[Antiwork]

Ok, a couple of questions on the valve train for my project. Here’s what I’m working on: I have a 71 400 short block with the silvolite cast pistons (both sets of valve reliefs). I’m using a set of 64 #716 heads so I can use an early style intake. This combination is going into a 31 Ford coupe, hence the somewhat unconventional setup.

I’ve been told that I need to convert to screw in studs. Are these absolutely necessary with something like the 068 flat tappet or a mild Lunati hydraulic roller? A local shop quoted upwards of $500 to convert the heads (minus parts) does that seem like it’s in the ballpark? It’s a good but more than I was anticipating. That was to mill the stud seats 3/8” and tap for the ARP studs, by the way…

Aside from the stud question, assuming I went with either the 068 flat tappet or one of the milder Lunati hydraulic rollers, like this one https://www.lunatipower.com/voodoo-r...8-270-278.html what springs would I need? The Lunati site isn’t much help there. Is there likely to be machine work needed to the heads to install the proper springs?

[Jay S]

Do not use a hydraulic roller with pressed in studs. If the pressed in stud comes out the lifter will come out, mis-align and destroy the cam and lifter. Flat tappet will just throw the lifter into the valley, you can put it back in, take care of the stud issue and run it again.

The 068 flat tappet should work fine though. We usually hold the valve lift to .45” or below on pressed on stud engines, and limit spring rate to stock type rates.

[Antiwork]

Originally Posted by Jay S

Do not use a hydraulic roller with pressed in studs. If the pressed in stud comes out the lifter will come out, mis-align and destroy the cam and lifter. Flat tappet will just throw the lifter into the valley, you can put it back in, take care of the stud issue and run it again.

The 068 flat tappet should work fine though. We usually hold the valve lift to .45” or below on pressed on stud engines, and limit spring rate to stock type rates.

Thanks for the info. Any feeling on the cost of having them installed?

[b-man]

Your machine shop is way way overpriced. I had my 9770716 heads converted to screw-in studs about 6 years ago and the cost including parts was less than $250, right now it shouldn’t cost much more if not the same.

I agree you’re probably fine running the 068 with the stock press-in studs, forget about any roller or other more aggressive cam if you don’t want the studs either pulling out or breaking.

I converted my heads to screw in studs and Crower stainless rockers even though I’m only running the 068 cam. Sometimes the press-in studs can back out even in stock applications, hence why the factory offered an oversized press-in stud as a service replacement part.

From what I’ve read once the heads have been cleaned using the now most common ‘shake and bake’ process the press-in studs lose some of the their press tightness and are a little more likely to back out. Good old fashioned hot tank cleaning didn’t have this effect so something to consider.

Converting to press in studs is worth the added cost in my opinion, adding reliability with both better rocker stud retention and stronger studs is never a bad idea. The factory finally put screw-in studs in all their V8 heads, both in performance applications and grocery getters beginning in 1974.

Machine For Screw-In Studs, Helicoil For 7/16, Cut Bosses .250" - $179.00

16 ea. 101 - 7101 ARP Rocker Arm Stud Kit - $48.00

16 ea. Helicoil Insert 7/16-14 - $16.00

On the subject of valve springs you can use pretty much any spring that works for the common standard 1.58” height with pressures in the 250 to 275 pound range for the flat tappet 068. The HO-Racing springs I used were bought probably 25 years ago but again anything available from a quality supplier will work. Keep in mind the ‘64 heads used a shorter 1.53” installed height, the springs I used were made to be used for both 1.53” and 1.58” installed height.

For the hydraulic roller use whatever the cam manufacturer recommends.

16 ea. H-O Racing VS-11 Valve Springs

16 ea. 607-STA Isky Valve Spring Retainers - $92.00

[steve25]

The 068 cam was the Tripower cam used in the 421 motors with those same 716 heads in basic terms.
500 bucks seems like a crazy price to install screw in studs.

I would just get them drilled and pin’ed after looking the heads over for ware in the cast guide holes and for notches in the studs themselves which is due to worn guide holes that causes the rocker to rub on the studs.

If the guide hole show ware then your stuck with two choices, replace the head, or change over to screw in studs.

Check all of your rocker balls on the flat side for signs of cracking due to excessive torque adjustment.

You should run Crower 68407 springs, especially if a valve job has been done.

[Antiwork]

I think I’ll try to find another local machine shop and get another quote on the screw in studs.

Any thoughts on valve springs for either of the cams I listed?

[steve25]

As I posted the Crower 68407 will be good for the 068 cam, however that hydro roller will need Crowers 68405 springs, but with modifications.

You will either have to cut the spring seats deeper and use different retainers, or run new longer valves.

With the hydro roller you will need different length push rods and for sure screw in studs.

