Cutting spring seats on 440-1 heads?

Considering a cam change to more lift, that will warrant a spring height change, that will warrant a +050 lock, that will put the retainer pretty close to the T&D rocker setup I am running. Been there done that and don't like it. Usually aluminum in the oil filter from the retainers clearancing themselves is the result.

Anyways, my heads are set up with .060 PAC spring locators right now to get me to 1.950.

Naturally, PAC doesn't offer anything thinner, so I am machining something off at the seat to get there I am afraid.

What I am considering is taking some off the spring locators and some off the seats. Maybe .020 off the locators that should require .030 off the seats.

Anyone done something like that? Safe?

I've taken some off the seat of both the SR and -1 heads maybe .010-.015" ...I'm not sure what the max # Indy recommends but it isn't much. It'll be real difficult to cut a spring locater because they are hard. What I found is the inner radius of the locater can interfere with the guide boss, which can free up some unexpected installed height. Motorsports Unlimited says he has a .040 locater that works but I haven't used them. You might consider using a 1.50" OD spring which might put the retainer about 1.40" PSI426DR works pretty good. This is one advantage of using the paired rocker system, it opens higher lift possibilities. The SR used a TD single-shaft and I was able to NET about .740" with the 1225PAC 1.52"? OD

Thanks Hardcore. I run the PSI424R spring on it with the PAC 104 locators and R405 retainers. The cam is puny lift wise. I only have .714 at the valve....

So setting them up at 1.950 got me to .086 CB with the 424R spring and the set I just took off had, lets just say a lot of passes lol.

Switching everything around will get expensive, and the 424R spring has been great for me.

The problem spot to me looks like it is on the intakes right at the top of the spring seat. Looks pretty thin there, and why I think I need to proceed with caution.

Probably call Indy tomorrow.

Were the seats cut for the locators? If so then you might be at the limit. If not then you can probably safely remove .060.

I think machining the locators would be risky and they'd have a tendancy to crack and chip.

Can't you find a stiffer spring with the same installed height that will handle that new lift? A triple spring maybe?

My -1's run Pac 1224 (1.625 dia.) springs at 1.950" with Pac locators that are .060 thick? I did skim cut some of the pockets to gain clearance. It has paired T&D 1.7 rockers. No clearance issues to the retainers. The heads were used when I bought them 13 years ago. Made over 1000 passes since.
Doug

I have .030 spring cups for my PAC triples. So somebody out there may have them in your size? I also used +.100 retainers and +.050 locks to end up at 2.070 on the intakes, heads uncut.

It took some time trying different parts but I was able to get right at 2.100 installed height on my Indy EZ heads. I had to mix and match retainers and locks. I discovered that different brands measured things differently and that you couldn't trust the mfg specs.

It's not the spring pressure the 424 R should be plenty enough. Its 656lbs/in. It's the installed height to get my coil bind where I need it if I go in the upper .700s lift. I did some checking here tonight and a few of them are actually closer to 1.940, which puts me at .086 from coil bind. These springs have 1.14 coil bind. I would like lift somewhere in the upper .700s if I can get it. Talked to Tim at Bullet the other day and he said .768 (honestly I would like a little more) which would put me at .032 CB so I have to find some spring height somewhere unless I change everything.



DW have you ever measured how close the retainers are to the rockers? I run bushed T&D, maybe different? With my R405 retainers and +050 locks I can get 2 pieces of thick paper between them that measure .020 total. Feels like it might be .025 or so? I don't think I could fit a 1.625 spring on it. The DR425R is 1.525 and the R405 retainer is 1.450. Its a nice setup if I can get some more installed height.



I have cups. And naturally they are .060 lol.

I run a dual spring and I always like the ID locators that fit the inner to keep everything centered. If I ran cups on these springs the inner would be centered only by the spring itself. Don't like that.

I need to call PSI tomorrow and see what locators they know of that will work with these springs. All I seem to see are the PAC S104. Its 1.55 .770 .635.



Oh great! So I might order something expecting it to work and it won't.

On a side note, why is everything with locks and retainers in increments of .050? Seems to me .025 would be better so guys like me don't end up in installed height lala land.

I'd say .030" retainer to rocker. Been awhile since the measurement was made. been this way for 12 years.
Doug

For gains in camshaft, you may need to upgrade the spring even at the same RPM. But, it's likely some gains will come with RPM/cam IMO. I was looking at some of the PAC 133x series which is an even shorter installed height but allow for .750-.800 NET They are pretty small O.D. and light so they'd be easy on the rockers and lifters too. What is the 'intensity' of the cam you have? Depending on what you're looking for, I may still have a 4/7 swap or 4/7 3/2 cam around. Or even a rocker system...

When I was sorting this stuff out I ordered a bunch of single retainers rather than full sets. I built a spreadsheet that kept track of all of the information. I'll attach a copy.

Andy, what is the last column(tool) referencing?

