[fastekibeast]

Hi all!
I'm sorry for my english, I know its not perfect but hopefully you understand what I mean?!
I've a SD performance 260cfm CNC ported #62 heads.
I ordered from Bullet solid roller cam 292/292-06R to my - 69 GTO
Kirk M from the Bullet Racing Cams suggested that I should use PAC-1222X valve springs with suitable retainers, so I bought them.

I did measure the PAC valve springs and I got @ 1.800" 166lbs to 172lbs so there is some minor
deviation in these springs so I need to shim a little bit also.
Valve springs have installed height 180@ 1.800" open 480@1.100, coil bind 1.055", installed height 1.810-1.815" intake 1.815-1.825" exhaust.
I measured the heads I got now intake 1.684-1.697" . exhaust 1.699-1.713".

Valves are Ferrea 6175/6178.

Now, I need to know how much I can in safety measures grind off from valve spring pocket??
It looks like a somebody have been earlyer machined those pockets? Do I need to buy a different kind of valve locks, new springs or something else?
Thanks,
Janne

[Jay S]

If the installed height is around 1.7” with those longer 5.2”+ length valves there has not been much metal removed from the prior grinding on the valve spring pocket. Can easily cut them down .1” if you need to, or get a +.050 keeper and do a shallower cut on the spring seat.

[steve25]

It’s not a problem with stock heads to even cut the spring pocket way more then .100”, but since they are ported and just to be on the very safe side of things I would consult with SD performance .
A ease part way fix is to just use .050” off set keepers/ locks.

[fastekibeast]

I found out my no ported #62 heads which I've been hacked.
There is some meat between the cooling channel and valve spring pockets, I measured the clearance something like 19/64" about 7,5mm in intake and +5/16" 7,8mm in exhaust side.
There where some corrosion in the cooling channel, but like I said non ported heads.
I tried to contact the SD performance about the heads to get some information.
Janne

[steve25]

Here’s a picture of the cut away of a intake port so you can see how much meat is there in the spring pocket.

[Cliff R]

1.700" installed height is stock for Small Block Chevy. There should be a good selection of springs and something that will work for what you are doing without having to move up to 1.800".

What are the cam specs?

Is this a full race application? 180lbs on the seat and up near 500lbs over the nose is a LOT of pressure for a street engine and you are posting in the street section.......

[67Fbird]

wrong springs. You must have stock length valve is those heads for an install of 1.7. I went thru this many years ago with my #62 heads and figuring springs so ordered +.100 length valves when I did my heads. As mentioned there are MANY springs to work with your 1.700 install and lift requirements. I would call Kirk back and explain the situation surely he will have something . Also would assume your heads have had the valve guides machined down as IIRC they only allow for ...525 lift before your keeper bottoms on top of the guide??

[fastekibeast]

Steve25: Thank you for the picture, looks like your head is not as much corroded as mine.

Cliff R: Yes, this will be in street, no racing
Cam specs: adv. 292* /292*, 050" lift 259*, lobe lift
. 3730", LSA 106*, Overlap 80*, valve lash. 024"

67Fbird: those Ferrea valves #6175 5.213" overall lenght, #6178 5.23 overall lenght.
Kirk recommened these PAC-1222X valve springs with earlyer mentioned cam specs I think he should know??

[Jay S]

IMO, spring recommended was fine, run it with +.050 keeper or similar pocket cut with a 1.75 to 1.78” install height. That will put the spring seat pressure about 180-190 lbs assuming your tester is accurate. SR cam your better off being a little high than a little low, it will loose some more pressure with some street driving. If your tester is accurate 1.8” will put the pressures on the low side, 170 is as low as I would ever want to run with that cam, and that would be with a 45* valve. A factory 30* would need more to keep it seated. All the Roller cam Pontiacs I have are 1.8-1.9” height, ussually get there with the longer valves and a small pocket cut. FWIW

[fastekibeast]

Jay S: Thank you for your opinion. I appreciate it.
You said, better little bit far side, how much do you think is little bit? 6-10lbs? I have heard rumors that when you are measuring your valve springs, they should be warmed up in an oven about 180* celsius, 356*F to mimic how they are working in the car. Can you confirm or deny it?

