Jump to content
Sign in to follow this  

valve seat problems

Recommended Posts

so my buddy who works at factory connection got me faction mx ss valves with springs and retainers for $100, and i sent my head out to a guy in massachusets "harry's machine parts" he does honda head work, and he told me my ss valves wont work with stock seats, and i need to get my seats removed and have bronze ones put in

is this true?, or can i just get away with my 04 valve seats recut :thumbsup:

thanks dp

Share this post


Link to post
Share on other sites

your better off putting any year stock new head and valves on it , and a G1 cam with 44 lb intake springs....it will last longer , cost less and go faster...add a 13.5 piston if your good with race gas only!..38 hp...easy stuff.

Share this post


Link to post
Share on other sites

your better off putting any year stock new head and valves on it , and a G1 cam with 44 lb intake springs....it will last longer , cost less and go faster...add a 13.5 piston if your good with race gas only!..38 hp...easy stuff.

Share this post


Link to post
Share on other sites

see i cant afford a new head, i was going to get rhc valves and springs but i dont have $300,

Share this post


Link to post
Share on other sites
see i cant afford a new head, i was going to get rhc valves and springs but i dont have $300,

well then you can just re-cut your seats and install new stock valves and springs if you want to,

but no you do not need to replace your seats because of a ss valve, ( although i have herd alot of shops replacing them with the bronze seats :ride: )

but you will have to run a heavier spring set up for the heavier SS valve which i do not like ,

you can get some good time on the stock stuff if you have to ,----i still do alot of stock stuff for people, ---if your guides are good or just get new guides from cv4 and install them and run stock valves you can get 50 hrs or more out of the thing if you keep your air filter clean ------way more than your ring seal will last :applause:

oh , i re read your post -----i see you already have valves , -----ok---then make sure your valve guides are good ( it would not hurt to replace them with the better ones from cv4 ---your 04 ones are loose i can just feel it in my bones :applause: )

and just re-cut the seats and correctly install the valves and springs and go for it, :thumbsup:

Share this post


Link to post
Share on other sites

i heard that you need to replace the seats for SS valves or they will destroy the seats within a couple of rides. :thumbsup:

Share this post


Link to post
Share on other sites
i heard that you need to replace the seats for SS valves or they will destroy the seats within a couple of rides. :thumbsup:

even tho i will not use the heavy ss valves or their springs, i have gotten lots of heads to repair with them in there for 50 or so hrs and have not had a seat problem yet ,

i like the same weighted steel ( not ss )or the ti ferrea valves and have also had no seat problems at all,

but i have had heads where the shop tried to replace the seats with the bronze beryllium and the seat came loose and made a mess and destroyed a motor,

for years in auto and aviation we have always used this same hardened seat with ss or steel valves and have not had alot of trouble with them at all,

i see more of a problem with the guides way to loose, ---even with a new head they are too loose in my opinion,

i am doing a 250 right now that the guy bought a brand new head and i just do not like how loose the dam stock guides are :applause::ride:

i guess i will get some better guides for it and put them in :applause:

Share this post


Link to post
Share on other sites

To add to Kelstr's posts,

SS valves need good HD springs. SS valves are soft and are the sacrificial component when used against the stock seats. The stock seats are very hard to hole their shape from poundings and the micro grit from offroad racing. Copper Beryl. or Silicon 'Bronze seats are a good cushion and help extend the SS valve life as well as Ti valve life. With these CRF motors the proper springs are more important than seat material. As mentioned the guides in the CRF are very very important.

