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hangon
11-16-2004, 11:02 PM
I just rebuilt an 84 evo. I have 300miles on it and now the front rocker box is ticking loudly. Do you think I may have broke a valve spring?

junior
11-16-2004, 11:06 PM
if it is a fresh rebuild, you may have some crap caught in the lifter screen. pull it out and check, then let us know...

j

rwpatton
11-16-2004, 11:08 PM
Hangon, are your running adjustable pushrods?

Sounds like loose pushrod or collasped lifter(trash in it maybe).

Let us know.

RW

hangon
11-17-2004, 02:17 AM
I cleaned the screen again and it looks good. I adjusted the pushrods out another half turn with no change. The lifters are 20 years old so I have some new ones on the way. I will blow out the holes in the blocks prior to assembly and hopefully I can drop the wrenches And grab some throttle again. Thanks Man

Soretailcat
11-17-2004, 04:34 AM
Hangon,
The lifters used in the 84 and 85 are different from the other Evo lifters thru 97. They were discontinued because of problems with bleed down. You may have an air bubble in one of the lifters. If it continues to hammer, you can usually tell which one by placing a finger tip on each of the pushrod tubes...you will be able to feel the vibration in the tube of the offending unit, stop the engine and let it cool down. Rotate engine to TDC or firing mark on compression stroke. Remove or collapse pushrod as much as possible. Take a piece of stiff wire and push through the oil hole in the top of the tappet...you will feel something move..hold the wire in place and take a small screwdriver and push the top of the tappet, that you have the wire inserted, down until you collapse the tappet. The spring below the tappet piston will push it right back up. Readjust your pushrod, crank it up and give it a while to pump up. That may clear out the bubble. The wire through the oil hole trick will not work on 86 and up tappets. This costs no money, is easy to do and may solve your problem. Let us know how you come out.
Soretailcat

Ratbike
11-17-2004, 04:47 AM
Soretailcat.

Wow you ARE good. Some great advice there. I always like to read your posts.

:)

junior
11-17-2004, 06:35 AM
agreed....

s.t.c.....you da man!

j

Relic
11-17-2004, 11:41 AM
Man, if those lifters are 20 years old, I'd just put in new ones. :)

Soretailcat
11-17-2004, 12:58 PM
Thanks for the complements, guys. It is just that I have been machining on HD engines for several decades, and constantly trying to make them better,faster, and more reliable.........."even a blind hog finds an acorn once in a while."
If all else fails, and it is a tappet related problem, take Relic's advice.

BTW, any of the OEM or aftermarket tappets,for the evo big twin, will work.

IMHO, the 84 and 85 evo engines were the finest big twin engines ever produced by the motor factory, for reasons I'll cover some other time.
Soretailcat

wreckerman
11-17-2004, 10:31 PM
scoretailcat if memory serves me right i think the 84/85 eveos used a thinner head gasket on them gave them a little more get up and go same as shaveing the heads

Wide
11-17-2004, 10:34 PM
I just read in ahhh of the masters :D

junior
11-17-2004, 11:04 PM
scoretailcat if memory serves me right i think the 84/85 eveos used a thinner head gasket on them gave them a little more get up and go same as shaveing the heads

what i recall is that the cases were actually stronger in these years due to both superior metallurgy and a webbing that was discontinued in later models....

j

wreckerman
11-17-2004, 11:35 PM
junior i do also remember the cases

Soretailcat
11-18-2004, 12:49 AM
Wrecker,
Harley changed the head gaskets, used on the evo big twin, about 4 times, if my memory serves me correctly. All of the big twin gaskets have been .062", and the later XLs have been .045". Harley has been known to make running changes and/or use something different for a while and not list the change. I would not be surprised if HD didn't use some 1200 XL gaskets on the big twin. Of course there was no evo XL in 84 and 85. Harley also published incorrect torque specs for the early evo. They listed 28 ft.lbs as the head torque. They issued a memo after that to use 40 ft.lbs. I have used that ever since.....ie..torque to 8 ft.lbs, then 16, then 25, then 40, using the recommended sequence. I have built many big twins using .045" thick head gaskets. They will give a few tenths of a point increase in compression but the real benefit is closing up the squish area which makes the engine more efficient.....your heads have to be nice and flat though.

The 84 cases were simply the old shovel cases redrilled for the different cylinder studs. They also had the old cast in steel main bearing sleeve that was heated before the aluminum was poured into the casting. The heating of the sleeve prior to pouring in the aluminum gave a better grip on the sleeve. In 86 Harley changed vendors and they poured the aluminum into the molds with the sleeve at room temperature. The metal would not adhere to the sleeve as well, consequently the main bearing sleeves would loosen and cause major problems. I have a repair for that if the case hasn't been wallowed out too badly. In 90 they did away with the steel sleeve altogether seriously weakening the cases. That is why so many of the 90 and up evo big twins cracked cases, leaked oil around the cylinder bases in a short time, short piston and cylinder life etc. Harley recommended in a service memo that if the Timken bearings, (left side main bearings) were changed more than twice, get new cases....they don't grip the bearing cups tight enough. If the cups are not aligned perfectly when replacing them they will shear aluminum cocking the cup and increasing the preload on the bearings. They will howl like a mind blown werewolf and eventually fail. There were also many changes in their flywheels, rod bearings (weaker), pinion bearings etc.from 87 up, I won't get into at this time. I personally will not build an engine bigger than 89 inches and highly recommend no big bore cylinders on 90 and up evo cases. The right side case on the rear cylinder will have almost no gasket surface after boring even for 3 5/8 cylinders. They will leak and/or crack.
My fingers and brain are getting tired.
Wide, did you just flame me?
Soretailcat

junior
11-18-2004, 02:52 AM
that post is a keeper. i am going to copy and paste it somewhere...

j

rwpatton
11-18-2004, 04:00 AM
That's It! :P

I've had it. B)

I'm going to Georgia and visit STC.

Don't know when, but in the next year your gonn'a see my ass.

Gott'a check your shop out and you. If you drink tea or beer don't matter cause it will be fun.

HCG run to SORETAILCATS place.

Now look what you have done.

Like it or not, you have become a destination. :lol:

RW :D


Or you can tell us "NO" B)

wreckerman
11-18-2004, 11:30 PM
rw i will ride down with you for that besides i think he is are age so we will have a lot to talk and drink about when we get there

84blockhead
06-09-2013, 04:04 PM
I (http://I) just rebuilt an 84 evo. I have 300miles on it and now the front rocker box is ticking loudly. Do you think I may have broke a valve spring?[/QUOTE]

I hate to revive an old thread but Im having the same problem,,did u ever figure out what was causing it? here is a link to listen to it http://www.youtube.com/watch?feature=player_embedded&v=teU_8UKh04w