I also was in contact with Dave in SD Performance
He told, he would take safeIy another . 050" in the valve spring pockets, he had earlyer cut down .100". So the +keepers would be much more easy way out.
Janne

[Cliff R]

It is ALWAYS risky cutting spring pockets deeper. If you have invested a lot of fund into those heads I'd pick up the needed room on the other side instead. Or get different springs.

Certainly someone makes a spring that will work with that cam with a 1.700" installed height so you can just stuff them in there and move on.

I didn't see the rest of the engine specs anyplace.

What CID is the engine and what is the static compression ratio?

[fastekibeast]

Cliff : 400 +. 030 over, static 10.2:1.

[Jay S]

No one I can think of tests springs at higher temps, at least not unless they are in a lab, but I obviously don’t know everyone.

If SDP already cut .1” into the spring valve pocket you have something wrong in the part that were initially listed. Stock install height after a valve job with a typical retainer set up is around 1.58”, then your adding .1” to that with a pocket cut, you should nearly be to 1.7” with just a stock length valve. Someone either gave you the wrong valve and they are just standard 5.095” length instead of the longer longer valves, or the retainers and keepers your running are designed for a negative install height (unusual). Suggest you measure your valve lengths and double check what you have before you go cutting a deeper valve pocket. Easiest just to get the .050” keeper and run what you have.

Maybe I assumed wrong, but if Bullet suggested those springs your planning on using 1.65 rockers? IMO Nothing wrong with being 10 to 20 high on seat pressure initially on a SR cam. SR will have more trouble running to low than high. Axles and bearings do not like valve bounce or float.

[67Fbird]

just found it odd that with the +100 valves you STILL have an install height of 1.700 as mine were/are 1.700 with oem valves and keepers.

[fastekibeast]

JayS: I measure all the valves again, all the exhaust valves where 5.230" and intake 5.213".
Yes, I'm going to use 1.65 rockers but now it looks like I can't find anywhere 11/32" +050 valve locks. Out of stock everywhere, not in Finland, E-buy, Summit so if you have #99095-1 Crane I would be very interested.

I'm not sure can you see the picture I included, but if you can see it, imu means intake, pako means those imu+ pako+ is the distance to achieve IH 1.800"

[Jay S]

Sometimes the 7 degree retainers decrease the install height. Most roller cams springs retainers are 10*. I bet that PAC spring kit uses retainers for a LS engine and has a negative height compared to most spring packages. Valve groove was probably different than a Pontiac.

Here are some 7* +.050.

https://www.summitracing.com/parts/man-13084-16


https://www.summitracing.com/parts/sum-174003-4

[fastekibeast]

I have now PAC - R355-16 retainers they did come with my 1222x valve springs.
If I buy the Manley Super 7 locks, then I have to find a Super 7 retainers to fit my valve springs.
I don't want that. I suspect, somebody in this very PY forum have those straight fit Crane #99095-1 locks in the shelf?!
I just have to find him, if I don't find them anywhere else.

[Jay S]

These should work

https://www.summitracing.com/parts/sum-174003-4

[steve25]

Something is not making any sense here!

In your first post you state that you have Ferrea valves 6175 and 6178.
If this is correct then these are 5.213” and 5.230” long.

This means that to use the valve springs you state you have you need to ADD shims, NOT cut the spring seats you get your needed 1.800” or so of installed height and like 190 to 220 psi of seat pressure.

What am I missing here?

Also be sure to check your spring pressure with the retainer since it will compress the inner spring more then the outer one!

[fastekibeast]

Steve: Yes you are right, at first I thought I need to cut those valve spring pockets or buy different kind of locks and shim the springs to fit IH. 1.800. but now, I 've learned that I don't need to be exactly in that height. It isn' t written in Stones, there is s little bit wiggling.
Like JayS said:springs are fine, run it with +.050 keeper or similar pocket cut with a 1.75 to 1.78" IH.
Spring pressure about 180-190lbs.
I included a photo my springs in 1.800" IH.
as you can see, I'm a little bit shy side now, but if I put the together now I 'm pretty close 180lbs with the +. 050 keeper.