valve guide !!??!! help

[01boneless]

ok so i went and picked up a new valve guide and the mechanic said id have to shim or grind the guide to fit the head or valves or somthing. i asked him if he meant relaping he said no this is a whole other thing. any thruth to this ? iv never heard of it but IDK now im realy confused?

[CJM]

They are pressed in, my buddy puts them in be heating the heck out of the head inside an oven at like 250F and freezing the guides. Then quickly takes them out and pops them into place and your done.

Its not something your average guy can do, also if this is the same mechanic you been using its time to seek another one.

[01boneless]

i know how to put them in put there saying in order for my valves to fit in the new guide it has to be reamed out and then i look in my clymer and it says you need a valve reamer to ream them out he** i thought you just put the dumb guide in and you valve would go in it ? somebody please help

[CJM]

Never been that far before, not sure tbh.

[01boneless]

NOOOOOOOOOOOOO!!! lol anyone else? if i take a pic of my old guide will the help?

[matts27]

Press the old guide out, mic (measure) the old guide for length, width, height, seat. Compare to the clymers and what you have meaning the new one. The outside of the guide should already match your head also the guide seat and height should match too. Now, the clymers should give you a valve stem diameter with a tolerance limit. Check your old valve to this diameter, also a good time to check the valve seat width (contact area) because you don't wanna match a beat valve to a new guide.

The valve stem has a clearance to the guide, believe due to expansion rates and such. You need to compare the inside of the guide to the valve stem, this should be real close to the new valve stem. I've never had to ream a guide, you would obviously need a reamer because the inside has to be perfectly smooth and round or the stem will get nicked and wipe out the seal.

I would think if you have a new Honda or guide aftermarket guide it should already match up to stock valve stems and heads. Just thought I'd give you some advice, if it does need to be reamed I'd bring it to a machine shop and knock out the other 3 whiles it's there. Hope this helps explain the process a bit, Matt

[01boneless]

i probley know the answer to this but will it hurt to tap it in the new guide because i think the reason it looks to big is because the end of the valve where the clips go is fatter a little. every shop ive talked to says it shoudent need to be reamed unless i have over side valve whitch i dont recon i do?

[matts27]

Heat the head in the oven, then press it by placing something soft (block of wood) against the guide and tap it in that way. Oh, freeze the guides for like 4-6 hrs. Work quick when the head is hot, should get 'em in about half way then tap in with a soft mallet/dead blow hammer, use the block when near the end. My experiences have led to me changing the valve with the guide, meaning usually the valve is at the limit or gashed from the bad guide. Good luck and hope this helps a bit, measure everything very carefully, Matt

[01boneless]

ok guys i know how to instal the guids im just saying my valve wont fit in the new guide so how to or do I ream it and where can i get a reamer?

[tri5ron]

Your engine will probably be better off if you have an experienced Machine shop do the work, rather than you just "taking a shot at it" and hoping it comes out correctly.

Also, you can ask them if you can be present when the work is done, so that you can watch and learn the process for future reference.

Seeing it done by a professional, and being able to ask questions, get answers, etc., will be a good learning experience, that you will remember for the rest of your life.

Having the knowledge of doing it properly, will help you to understand the "Whys" and "Hows" of mechanics and engine maintenance.

[matts27]

Originally posted by 01boneless
ok guys i know how to instal the guids im just saying my valve wont fit in the new guide so how to or do I ream it and where can i get a reamer?


These Honda OEM guides, read they are undersized and need a reaming to just open up slightly. If you can I'd return them and search some powersport stores or call a motorcycle shop/machine shop and get some aftermarket that will be ready to go. From what I understand the guides need to be honed after they get reamed too. Don't know why they need a honing but when I was building motors remeber reading about the proper way to adjust guides, but all I dealt with went in perfect, never had this problem with undersized guides. Matt

[01boneless]

so are after market guides already reamed? like kibble white or could i just take this guide to a machine shop and have them bore it out and hone it lol ( to a 426 haha) :devil:

[matts27]

Found this for you...

http://www.thumpertalk.com/forum/archive/index.php/t-418639.html

Explains where you can find the reamer, couple different places, I would call someone and ask what they use for guides, seems like a lot of work for a standard size part. I would think Honda would run tighter tolerances with all there history of reliability and well made motors. Interesting how this is, meaning the guide is too small. Keep us posted if you find anything, I would think the aftermarket would be set and ready to go!!! Matt

[01boneless]

thanks so i called around and every one thought I was a idiot lol ill see what i can do but i hate to order aftermarket because i want to ride lol i can get a reamer for the size 5.5 but how would you hone i think ill ream it or take it to a machine shop and see what they say lol this is freakin crazy lol

[DnB_racing]

