[chiphead]

That pretty much describes the 69 wz code 62 headed 400 I've got. I would expect it to pull 5300 RPM. This build s starting to show its age so I don't think I'd wing it up there that often.

[chiphead]

So I got the #1 valvesprings off. The guides are machined for .500 positive seals. The retainers and locks look aftermarket and there was no O-ring present. The IH miked at 1.625 on the intake and 1.635 on the exhaust. I'll reuse the retainers and locks with the new setup.

I'm going back with Summit 2802 and Crower 68404 springs. I scored those HLJs lifters from ebay. Going to call butler and see if there is a set of rocker studs and balls that will let me re-use the stock rockers and stock length pushrods.

Should I install the cam per the cam card, or advance it 4*?

[Jay S]

I would install it at 109, which should be what it is already set for dot to dot.

[chiphead]

A few more questions.
What dizzy gear should I run with the summit 2802? I've got std, bronze and bop polymer.

Do I need to disassemble the new lifters to clean them?

Do I need to remove inner springs for break in? Can I leave the inners out for the easy shakedown street runs?

[Dragncar]

Iron gear with .030 hole in the plug in front of it.

[Jay S]

With the 2802, 1.5 rockers and HLJ lifters you can break it in without pulling the inner springs. If you want to be extra careful, or if it had 1.65s, I would pull the inners and stay below 4000 rpm.

Definitely run the stock cam gear.

[chiphead]

OK got an issue. With the .488 lift of the 2802 and the retainer/guide/viton seal stackup, I need an additional .100" of retainer-to-seal travel to achieve .050" of retainer to seal clearance at max lift. I'm at 1.6 IH. This is a low buck motor, so I don't want to remove the heads for any machine work.

This is a pic of the retainer I've got. It measures .340" from the inner spring perch to the end of the retainer. Seems like there should be retainer options that'll give me more clearance.
Is there a shorter retainer I can use?

[chiphead]

Did some more digging.

Crower catalog recommends the 87048-16, 7 degree retainer with the 68404 spring. It says it adds about .087 to the IH, There is also the 87048D-16 retainer that gives .150 IH.

Can I use any 7 degree, 11/32 valvestem lock with these? Summit has locks in stock but are listed as SBC.

The other option is the Comp 740-16 retainer and matching 10 degree locks.

There are also +.050" lock options.

Any guidance on how to make this work?

[Holeshot71]

Those stock retainers can be cut back .100 or so on a lathe. If you don’t have a lathe you can take a caliper and scribe a line around the retainer then cut them back on a bench grinder to the line. Doesn’t hurt to remove any sharp edges after cutting. It takes some time but works great. This only works using positive type seals. HTH

[Jay S]

Could you post a picture of the top side of the retainers you have? … to help identify what you have right now

Sounds like you need different retainers. I think Crower lists the IH from stock height.

[chiphead]

Here's the current view from the top and the side, with checking springs installed. I've got .435" lift before the retainer hits the seal. With .488 cam lift, I need .538" for .050" running clearance.

The stock rocker is shown mocked up with a straight 7/16" stud and polylock. No pushrod installed, so the rocker is just sitting there.

[25stevem]

Here’s some of HO racings recommendations for cams to be used with high comp heads.

Note in particular what they call out for the minimum gearing in comparison to the cam duration.

[chiphead]

I agree with that chart. The car has a stall converter and 3.55s. It ran pretty well with the Crane 284, so the 2802 should do fine. Both are in the ballpark of the 744 so the chart holds.
This assumes I can get the retainers to clear. I found both sets of Crower retainers on Ebay, so I'm going to mock it up and report back.

[chiphead]

So the 87048D-16 retainers gave me a IH of 1.685" and about .525" of valve travel before the retainer hits the seal. So shim it up and that's all good.

Next issue is that the stock rocker arm hits the retainers. OK, NBD I've got a set of Crower stainless rockers. But even those are too close to the deep-dish retainer. With valve closed, the arm body is about .026" from hitting the retainer.

What is minimum acceptable clearance between rocker body and retainer? I could get it to clear with at least .050" if I went to 9.2" pushrods.

[chiphead]

Finally got this back together. With 9.250 pushrods, the tightest retainer to rocker arm clearance is .038" with valve closed and .050" preload.

Is that too tight or run it?

[Jay S]

I’d run it. How much preload does it take to make it hit?

[blueghoast]

You could also put the factory sheilds back on top of the springs.
It'll give you a littl more clearanc too.

GT

[chiphead]

It would likely take another .030 of preload to make it hit. To be clear it's the underside of the rocker arm and the top side of the retainer. The OD of retainer to fulcrum clearance is fine. The retainer is deep dish so there's not much valve tip sticking out the top. As a result retainer is very close to the rocker arm

The only other thing I could do is remove the vitons and run the spring shields with the standard dish crower retainer. That would give me enough running clearance for max lift. But I'm afraid oil control would go to chit because I be depending on the spring shields alone. There's not enough clearance for the standard crower retainers and vitons

[Baron Von Zeppelin]

Did you decide to run this and then check for witness marks ?
Or have you done something else different since last post ?

You could do some light controlled clearancing on the rocker arms
- although you probably don't like thinking about modding expensive rocker arms.

You could switch to solid lifters and cam to take out the preloaded slack and get that back to being usable clearance
- but then you have that expense and the labor.
Save the hydraulic cam & lifters for the future rebuild.

The lesser evil is probably clearancing the rocker arms.
A lot of guys in the race section have done that to high quality rocker arms.

[chiphead]

Nope I'm gonna run it unless somebody says it's a no-go.. It's a short term engine and I don't want to grind on good parts or spend $$$ to have the heads done right. I've got a 434 ready to go and I just need this 400 to last long enough to sort the car out.