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View Full Version : Ironhead heads, valves, springs guides, piston/cylinder spec and manymore things, need to know


1982ironhead
18th October 2009, 19:57
test rode it today and didnt go more than a mile, i had a motor issue running around a hundred mph a week ago and am still having the same problem, it acts very much like it is WAY too rich at 3000 rpm, that is as fast as i went today and it ran ok below that, going up a hill it pulls better than the Q cam even in the low RPM's.

checked the oil when i got back, sounded like the bad noise i heard a week ago, possibly the rocker arm or or something not real loud though.

oil was dark and more metallic than i like to see, pulled the front head ( the banging i heard over the motor running at about 100mph definitely came from up front somewhere and killed power) the valves look excellent, not sure how to check the play and get an exact measurement, but i could wiggle them once i pulled them out about an inch or so. i definitely have hardened steel seats, so sometime in the past it had a valve job, and by the condition of the heads when i first tore into it in april, id say not too long ago.



i have play between the cylinder and piston, between the cylinder and piston with the feeler gauge seated on the top ring there is .012" and what im worried about is that i can tweak it a little, probably between .002-.005 left to right and i dont know if there is a spec for this....



the cylinder wall looks GREAT still no dings or dents in the valves or piston top, no scoring on the cylinder walls.


tried to go faster than 3000+/-rpm in 1st and 4th, wouldn do it, almost acted like i was running a , idunno like an 74 or however high they go. not the carb though, same exact feeling as it had running a 66 when something went BANG BANG BANG about 10-15 times before it stopped getting beat on.

maybe a broken ring? i wouldn't have 180 psi though if thats the case. im kinda stumped.

i do need to check valve/guide tolerences though, and the springs, to see weather i need spacers for the Y cams, which seemed to do great without spacing.

BuckIRyder
18th October 2009, 20:18
Sounds like you need to tear the top end down and gauge everything with the proper measuring tools to figure out once and for all. The FSM will provide the appropriate clearances and tolerances.

1982ironhead
18th October 2009, 20:27
going a bit at a time, trying to figure the loss in power first, did the last top end only 7000 miles ago in april

1982ironhead
18th October 2009, 20:56
shouldnt be any side play to the piston though right? im thinking bushing in the connecting rod since i didnt replace it before, guess ill pull the cylinder too and check the rod bearings

natez1
18th October 2009, 22:18
0.006 in. is the wear limit for piston to bore, measure the piston, measure the bore the differance should be less than 0.006 in. Did you check your wrist pins, seems to be a common misinstalled item. Rocker arm clearance could make the noise but uncommon. Did you check valve spring tension when tore down? Rod play? Last I had a horrible noise on my rigid which I swore was top-end, turned out to be the rear chain tapping the gaurd! good luck keep us posted

meanmechanic
18th October 2009, 22:53
Ignition system is good? 180 psi suggests good comp but what is it dry w\o oil? Without looking at stuff myself, the plugs could be the wrong heat range (too hot) and could cause that stuff to happen at high rpm. After you slow down the plugs start firing again. What could help is when you take it out for a run, take it up to where it cuts out, makes noise and such, pull in the clutch and shut off the ing and pull over. Pull the plugs and look at them for a good read. Of course the bike is apart now, right? Keep looking, the prob will rear its head eventually and you'll catch it .

1982ironhead
19th October 2009, 00:09
Did you check valve spring tension when tore down? Rod play?


i dont have the tool to check valve spring tension, and what rod do you mean?

*so far i have pulled the head and cylinder on the front cylinder.*
-absolutely NO blowby on the piston skirt
- there is side to side movement of the connecting rod and piston but NO up or down play, good tight bearing down there(crank/connecting rod).
- hardly any discernible play(trying to tweak it in a circular motion) between the piston and connecting rod, suggesting the bushing is good on the wrist pin.
-cylinder is in great shape
-no metal flakes or wear marks in the bottom end
-intake and exhaust valves are both under .0025 play
-valves look excellent
-great looking hardened valve seats
- guides look fine
-springs look stock but not bad looking, collars and keepers look fine also, keepers were replaced at last top end, andrews.
-rocker arm bushings and rocker shaft are all fit well, couldnt even get the .0015 feeler gauge in
-rocker arm-arms look fine, no abnormal wear or cracks, again, no metal flake here.
-all oil lines are clear
-oil coming from where the filter screws on was dark and metallic, also what is in the tank ..but only 350 miles old.


what else to check?