Originally posted by 01boneless
ok so i went and picked up a new valve guide and the mechanic said id have to shim or grind the guide to fit the head or valves or somthing. i asked him if he meant relaping he said no this is a whole other thing. any thruth to this ? iv never heard of it but IDK now im realy confused? lol!!!
now you get the understanding as it why it costs so much to totally rebuild the heads, there are all kinds of specialty tools and tight tolerances involved,

its nothing that a good machinist cant do, or a real patient home mechanic. but most wont take the time to do it right... dont rush!!!

measure it 3 times and measure again... I give you credit, most would have given up and sent it out by now.. im not sure if its stubbornness or just a thrill to learn new things,

after installing the guides measure again and check them to make sure of correct specs, there is a very good chance they will need to be reamed,you wont have to hone,as long as the reamer fits, just ream with plenty of cutting oil, and clean real good before assembly
but if you get that far then its only another step, also make sure you mark the new guide to exactly the right depth before freezing in dry ice, i would personally get the guide driver, instead of wood but that's your call

what type of valves are you going to use, after this much work im sure you know its not even worth using the old ones, you might as well give it a complete rebuild

it would be a shame to have to do a tear down again next year cause of a bad spring or another guide or valve... do it all right this time and be proud of a self built complete new head..

make sure your head is not warped before starting all this work. and check when done,

good luck and dont overlook any thing that might bite you next year:)

[01boneless]

yeah im wanting to learn and ride to lol so in stall the guides check the measurments then if to small ream it to 5.5 (manual calls for ) and should be good ? now can i take the guide to the machine shop to have them ream it or shoud i have to instal it first lol would have been easyer to but aftert market guides lol also im useing oem valves (KCY)

[DnB_racing]

Originally posted by 01boneless
yeah im wanting to learn and ride to lol so in stall the guides check the measurments then if to small ream it to 5.5 (manual calls for ) and should be good ? now can i take the guide to the machine shop to have them ream it or shoud i have to instal it first lol would have been easyer to but aftert market guides lol also im useing oem valves (KCY) dont ream it until its installed to the right depth and cooled to normal temp,,, use more cutting oil then you need and go straight and slow

[01boneless]

how do i know when its in the right depth when it stops and seats? also all the other guids are perfect (yes i measured) so if i put it inthe oven will it ruin those seals in the guides?

[DnB_racing]

Originally posted by 01boneless
how do i know when its in the right depth when it stops and seats? also all the other guids are perfect (yes i measured) so if i put it inthe oven will it ruin those seals in the guides? measure the old guide before you remove it and mark the new to the same depth just to be sure!!

after installing the new guide, and head is cool run your reamer through the other guide, to clean any carbon cooked off the old guides, and measure again to be sure of there tolerances. then install all new seals, seals are cheap


remove all the other valves and seals before putting in oven

[01boneless]

ok so i put it in the oven and they wont come out any ideas?

[DnB_racing]

Originally posted by 01boneless
ok so i put it in the oven and they wont come out any ideas? heat to around 275 degrees if you use the actual guide driver you can hit it pretty good without it mushrooming, but if using the wrong driver it could just flatten it out and you will cause more damage trying to drive it out

[01boneless]

well im not useing a driver lol i heated at 300 for about 10 min ? i was useing a screw driver handel because it wont mess them up lol im working late haha

[bcleveland]

I thought I would try to help you. Im fairly new to quads, but build my own racing kart engines and a few others locally. 99% of guides will have to have a finish fit put on them. Some need a reamer some just need a guide hone run through them. This is a very touchy area to be messing with. On a kart you run minimum .003 clearance between your guide and valve stem. If clearance is to tight when the engine gets hot the valve will stick most likely in the open position. This being an over head valve motor that means you just busted a piston, bent a new valve, and most likely cracked the guide boss in the head. Also a reamer will never leave a quality finish no motor how hard you try. Thats not what it is made for. The reamer is used to give you a close but not exact size so that you can use your guide hone to work the clearance .001 at a time untill you get where you want to be. Also heating the head is not gonna make the guides just fall out. That engine gets hot everytime you run it and they stay in. I agree heat it in the oven not to high aluminum will warp on you, and then tap them out or use a press. The press is deffinately the recommended way so that you get even pressure on the guide and not just sharp fast blows. I hope this helps.

[01boneless]

ok well i called a machine shop and they said they can press the old out and put in the new and ream it to 5.5 for 10 buck i figure you cant beat that .?
after all this this hundy better no smoke :mad:

[powerbomb400]

If all they are charging is 10 bucks it won't take them long to do it. But they do it all the time and that does make a world of difference.

[01boneless]

ok so i was looking at the valve and it looked slightly bent so i just bought a new one so every thing at that port will be new exept springs :D

[01boneless]

update!!
so I went to pick up the head at the machine shop and they did not put the new guide in like I had asked them to the just re reamed the old guide and said they all measured the same so i got a new valve to put in should i still have the guide put in (i think they was just being lazy) lol

[CJM]

IDK, cant physically see it-but if they measured it and can show you its the same then your good.

