springs ?
B. If you don't shim the exhaust springs at least .030", you could experience valve float earlier. Re-check the valve pocket heights. They seem to vary almost .030".
C. Check spring pressure at 1.800". Write it down.
D. Check the spring pressure at 1.770" Write down the number.
E. Check spring pressure at 1.285" (1.770 - .485") 1.285" is full valve lift. Write down the number.
A. +/- .020" is for new springs. Are you using new springs ?
B. If you don't shim the exhaust springs at least .030", you could experience valve float earlier. Re-check the valve pocket heights. They seem to vary almost .030".
C. Check spring pressure at 1.800". Write it down.
D. Check the spring pressure at 1.770" Write down the number.
E. Check spring pressure at 1.285" (1.770 - .485") 1.285" is full valve lift. Write down the number.
A: No, my springs are not brand new, i had them installed/driven for about one summer (weekend car)
B: ive never had any kind of valve float with these springs at ~ 5000 rpm, they have been installed with 0.030 shims.
B2: i guess, its not a spring pocket height variance, i guess that maybe the machine shop wasnt that accurate when the new valves (2.000" intake and new exhaust valves) have been fitted in. Thats why i thought about maybe have them fit the intake valves slightly deeper to get a installed height like the exhaust valves.
C,D,E: ill check that again and write all down!
edit: i checked all the springs again and i got:
@ 1.800: 103 - 106 lbs.
@ 1.770: around 120 lbs.
@ 1.285 (full compressed height): 291 - 297 lbs.
(plenty of room for coil bind safety)
Theres is alwas a slight variance between all 16 springs, but i guess thats normal?
Last edited by 71OldscutlassS; April 11th, 2022 at 09:24 AM.
A: No, my springs are not brand new, i had them installed/driven for about one summer (weekend car)
B: ive never had any kind of valve float with these springs at ~ 5000 rpm, they have been installed with 0.030 shims.
B2: i guess, its not a spring pocket height variance, i guess that maybe the machine shop wasnt that accurate when the new valves (2.000" intake and new exhaust valves) have been fitted in. Thats why i thought about maybe have them fit the intake valves slightly deeper to get a installed height like the exhaust valves.
C,D,E: ill check that again and write all down!
edit: i checked all the springs again and i got:
@ 1.800: 103 - 106 lbs.
@ 1.770: around 120 lbs.
@ 1.285 (full compressed height): 291 - 297 lbs.
(plenty of room for coil bind safety)
Theres is alwas a slight variance between all 16 springs, but i guess thats normal?
Good job !!!! Now you have useful numbers to save in your toolbox. Shim the valve spring pockets with .030" shims to get as close to 1.800 as you can. 1.800 to 1.770 (.030") shows a difference of 14 pounds, so, a few thousanth's isn't a big deal.
As a reference,
W-31 valve springs (2.00" intake valves):
84 pounds on the seat, 214 pounds at full lift.
W-30 valve springs (2.072" intake valves):
125 pounds on the seat, 308 pounds at full lift.
Last edited by OLDSter Ralph; April 12th, 2022 at 08:38 AM.
Good job !!!! Now you have useful numbers to save in your toolbox. Shim the valve spring pockets with .030" shims to get as close to 1.800 as you can. 1.800 to 1.770 (.030") shows a difference of 14 pounds, so, a few thousanth's isn't a big deal.
As a reference,
W-31 valve springs (2.00" intake valves):
84 pounds on the seat, 214 pounds at full lift.
W-30 valve springs (2.072" intake valves):
125 pounds on the seat, 308 pounds at full lift.
thanks for the info about the W-31 and W-30 valve springs, good to know!
I would be close to 1.770 when using 0.030 shims only at 3 valves. i could use 0.015 shims on these to get closer to 1.800 maybe if i would smoothen/deburr the lower sharp edges of the damper springs?.
So, 14 pounds isnt a big difference? I really feel a lot less worried if guys with much more expierience than me can confirm that!
Thanks a lot!
Just for my curiousity, would it be possible to lap these valves a bit to gain some "more installed height" on the 3 valves that have the smallest installed height?
thanks for the info about the W-31 and W-30 valve springs, good to know!
I would be close to 1.770 when using 0.030 shims only at 3 valves. i could use 0.015 shims on these to get closer to 1.800 maybe if i would smoothen/deburr the lower sharp edges of the damper springs?.
So, 14 pounds isnt a big difference? I really feel a lot less worried if guys with much more expierience than me can confirm that!
Thanks a lot!
Just for my curiousity, would it be possible to lap these valves a bit to gain some "more installed height" on the 3 valves that have the smallest installed height?
A. Lapping the valves would take a long time to gain .001".
B. Just shim them with .030" shims on the exhaust valves that need it, and put you in the =/- .020" range of 1.800". BillK can chime in on what he thinks.
C. The 1.770" spring pressure compared to 1.800" was to show you that the spring pressure increased 14 pounds compressed an extra .030".
D. Showing you the W-30, W-31 pressures just shows you that your springs would be ok at 1.800" or 1.770" and they are comparable.
BillK, 67OAI tell him what you think.
Last edited by OLDSter Ralph; April 12th, 2022 at 08:48 PM.
Ok, so im going to grind my 0.030 shims to get a slight taper to clear the spring pockets and put them under all my springs and assemble the valves in the next time.
I feel much better now, knowing that it should be good to go! Without any kind of deeper self expierience, it makes me always a little nervous, when i read something like '..its a must to stay in the tolerance of exactly +/- .020'
i pray that all will work good without any issues!
Again, thanks a lot for the very well explaination about the math of valve springs and your expertise!