The tops of the valve guides will have to be cut for positive valve seals also since the aftermarket retainers needed will not hold the stock valve seal O-ring.

[Steve C.]

From the Lunati catalog, valve spring stated for the 20510711 Voodoo hydraulic roller cam:

73195 spring / dual
Rated 115 lbs at 1.700"
1.050 coil bind

Obvious the pressure will depend on the actual verified installed height.
But even installed at 1.700" I don't think I would want to run a Voodoo hyd roller lobe with 115 lbs spring pressure.


.

[Antiwork]

Originally Posted by steve25

As I posted the Crower 68407 will be good for the 068 cam, however that hydro roller will need Crowers 68405 springs, but with modifications.

You will either have to cut the spring seats deeper and use different retainers, or run new longer valves.

With the hydro roller you will need different length push rods and for sure screw in studs.

The tops of the valve guides will have to be cut for positive valve seals also since the aftermarket retainers needed will not hold the stock valve seal O-ring.

I missed your recommendation the first time around, sorry about that.

Just want to make sure I’m understanding you correctly: are the mods you listed: spring seats cut, valve guides cut for positive seals, etc. needed with either spring you recommended, or only the ones for the roller cam?

[steve25]

Only for the roller.
The stock valvetrain install height that works fine for the 068 cam with the 68407 springs will not work with the over .500” lift of that roller.
That combo needs more installed height by means of longer valves and or cutting the spring seats about .060”

[tom s]

Don’t pin the studs.If you want to chance pressed in studs,drill and tap for a small set screw so when you break one you will be able to get it out.JMO,Tom

[b-man]

Originally Posted by tom s

Don’t pin the studs.If you want to chance pressed in studs,drill and tap for a small set screw so when you break one you will be able to get it out.JMO,Tom

Agree 100%.

However I wouldn’t bother since they’re a weak bottleneck design. Do it right and convert to screw-in straight 7/16” studs.

At least the early Super Duty heads had the much stronger straight 7/16 press-in studs, retained by a set screw.

I saw a set of 980 ‘63 421 heads sitting on a workbench at Tom’s home some years back and was pleasantly surprised to see the rocker studs weren’t pinned as I had always assumed but retained using what looked like either 10-32 or 8-32 set screws.

[steve25]

When I saw a set of 980 castings years ago it looked like 8-3/2” to me also.

These days with the electric welding rods we have available a quick tack weld 180 degrees apart works also and can be easily ground out for screw in studs with a cut off disc.

Also if your going with the HR for more power due to it greater lift and faster rates I would not run stock 50 plus year old valves in the heads!

[Antiwork]

Dragging this back up as I’ve made some slow progress, leading to more questions.

As a reminder, I’m running a 1971 400 block and 1964 716 heads (to mate up with an early style intake).

I finally found a decent local shop that wasn’t insane on pricing to do the head work I needed done. I had a set of screw in studs installed (7/16), new valve springs installed and the heads generally gone over to make sure everything was in good shape (skimmed the deck surfaces, touched up the valve seats, new seals, etc.

Anyway, The short block is assembled and I’m getting closer to being able to install the heads and finish off assembly. I’m a little stuck on what I should do for rocker arms. I’ll be running a small roller cam (Lunati 711). My heads do not have guide plates. Putting aside the fact that getting any parts right now seems difficult, what should I run here: standard roller rockers, self aligning roller rockers, just a basic stamped rocker?

[25stevem]

Did the shop tell you how much valve lift you can safely run with the springs they installed, and how much lift will this Hydro roller Cam you will run have?

[Jay S]

Probably the easiest options is either a 7/16 rocker ball on the stock rockers, or better would be a self aligning full roller Ford Windsor rocker arms with 7/16” studs. Not sure who all makes self aligning, PRW makes some. More than likely the lowest ratio available would be 1.6 though. Not sure 1.5s roller rockers are available from any source in self aligning style.

https://www.summitracing.com/parts/p...0206/make/ford

We have done 1.8 PRW stainless Ford Windsor rockers on a Pontiac, shown in the photo on stock length valves. Most of the Ford Windsor rockers have good geometry as long as the time is taken to get the pushrod length correct.

[Antiwork]

Originally Posted by 25stevem

Did the shop tell you how much valve lift you can safely run with the springs they installed, and how much lift will this Hydro roller Cam you will run have?

The shop said anything under .600 should be ok.

According to Lunati, lift should be .515/.530:
https://www.lunatipower.com/voodoo-r...8-270-278.html

[25stevem]

Ok, because anything over .550” lift with out guide plates will be a mess with those heads after a few thousand miles.

[Antiwork]

Originally Posted by 25stevem

Ok, because anything over .550” lift with out guide plates will be a mess with those heads after a few thousand miles.

Could you elaborate on what you mean by “a mess”?

[AG]

Can't guide plates be used since he has screw-in studs?