Share this post


Link to post
Share on other sites

faction mx comes as a kit, ss valves and springs, retainers and whatnot, im going to give it a try, my heads getting recut tomarrow, and if i assemble it and have any problem, whats the worst that will happen? i started out at point A again.. and i end up getting a 06 head

Share this post


Link to post
Share on other sites
well then you can just re-cut your seats and install new stock valves and springs if you want to,

but no you do not need to replace your seats because of a ss valve, ( although i have herd alot of shops replacing them with the bronze seats :ride: )

but you will have to run a heavier spring set up for the heavier SS valve which i do not like ,

you can get some good time on the stock stuff if you have to ,----i still do alot of stock stuff for people, ---if your guides are good or just get new guides from cv4 and install them and run stock valves you can get 50 hrs or more out of the thing if you keep your air filter clean ------way more than your ring seal will last :applause:

oh , i re read your post -----i see you already have valves , -----ok---then make sure your valve guides are good ( it would not hurt to replace them with the better ones from cv4 ---your 04 ones are loose i can just feel it in my bones :applause: )

and just re-cut the seats and correctly install the valves and springs and go for it, :thumbsup:

You apparently haven't broken CV4 exhaust valves yet. Also haven't you noticed your shims start to show signs of wear when you combine CV4 valves and higher pressure springs. That's because CV4 doesn't make the effort to micro polish the valves after machining.

Share this post


Link to post
Share on other sites
so my buddy who works at factory connection got me faction mx ss valves with springs and retainers for $100, and i sent my head out to a guy in massachusets "harry's machine parts" he does honda head work, and he told me my ss valves wont work with stock seats, and i need to get my seats removed and have bronze ones put in

is this true?, or can i just get away with my 04 valve seats recut :thumbsup:

thanks dp

You should be fine getting your seats recut for steel valves. Your exhaust valves are steel, and there is relatively minimal wear and tear on the seats with the stock valves, although I've seen some pretty bad exhaust valve seats due to negligence. The spring rate on the exhaust side should be fine for your replacement valves, although you should get HD springs on the intake side if you're going to run steel valves, and especially if you're running a more agressive cam profile. I feel bronze seats are to soft for steel valves, it's $65/pr for replacement steel valves but 4 times that to get your seats replaced. Better to toss the steel valves. Heck a new 06 head is only $250, so just go with a new head if need be. The best material for Ti valves is copper beryllium, but most places won't touch the stuff 'cause it's very toxic. The faction valves are a 21-4N steel alloy, good stuff for the money, if you decide to go with steel. You can check out the following link and decide for yourself.

http://www.automotiverebuilder.com/ar/eb050538.htm

Share this post


Link to post
Share on other sites

the engine is stock, cam is stock, the only performace is coming from my jetting, and cleaned up the ports a little bit, im not even running my pipe anymore

so im just going with the faction valves i have, and getting my seats cleaned up tomarrow for them, the worst thing that will happen is ill be out $100 for the valves if they dont work, and at that imm just get an 06 head, ill just miss a few races

Share this post


Link to post
Share on other sites

Kelstr, you like cv4 guides because they're a little tighter on the valve stem, I checked there site, I don't see that they make them, but they offer ones from Xceldyne, are they the ones you have had good experience with?

:thumbsup:

Share this post


Link to post
Share on other sites
the engine is stock, cam is stock, the only performace is coming from my jetting, and cleaned up the ports a little bit, im not even running my pipe anymore

so im just going with the faction valves i have, and getting my seats cleaned up tomarrow for them, the worst thing that will happen is ill be out $100 for the valves if they dont work, and at that imm just get an 06 head, ill just miss a few races

Make sure you change the springs. not sure if I read that you had them.

Share this post


Link to post
Share on other sites
Kelstr, you like cv4 guides because they're a little tighter on the valve stem, I checked there site, I don't see that they make them, but they offer ones from Xceldyne, are they the ones you have had good experience with?

Basically CV4 is the sales/marketing/warehouse facility. Xceldyne is the manufacturing facility. So yes, that would be the guides he is talking about.

The stock seats in the CRF's are extremely hard which tends to cause extra wear on Ti valves. The other problem with the stock seats is that they do not transfer heat very well. Beryllium copper and Ampco45 material is much softer and will disipate heat up to 7 times faster than the stock seat material. This is especially important when using Ti valves on the exhaust side in order to remove heat from the valves.

