Need Some Help w/ Valve Train

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kultdouble
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Need Some Help w/ Valve Train

Post by kultdouble » Mon 27. Sep 2010, 09:58

Note: Complete or part of old conversation copied from the archives and brought back to you by admin. New replies can be added if desired.

Originally postet by "Andy "

Helping a friend of mine. To start we off stroked a 462 out to 418cid with 6.8 Eagle rods and custom Ross pistons. We then installed 2.19 Manley intake valves and 1.88 exhaust valves topped off with a tri power. The problem we are having is valve train noise. Not bad but enough to notice. I know with the different valves and the different cam the geometry has probably changed slightly. How much preload on the lifters is required? Or do adjustable rockers from an FE fit? Any help would be appreciated. Thanks, Andy.

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Re: Need Some Help w/ Valve Train

Post by Theo » Mon 27. Sep 2010, 09:59

Hi Andy,
The FE rocker arms interchange w. the MEL's. They have the same shaft diameter. Switching to 1:76 ratio FE adjustables is a very good idea. I didn't check the spacing, but I suspect that you're even able to install Harland Sharp roller rockers on a MEL shaft.Here's a copy of a message that I posted on the FE BB Forum 2 years ago. Check out what might be useful for you.

September 3 2002 at 2:38 AM Theo
(Login racecrafterFE)

....I think Bill Ballinger had a story either on an othjer board or on some free space he had. Some others followed by him and others on the orig. and this forum. It is about how to do the adjustments in the right sequence at a min. amount of time.
There are various ways to do it right. Got to jump off my desk now, so meanwhile I'll give you a copy of an old post of mine about the "how to find out about how many turns is needed for the correct lifter pre-load on a specific rocker arm. It takes into account the differences in rocker arm brand and adj./ non adj.
Hope it helps.

As a general of rule hydr. lifter pre-load should be ideally 0.020”- 0.060” on most popular V8
engines.
This figure is the distance between the lifter plunger’s position where it meets the upper lifter retaining clip (totally pumped up) and the position of the plunger after it has been pushed down by the adjusting nut at 0.020”- 0.060” into the lifter shell.. Before doing this adjustment the lifter needs to be on the cam lobe’s base circle (zero lift).
The ideal pre-load most often translates into a specific number of turns on the rocker arm adjusting screw. The # of turns varies from rocker-arm brand and engine brand.
If my memory serves me right I’ve put a ¾ turn on the H/S adjusters the last time.

You can find out how many turns will be needed to achieve the above ideal pre-load for your specific set up by measuring with the straight edge method. I learned it from a Crane manual, and I really like to use this method on a fresh engine w. new valve train components that I never used before. If your engine is block trued you'll usually have to do the following procedure only on one lifter to find out the right number of turns (adj. screw) on the rest of the rockerarms. Here’s how it goes.

With the lifter on the cam’s base circle and the rocker adjuster screw turned all out, the pushrod has just enough contact not to fall out of it’s position.
Then turn in the screw to make it just contacting the push-rod. This is the zero preload position.
Place a straight edge on the cylinder head’s valve cover rail so that it tangents the pushrod.
Scribe the pushrod at this meeting point w. a fine file or whatever you find convenient. Then scribe an other mark on the push-rod 0.020”- 0.060” over the first mark.
Start to turn in the adj. screw while counting the turns you’ll need to get the push rod meet the upper mark with the straight edge.
Now you found out the right # of turns you need to achieve the right pre-load on your specific application.

On NON-ADJUSTABLE rockers, the way to check for the right pre-load is to use a special tool or a water-pump pliers to grip the rocker and make it bleed off the lifter plunger all the way down to the bottom of the lifter shell. Not an easy job; so patiently give the lifter some time to bleed off. Once you feel that the plunger has bottomed measure the gap between the valve tip and the rocker tip. It should ideally measure 0.10-0.20”.
If it’s less, you’ll need shorter push rods. With too big a distance you’ll either have to purchase longer rods or trying to use rocker stand shims to compensate.

I recommend the use of adjustable rocker arms for the most accurate and easy adjustability. It surely pays off in every way.
Turn on
Best regards
Theo
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Re: Need Some Help w/ Valve Train

Post by Theo » Mon 27. Sep 2010, 10:02

I found one more of these.

......Usually .020" to max .060"..........
John, don’t turn the adj. screw till you feel a resistance. That’s not gonna work out properly for two reasons.

1. Some lifters might have less pressure than others. They’re mostly inconsistent. You won’t really know how much a weaker lifter has travelled its’ plunger down the shell until you feel that “resistance”. Add your # of turns and it will have too much pre-load in such a case

2. Even if you had a stiff lifter, it would take a while until you overcome the oil film slippage that naturally exists between the lifter seat and the push rod ball. Without even knowing it, you would create some pre load before you feel s.th.. If you add your turns in such a situation you might be turning it too tight.

Combine these two conditions and you get the picture of how far off your contact point can be.

While watching the push rod I prefer to turn in the adj. screw until it just contacts the rocker arm and until it won’t wiggle no more in the seat. Then I turn it in ¾ and I'm done.
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Theo
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Re: Need Some Help w/ Valve Train

Post by KULTULZ » Mon 27. Sep 2010, 10:02

I think the most important thing to consider and establish on any engine is correct valve train geometry. Any number of factors can vary it including design/assembly mistakes and service procedures performed since factory assembly. You also have to consider valve spring installed height/coil bind and other factors to arrive at a successful assembly.

http://www.compcams.com/information/Products/Pushrods/

The procedure for collapsing lifters (special service tool needed) and measuring valve lash is described in your MEL engine manual. This will be your first step in arriving at proper geometry. Also early MELS were plagued with valve train problems, but most were addressed by the 1959 production run. This is another consideration that has to be taken into account.

The FE adjustable rocker arms are interchangeable to a MEL, as are the tappets (be sure to include mechanical style push rods). The adjustable rockers will also give you a lift increase of 1.76 as compared to 1.73 for non-adjustable.

Factory Method Of Installing Adjustable Rocker Arms On A Hydraulic Camshaft –

Position the No. 1 piston on TDC at the end of the compression stroke. Bleed the hydraulic lifter for each valve to the fully compressed position. Adjust the locking nut on the end of the rocker arm to obtain a clearance of 0.110” -0.210” at the valve. Repeat this procedure for each cylinder by turning the crankshaft a ¼-turn at a time in the direction of rotation, while adjusting the valves in the firing order (1-5-4-2-6-3-7-8).

Operate the engine and check for rough engine idle or noisy lifter(s). Tight valve clearance causes rough engine idle. Loose valve clearance causes noisy lifter(s).

Source- FORD MUSCLE PARTS CATALOG

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Re: Need Some Help w/ Valve Train

Post by KULTULZ » Mon 27. Sep 2010, 10:03

Any Possibility Of Your Sharing The Assembly Details of This Engine?
I assume you meant 518 CI. Is it an OEM intake or EDELBROCK? What type of carburetion? Who offset ground the crank and how did you arrive at the proper connecting rod length/piston pin height? Are the conn. rods custom made or from another application?

Were the MANLEY valves custom made? MEL stem lengths are a little shorter than FE. Did you allow for this? It may be the cause of your valve train noise.

What type of cam are you running?

Curious here...

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Re: Need Some Help w/ Valve Train

Post by hawkdouble » Mon 27. Sep 2010, 10:04

Originally postet by "George Sebastian "

Crane have adjustable rockers available. Specify for a 428 CJ engine!!

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