1982ironhead
19th October 2009, 00:16
Ignition system is good? 180 psi suggests good comp but what is it dry w\o oil? Without looking at stuff myself, the plugs could be the wrong heat range (too hot) and could cause that stuff to happen at high rpm. After you slow down the plugs start firing again. What could help is when you take it out for a run, take it up to where it cuts out, makes noise and such, pull in the clutch and shut off the ing and pull over. Pull the plugs and look at them for a good read. Of course the bike is apart now, right? Keep looking, the prob will rear its head eventually and you'll catch it .
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yes, ignition excellent. 180 was with a shot of oil, it had sat a week since i took it apart( ordering and installing cams wait period)
plugs are the same i have used the last 7000 miles autolite 4123's
yah the bike is apart now, i rode about a mile after i let it warm up, was gettin funky around 3000 rpm, rode there trying to use the enrichener an fiddle with adjustment, listen for the noises, and was back and parked it about a minute later, coming in off the main road in the 2500 rpm rang and up the drive in the 2000 range, so yah the plugs wernt a great read for the problem area, but they look perfect, nice light tan color


the ignition and carb are always possibility's as far as the power loss but they will not make the noises i heard and the advance weights didnt explode, the carb and ignition also wont turn my oil a few shades darker and a lot shiner in 20 minutes.

bustert
19th October 2009, 00:42
if this was a new cam install, the coil bind should have been checked before the rocker boxes were installed. if they are binding, the lift would be reduced but worse still, you could be putting one heck of a side load on the valve stems.

stock rockers drag front to back on the valve stem and if the coil is binding, this will have a tendancy to push the stem from under the rocker in its mild condition, but if bind is worse, broken springs, bent valve stems and worse a dropped valve which could take out the crank and cases!!!! roller rockers prevent this by causing a straight line drag as the roller moves across the stem.

180 psi with .012 piston clearence is odd so it leads me to believe that the intake valve is closing too soon which would elevate cylinder pressure unless you are running high comp heads. might check cam timing, just one tooth can make a big difference.

1982ironhead
19th October 2009, 00:52
i was trying to edit my last post and got kicked offline.....


ill prolly put in new gaskets, new rings, *MAYBE* go with new springs and set up the valve train better for the y cams(not the cause of my issue, i put them in AFTER the issue) and an oil change again..... maybe pull the oil filter and flush the system and feed in a few quarts of fresh oil?

i still have it apart and will for at least 2 days untill i get the rings, springs and other things. i am gonna go look it over, stare it down, read the book a few times over.....

oh, i checked the piston/cylinder clearences again, and cannot even get the .0015 in, i was checking in a useless spot before, it has a lip on the edge of the piston, i had to pull the top ring for a good read and its still tight, about the same movement as i had in the valves/guides, just enough to feel, not enough for me to measure.

1982ironhead
19th October 2009, 01:03
if this was a new cam install, the coil bind should have been checked before the rocker boxes were installed. if they are binding, the lift would be reduced but worse still, you could be putting one heck of a side load on the valve stems.



how do you check coil bind with the rocker box off? the rocker arms are in the rocker box, but then you cant see the coils....! im gonna check clearence in the vice, total length, cam lift + .060.... its on the andrews site, i have it printed out, gotta find it

bustert
19th October 2009, 01:07
the best way to check piston/cyl is to use a inside bore gage and check cyl in atleast three spots vertical and another set 90 degrees from the first. use outside caliper and do the same on the piston. subtract the piston from bore for reading. feeler gage is not accurate.

1982ironhead
19th October 2009, 01:12
hey that would be a better way to check valve/ guide and rocker shaft/ bushing also.

i bought a new set of feeler gauges friday and was jus itching to use them i think

bustert
19th October 2009, 01:13
the answer is simple. you know the rocker ratio and you know the cam lift. take a spring height measurement with valve closed. use a spring compressor and colapse the valve all the way. subtract the difference and you will have valve travel. subtract calculated lift from valve travel and this will be the coil clearence.

bustert
19th October 2009, 01:18
would be rough to find that small of a bore gage, just use a dial indicator on the stem with no spring, hold valve up in it's seat and take side reading.

1982ironhead
19th October 2009, 01:21
http://i390.photobucket.com/albums/oo345/1858rem/100_1181sml.jpg


here is the piston, looks pretty good still (cleaned some carbon off the top though

1982ironhead
19th October 2009, 01:27
and another.. had to downsize to 33% to get em to upload quicker.
http://i390.photobucket.com/albums/oo345/1858rem/100_1182sml.jpg


the head

http://i390.photobucket.com/albums/oo345/1858rem/100_1133sml-1.jpg

1982ironhead
19th October 2009, 03:30
miked cylinder,3.2005 at the base at three different cross sections, calipers are not big enough to measure the piston, but it is a .010+ and has hardly any wear on it.

valves to guide,
exh valve-.3400 guide-.3415
intake valve-.3090 guide .3105

why are the intake and exhaust valve stems different diameters?

