69 460 valve train upgrade?

[topgun]

Hi to all. I just got here and even though I am sure this has already been covered before, I have a question about a 460 that Iam building for my car. So here goes. !968 Lincoln Continental,original 460 motor with rail type rockers. Now, I have installed a fresh 460 of the same year and I would like to do away with the rail type rockers. I had my head redone wityh larger cobrajet valves and would like to know if I can just bolt on a set of roller rockers by just replacing the studs and installing guide plates and hardened pushrods without further modifying the heads.If so what length push rods and can I really use B>B> chevy rockers. Any help will be appreciated

[Itoldyouso]

Maybe Paul Kane our resident 460 guy will see and post, but in the meantime, I have a 460 that I used Harlan Sharp roller rockers on. Has screw in studs and guide plates. Been a while since I did it so not sure about pushrod length, but mine has a roller cam anyway so it wouldn't probably be the same. You will probably want to do the geometry once you get everything setup anyway,so your pushrod length will be determined then.

BTW, welcome to the forum.

Don

[topgun]

Thanks Don.

[pat mccarthy]

i have done the 460 drill and tap for the 7/16 bbc rocker stud s buy the bbf ford roller rockers and guide plates i drill and tap them on a mill .i check the push rods at mild lift and the geometry is dif for a harlan sharp to a crane things roller rocker are not all the same. like roller tip size and base circle and lift all play in get the rigth length pushrods

[Dave Severson]

A definite yes on stepping up to the 7/16" studs!!! Once you get the studs, some good rockers (I like Comp Cams), and the correct pushrods and guide plates as Pat suggested, might also want to stabilize all of it with a good stud girdle..... Big blocks like big cams, big cams take big spring pressures, big spring pressures take a strong rocker, stud, pushrod, and girdle. You don't need it all, but it sure does give some added longevity to the valve train....

[topgun]

Thanks so far guy's. But I thought early 460's like mine already have 7/16 studs. Can't I just bolt on a new set of studs and get rid of the bottle neck ones in there now and just bolt on the guides and rockers. I am not a huge motorhead so my knowlege is limited. My engine is aside from the bigger valves it has an edlelbrock performer cam and intake so you see it is not built to be a monster, Just a nice cruiser.

[Dave Severson]

If it already has the holes drilled and tapped to 7/16" then you save a bit on machining costs..... What pressure are your valve springs? The stud girdles are reasonably priced and serve to not only keep the studs all straight but will also help to maintain the valve adjustment.....

[topgun]

The valve springs are the stock ones but are all new.

[Paul Kane]

The valve springs are the stock ones but are all new.

Stock installed height of the OEMvalve springs is supposed to be 1.820", and the seat pressure is a measely 80 pounds or so. Hopefully you increased seat pressure slightly; otherwise do not expect this engine to rev much past 5000 rpm.

Since your installed height has not been increased, be sure to watch closely for the rocker body bottoming out on the stud even after you have determined correct pushrod length. There are a few ways around this if you have this problem.

Paul

[topgun]

The real reason I am looking at roller rockers is that with the new larger size valves I did not realize that the valve tip on the intake valve is shorter than the exhaust and causes a clearance problem with the rail type rockers which the manual states require atleast a 1/16 gap between the rocker and spring assy. The exhaust valves rocker to spring assy clearance is fine as it should be because everything is new including the rockers. So that is wht I am leaning towards the rooler rockers for a remedy unless the is another way to fix my clearance problem.....................Rich

[Dave Severson]

The real reason I am looking at roller rockers is that with the new larger size valves I did not realize that the valve tip on the intake valve is shorter than the exhaust and causes a clearance problem with the rail type rockers which the manual states require atleast a 1/16 gap between the rocker and spring assy. The exhaust valves rocker to spring assy clearance is fine as it should be because everything is new including the rockers. So that is wht I am leaning towards the rooler rockers for a remedy unless the is another way to fix my clearance problem.....................Rich

The roller rockers and paying very close attention to checking and measuring very carefully for the correct pushrod length is the best way I know of....

[topgun]

Thanks Dave. Sounds like I be gettin' rollers then. So will I just be able to bolt on a set of new studs and guide plates to install rollers? With mearsuring for correct pushrod length being the real trick? That part I have never done before But I WILL learn how. I hope someone here can help me with that info too.Thanks................Rich

[Paul Kane]

The real reason I am looking at roller rockers is that with the new larger size valves I did not realize that the valve tip on the intake valve is shorter than the exhaust and causes a clearance problem with the rail type rockers which the manual states require atleast a 1/16 gap between the rocker and spring assy. The exhaust valves rocker to spring assy clearance is fine as it should be because everything is new including the rockers. So that is wht I am leaning towards the rooler rockers for a remedy unless the is another way to fix my clearance problem.....................Rich

The different lengths on the OEM valves tips (between intake and exhaust) is the same as what you are seeing with the aftermarket valves. If you still have have the 0.0625" clearance between the rocker rails and the valve spring retainer then you are fine.

This spec exists because as the tip of the rail rocker wears, the rails get closer and closer to the valve spring retainer and may deperss the retainer and release the valve locks from position. If your rockers are not worn and you have plenty of clearance (between rails and retainer), then you are fine. That being said, a roller rocker valve train with optimized valve train geometry is still the better way to go.

Paul

[Dave Severson]

should be it.... We've been racing the BB Ford's since '97----balancing and pushrod length are IMO the two most critical parts of an engine build....

Use Pat McCarthy's method for measuring the pushrod length, it's the best way to do it.....

[topgun]

Pat McCarthy?