Today, i was able to put the heads back on. I used fel pros 8171 gaskets (0.045 compressed height?).
i cc'd the head at cyl #1 (with a CD, some grease and oil) and got a result of somewhere of 65 cc head volume. I heard that those heads are listed as 64 cc, but most of them have more like 68 cc. Can it be that my cc number is that low just because of surfacing the heads and maybe because in the larger intake valve? My deck clearance is about .027 to .028. With these specs in Summits compression ratio calculator, i get something like 10:1. I assume that this is fine.
I also just layed the RPM intake manifold, which is coming off the box brand new (no milling etc.) on the motor to check the fitment. These are pictures of all 4 corners at the head/intake meeting surfaces:
For me, this looks like a good fit.
Maybe good enough to use fel pros valley pan gasket. I have SCE gaskets here too and im going to try which fits best.
The Felpro are .042" compressed. Yes, just getting the heads milled can lose that 3cc and get your 65cc number. My #6 head with the larger 2.07" intake valve also CCd at 65. If your motor ran fine before, use the same octane fuel. Did you use the same cam or similar specs? I ran into pinging with similar quench and a 1/2 point less compression but was running the small 204/214 cam. I'm surprised those pistons are that far in the hole, there must have been very little block decking. That intake fits nicely. You may find the much thicker SCE intake gaskets a tight fit. If they don't fit, just use your valley pan.
Today, i was able to put the heads back on. I used fel pros 8171 gaskets (0.045 compressed height?).
i cc'd the head at cyl #1 (with a CD, some grease and oil) and got a result of somewhere of 65 cc head volume. I heard that those heads are listed as 64 cc, but most of them have more like 68 cc. Can it be that my cc number is that low just because of surfacing the heads and maybe because in the larger intake valve? My deck clearance is about .027 to .028. With these specs in Summits compression ratio calculator, i get something like 10:1. I assume that this is fine.
Did you include head gasket thickness in compression ratio calculations ?
The Felpro are .042" compressed. Yes, just getting the heads milled can lose that 3cc and get your 65cc number. My #6 head with the larger 2.07" intake valve also CCd at 65. If your motor ran fine before, use the same octane fuel. Did you use the same cam or similar specs? I ran into pinging with similar quench and a 1/2 point less compression but was running the small 204/214 cam. I'm surprised those pistons are that far in the hole, there must have been very little block decking. That intake fits nicely. You may find the much thicker SCE intake gaskets a tight fit. If they don't fit, just use your valley pan.
i had the block and the head surfaces just "surfaced" to get straight and nice sealing surfaces. My machinist said that they almost took nothing off the heads because they have been very straight.
I guess i'll have to live with this compression ratio of about 10:1. I will try if it'll work without pinging or something with our european 95 octan, if not, we have 98 or even 102 octan here.
now, im getting closer to determine my pushrod lenght. This is the first time im doing this and unfortunately i have no test valve springs.
The rods which have been installed when i purchased the engine are measured from tip to tip a bit longer than 8.400, so i guess their scripted lenght is 8.400 (because of the radius of the ball tips).
I have my old lunati lifters here and im going to use these in the new build too, so i decided to stack one of them with washers till the plunger is touching the snap ring, like if the lifter has oil pressure to make some kind of solid test lifter:
Then, i tested #1 intake valve with a 8.400 pushrod. painted the valve stem tip with a marker, set poly lock to zero lash and turned the engine 3 times over, this was the result:
For me, this looks like those pushrods are too long. Maybe in the further engine theyre have been right, but i guess, since i had heads and deck surfaced theyre too long now.
Then, just for trying, i adjusted my trick-flow lenght checker a bit shorter and got this pattern (the lenght checker is strong enough to handle my valve springs):
i think this looks much better. I measured the lenght checker the same way as i got 8.400 on the old pushrods and got something like 8.260.
What worries me a bit is, that if i would like to go more shorter than that, my comp roller tip rockers would be close to interfering/grinding with the bottom of the rocker studs (ARP 7/16 to 3/8-24).
i apologie that my lenght measurements are a bit guess work, but this is the first time im doing this and i always have to calculate from metric to inches when i measure something and sometimes this is a bit confusing when growing up and working the whole life with the metric system .
thanks for any thoughts about this topic!
Edit:
My rocker pads arent milled and im using comp 4842 guide plates and the "tulip shaped" ARP 5/16 to 3/8-24 rocker studs. Depending from what i tried, i would need pushrods from around 8.250 to 8.300 for a good pattern, but its true, its not possible to go shorter than 8.350 without bottoming out the comp roller tip rocker arm on the tulip shape of the rocker stud due to its large body.
Are, for example harland sharp 5016 or equivalent rocker arms giving more room to the rocker arm stud? I wouldnt feel very comfortable to grind on the rocker arms for some clearance.
If its possible, i would like to avoid pulling the heads again to mill the rocke pads down.
Thanks for any advice!
Last edited by 71OldscutlassS; April 20th, 2022 at 10:36 AM.
Here is the Harland Sharp and others true roller rocker base.
Thanks for the picture, its just difficult to see from a picture if their body goes less far down than on the comp rockers. Maybe someone has both for comparison.
Top two use a 3/8" stud and the bottom is 7/16". The true roller rocker body is wider at the stud.
Thanks for the pictures! Have you had the same problem like me with the blue rockers? (grinded some material off?) But, if the body is wider at the stud, it could work for me.
My plan was to keep the comp guide plates and the arp 5/16 to 3/8 studs for maybe using with true roller rockers. I already have the short poly locks. Im not sure what to do now. If i would know that its no problem, i think i would just grind/file away the interfering edge on my comp rockers. Definitely the cheapest solution.
The Scorpion are a quality US made rocker arm. No, it was the rocker arms bottoming out on the stud nut. You could try slightly clearancing your roller tip rocker arms.
March 29th, 2022, 12:35 PM
.030 or nothing.
.