Course a 2nd opinion is always a good idea too.

[01boneless]

true but i already have the new guide i did not see the measure ments so idk probley have it pressed in to be on the safe side

[DnB_racing]

Originally posted by 01boneless
true but i already have the new guide i did not see the measure ments so idk probley have it pressed in to be on the safe side ya I think i would change it,,,

you said you found a bent valve, so maybe the part that was measured by the shop wasn't worn,

but my guess is that the worn part is from the valve riding in the guide and egg shaping it like you mentioned...
it might not be worn the entire guide, but just part of it, and that wont last before it will be needing service again

but like was mentioned get another shop to check it, and make sure they check it in seveal places, not just the center

[01boneless]

ya like i said i got the new one so id might as well replace it cause my luck if i dident id have to tear back down again. and im still not so sure this stuff will fix it ?

[DnB_racing]

im pretty sure the combination of the bad valve and guide will cure the problem...you all ready know it was just that one side that leaked,

just double check your spring specs before installing,

and make sure to assemble with tight wound side of springs go toward combustion chamber

[01boneless]

tight wound toward the combustion chamber lol never heard of that i usaly just put the springs on lol please explain this couldent be my prob im sure right ? lol

[DnB_racing]

Originally posted by 01boneless
tight wound toward the combustion chamber lol never heard of that i usaly just put the springs on lol please explain this couldent be my prob im sure right ? lol it will change the spring rating if not done in this way

[01boneless]

so what will that hurt lol how do i tell what side has more tighteness lol thats not a word haha tention there we go

[DnB_racing]

more wraps in the first half to 3/4 inch ,

if not it can cause spring bind

[01boneless]

ok thanks bud i appreciate all the help

[01boneless]

ok so i was bored because the head was out at the machine shop so i checked other things out. lol so i taped out striped holes and stuff lol now i did i did notice my piston had a little play in the cylinder good or bad? every one says its supposed to have a little id say it has (estiment) .014 on the feeler.

also i now have the most costly set of valve seals lol 12.00 for 4 lol :eek:

[blacknblue#2]

.014 seems like alot but i could be wrong. Im thinking most engine builders shoot for about .007 but dont quote me on that

[CJM]

Best thing to do is check the ring fitment in the bore. IIRC wiseco is .014 and .017 inches.

You can fit a larger feeler than that you got an issue.

[01boneless]

oh ya bro the ring to cylender is like .006

[CJM]

That seems awfully small, but I never measured a stock bore tbh.

If you go to wisecos website you can find the instructions (if you dont have them) where you multiply the bore size by a certain number and thats your proper ring gap. Id do it to be sure.

[01boneless]

i calls for servise at like 12 so ill check for sure but like i said im not sure just trying to rember lol

[CJM]

np, just trying to help ya out.

[01boneless]

well the DB at the machine shop said he can get it pressed out and he is going to have to cut it out and he is afraid of it so any suggestions?

[powerbomb400]

He couldn't heat the head and then press it out?

[01boneless]

nope he said he beat it to death never heated it though i dont think he knows what he is doing!

[CJM]

What machine shops and people are you taking this stuff too? He BEATS it out your gonna have a MAJOR problem.

I tell you what, before he ruins it go get it-refuse to pay and send EVERYTHING to CD racing (site sponsor) so they can do it right for you!

[powerbomb400]

Its a aluminum head so it would expand quickly. Grab that thing and run with it. Do what CJM said and sit out a couple of weeks. I would think if it was froze up he could put it a solvent tank and soak it being a machine shop

[01boneless]

im goign to get that b**** out and heat her up for 15 min in an oven drill the guide out half way put a punch in the and punch it out lol thinker not a stinker haha DnB where you at lol

[01boneless]

Originally posted by CJM
What machine shops and people are you taking this stuff too? He BEATS it out your gonna have a MAJOR problem.

I tell you what, before he ruins it go get it-refuse to pay and send EVERYTHING to CD racing (site sponsor) so they can do it right for you!

lol it seems its hard to find a good mechanic or machine shop around me dont it lol If someone who knew anything would start up a shop they would make a killing :devil:

[CJM]

Id say so,. Maybe I should move there and open a shop.?

[01boneless]

we will be bussiness partners lol lol i called a good machienest ( i think lol) and he said to get it out of there and drill half way down the guide and stop leaving a lip and heat the head it up and put a bolt catch the lip and drive it out thus eliminating the chance of sliping and hiting the head ?

[CJM]

That sounds much better than the other guy.

[01boneless]

well i have the head at a machine shop (the good one) and they are going to put in the new guide but they cant ream it because they dont have the right size reamer. so i called menards and they have the right size but will it work or does it have to be a special valve reamer?