I have a 10 degree taper tool that I use to measure the installed height for different retainers. I think that column was with the measuring tool, but I'm not 100% sure anymore. I used to measure the retainers with a taper tool since different retainers had different installed heights even with the same locks.

Thanks. That's actually a good idea in the long run to avoid having several sets laying around you will never use. I have springs locks and retainers cups and all sorts of stuff I bought and never used that I need to put on the marketplace, from this deal over the years.





Dwayne, I can't remember, it's been quite a few years, but do you happen to remember me talking to you about this setup several years back? I think I did? Was breaking stuff and you pointed me in the direction of Motorsports Unlimited I think? To a guy that got me set up with the valve springs and parts? God I been so many directions over the years with this I lost track, but I thought you told me what I needed and where to get it. And it worked. Apologies if I am mistaken.

I don’t think it was me.

Here is a picture of the retainer measuring tool that I made. I found that retainers from different mfgs had different installed heights. There isn't a spec for retainers so I made a tool with a 10 degree taper that allows me to measure the different retainers.

And I see it with this setup I am fooling with right now Andy. So I set one up at 1.950. Switch to a +.050 lock....614 Comps.

Around 2.00 Right? Noooope. Now we are +.070 setting at 2.020...I can see + or - .005 or so but .020?

Since these are PAC retainers maybe I should try locks from PAC?

Maybe I get a true .050 and gain some rocker clearance I was worried about originally. When I checked it the other night I didn't realize I was getting .070.

you might talk to Mike at B3racing, the geometry correction he uses moves the rocker away from the retainer

Yeah that was the problem I was having. I had no way of knowing what the installed height would be without actually ordering the parts and measuring the result. The +050 and -050 numbers are in comparison to other parts that the same mfg makes, not to an industry standard. There is no industry standard for how retainers are made so the taper can be at a different height on a different part number. Bottom line is that you have to order some parts that will fit and measure them.

OK so I dug out some old comp tool steel retainers I had on it before and tested them with the locks. 1.955 and with the +.050 2.05....

So the PAC retainers and Comp locks dont like each other, just like you said.

In PAC's catalog it says this about the locks...



That sounds like some Chinese garbled english saying we took 10 degree locks and retainers and made them not quite 10 degree.....

And then I noticed on Summit, the PAC R405 retainer is listed as a +.050? Really?

Its not listed as a +.050 in PAC's catalog......So which is it?

.050 +.050 still doesn't add up to .070

Put a little bigger cam in it I thought......Just change the installed height I thought......Silly me thinking this might be easy.

When I’ve used PAC stuff together it’s been spot on.
Doug

I won't cut the spring seats on heads now after going through into the water jackets on a different brand and set of 440 heads

Thing is, these locks should be PAC too. Only thing I can figure is maybe the locks got switched out at the machine shop somewhere along the line when I had the heads freshened.

I need to order PAC locks and see where they measure up compared to what I have.

Come to think of it...on the single shaft SR set-up I put the installed height on the 1225's with a 405 retainer closer to 1.97 with a .06 locater. Mapping out the sweep for .740net, it helped moving the shafts up. I had new sleeves (which adapted the shafts from the .750 fulcrum to the standard Mopar pedestal) made that used an offset hole. This raised the shaft some which also increased rocker clearance. The TD rockers I had had an undercut for spring clearance which compromises the service life of the rocker. That's one reason I erred on the light side for open pressure.

& that is what the B3 spacers do also correcting the geometry

Your car is fast and consistent. I’d leave it alone. Lol

The sweep on my heads the way they are set up has always been perfect. Thank god I never had to go through all that. After what simple cam and spring height change has turned into I don't want any part of that.

I might race Mopars, but I have always said I would be way ahead of the game and closer to retirement if I stayed with a BBC all these years. I originally was a GM guy.

Walmart probably has all the parts in stock today to get my spring height corrected. :laugh2



Thanks 71. As is your car too!

I have always wanted to swap the cam out as this old cam is from way back in the day when I was footbraking running gas. It works, but you know how it is when you are running something that you are pretty sure is holding you back.

If I cant come up with a plan this week it will get cleaned up and put back in.

Respectfully, I was careful not to say what I did optimized the geometry but, it was an improvement. B3 is a sharp guy his kit articulates the fulcrum differently. Also, I looked at some old pics and see I used the r505 retainer...not the 405.

That's good to learn. It seemed on mine they looked good until about .700 net then started sweeping inward past the point of origin IIRC. As much as I contradict the action, I agree and probably wouldn't recommend messing with what's working so well.

Trust me I get it. If we as racers aren’t trying to continue to make things better, we get bored. Especially in the off season. I’ll be looking forward to see your outcome.

Well I figured out how DVW can run a 1.6250 and I can't awhile ago.

My old T&D rocker on bottom and the newer bushed set I run now on top.

Deeper clearance cut.

I did break one of the old intakes. That deeper cut is definately weaker.

These are way old. Used when I bought them in 2012.
Doug

OK nevermind....I see now. You have the paired rocker shaft setup....Different deal altogether.

I still run the peasant full shaft T&D setup.