spring assembly including collars, uncompressed
intk-1.6400
exh-1.6700

compressed fully (dont know if this # is important)
intk-1.025
exh-1.025

spring only uncompressed length
exhaust inner-1.331 outer-1.477
intake inner-1.3235 outer- 1.465

collar thickness
intake top collar-.097 bottom collar-.059
exh top-.097 bottom-.059

meanmechanic
19th October 2009, 18:23
Just saw the pics, maybe its the camera but the plug in the head is white not tan. The pistons look like Keith Blacks so timing is retarded as they specifiy? Years ago(30) I ran a chevy 302 all cammed up, you know the works, I would only get 2 weeks out of a set of plugs. High rpm misfire would set in and you'd think all h*ll had broke loose. Change the plugs and all was well again. At the track I ran 2 ranges cooler plugs.

1982ironhead
20th October 2009, 01:22
Just saw the pics, maybe its the camera but the plug in the head is white not tan.
that is running a 28/70 jetting on a S&S E, normally burns very clean, looks like new for the first few hundred miles really.

The pistons look like Keith Blacks so timing is retarded as they specifiy?

yes, keith black pistons, and no, not retarded the 2-3* as specified, it runs about 180-190* oil temp on a warm day and get absolutely no predetonation.

the noise i heard was not predetonation, it killed power, bringing me from 5000+rpm to 4200rpm very fast, (i was at the time testing out a 66 main jet) after the noise quit i tried to speed back up and had no more power, slowed down to turn around and head back home and got a single backfire, almost thought it was gonna die or size up, kinda picked back up though, rode home around 2500-3000 rpm ok, started surging before i got to the house, tried the enrichener thinking i was too lean, it did help some, then i remembered i need to go get gas and had prolly just hit reserve, switched to reserve and it was fine. got home and checked the oil it was still greenish(new looking) with some metallic, not bad, decided to change the cams from Q to Y and check the old gears,gennerator and stuff,(this is when i went from the 66 jet to the 70 jet) looked fine installed fine, no weird noises on startup, next day noticed a light taping in the rocker, figured i might need spring spacing, decided to test ride it anyhow, seemed to run pretty strong at first, rode up the mtn and even pulled better than the Q cams uphill at 2500-2800 rpm, on the way back down i decided to see how it pulled, slowly built it up to 3000 or so and was gonna gun it and it bogged out right as i hit the throttle, so i took it easy in 2nd 3rd an4th till it straightened out and decided to try again, in 4th, no power after 300-3100 rpm. i let it idle about 10-15 minutes Saturday night after getting the cams so i could set the fuel air and other things, the next morning(yesterday) i went for the short ride, maybe 10 minutes total...... when i got back my oil was definately a lot darker and more metal in it, and i still dont know why. this was yesterday

madfox22
20th October 2009, 16:16
You seem to have a little too much installed spring height. Stock height is 1.281 on the outer spring when measuring the spring coil only. You said your intake (uncompressed height) is 1.640. If you subtact your upper and lower collar thickness, I come up with 1.484 on the installed spring height. That is approx .200 too much for stock springs. I say stock springs, could be your not running stock springs ?
Anyway, what I'm thinking is this. Check your installed valve stem height by removing the springs and meausuring that distance. If this is excessive the bottom side of the rocker arm could interfere with the upper spring collar, and cause the some problems like valve floating, keeper loss, and some other major stuff. The installed valve stem height being excessive, combined with the higher lift Y cams could cause your problems.
You may or may not be able to see a spot on the rocker arm or the collar where they are interfering by looking at them.
Be careful who you get to do your valve jobs, alot of people tend to overlook important things like I mentioned.

Gone
20th October 2009, 19:16
when u say metal, do you know what kind of metal? is it steel, aluminum, or bronze? if you keep getting what you describe as a significant amount, i would think the source would be readily apparent.

1982ironhead
20th October 2009, 20:06
not installed height, just enough tension on them to hold them lightly in the vice, ill go check the stem height and installed height in a few minutes.

when u say metal, do you know what kind of metal? is it steel, aluminum, or bronze? if you keep getting what you describe as a significant amount, i would think the source would be readily apparent.
__________________

not sure on the type of metal, ill stick a magnet in the tank and see, certain its not brass though, either aluminum or steel.

1982ironhead
20th October 2009, 20:11
The installed valve stem height being excessive, combined with the higher lift Y cams could cause your problems.

my origonal problem happened before i put in the y cams, the banging at high speed, it only occured once, and i did not go that fast after it happened to try and reproduce the noise.



i dont know if i really need a valve job, everything is in spec, need to re measure the exhaust valve stem and guide since i think i wrote the #'s down wrong .3415 and .3400 oversized?