Proper machine work is the other key to the puzzle. Valve to seat concentricity is extremely important and even the slightest misalignment will cause excessive wear. As said earlier, correct clearances between the valve and guide is also important as loose guides will cause more wear on the valves and seats.

These engines are very similar to an Indy car engine. Quality parts, proper machine work, and a good maintenance schedule are absolutely necessary in order to expect longevity.

Share this post


Link to post
Share on other sites
You apparently haven't broken CV4 exhaust valves yet. Also haven't you noticed your shims start to show signs of wear when you combine CV4 valves and higher pressure springs. That's because CV4 doesn't make the effort to micro polish the valves after machining.

i was just talking the cv4 Guides ---not valves,

i just really like how nice and tight the cv4 guides are compared to the stock ,

if you really look and measure the stock clearance of the honda crf 250 guide --and or the 450's---it is sad ----they are really loose for as small of a valve and stem that they are holding ---.

this is a big wear problem -----if you look at the 250 bikes that go 120 hrs on their valves ( now i am talking stock kids at the track with a Hobbs meter )

vs the guys that can't go 20 hrs -----you will see one with kinda ok guides---and the 20 hrs ones are way loose :applause: ,

thats why with an 04 head with time on it ,----i was telling him to get the cv4 guides and he will be way better off !!

then since he has the valves and spring kit ( even tho they are not what i like ----so what ---he got them for $100.0 and they will work good for him !) :thumbsup:

and i will say that cv4 is back in the heart land of real racing and they do all the nascar and cup guys stuff,

they make all their stuff in house and the have engineers on sight that will make you anything anyway you want it , ---from guides , ti valves , seats --and psi spring kits ----,

now i have not used their in house ti valves ----but their guides are a very nice piece and their seats fit great if a guy needed them ,

its just so nice to have these big racing company's make stuff for us ,

you should have seen how long it would take me to make tighter guides on my own --- :applause::applause: ,

i would spend way to much time -----i got it done ----but at what real cost,

its just so nice to call on the phone and have them sent out ready to press in and go !! :ride:

Share this post


Link to post
Share on other sites

cv4 i have a question for you. yu said that for Ti valves, ampco45 and beryllium is a better seat material. on yuor site, i see the ampco seats for the exhaust. what is the intake one? is it CRF250R Valve Seat, Intake, 1.040" I.D. ? also, what does the -1 mean after the I.D.? i am putting in Ti valves again this fall and have the stock seats in there. i want to do this the right way :thumbsup:

Share this post


Link to post
Share on other sites

SMF919, all of the bike valve seats are Ampco45. The -1 indicates that that particular seat is .010" bigger on the O.D. than stock. We make the seats in a stock replacement size and an oversize so the guy doing the machine work can be sure to get the proper press fit. We shoot for a .004" to .005" press fit to make sure the seat doesn't come out.

Our website can be really confusing to say the least. :thumbsup: We're in the process of a complete overhaul but it will probably be 2 months at best before it's complete. Feel free to give me a call anytime and I will do my best to answer any questions you have. Ask for Shane.

Share this post


Link to post
Share on other sites

Hey every one my head is shot, and sh :thumbsup: it

i got it back from the shop and tehy said they dont have the right size valve bit, and while i was waiting for him to get me a place that will do it, i was playing around with it and i saw that my ex. valve seats are toast, and my new intake valves fit loosely in my intake guides also, so it ends up that i am getting an 06 head.. but where can i get them within the next 2 weeks?

since my head will be brand new, what valves do you recomend, my bike isnt under complete abuse so i dont need $43049093024909 valves, can i just use the factions mx ss ones i have that came with springs and whatnot? and what ex. valve should i use.. 60% of my riding is trail riding so its not getting beat constently.. kelstr what do you recomend i do?

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Reply with:

Sign in to follow this  

×