4 stroke titanium valves with copper beryllium seats

[Braapdaddy]

Hello fellow BITOG friends are there any motocross engine guys on here or anyone who can share some info on a build I am doing for my sons race bike .......

The quick info and if anyone can relate or chime in I would be most thankful and then I can go into much greater detail if need be

2013 CRF250R had bike since new I rode it about 15 hours following my son around when he was on 50s and a little when he was on 85s

Now that he has moved up to 250s and a pretty solid rider with consistent improvement and the suspension valved and sprung we are looking to gain some HP to keep up with the kids who have brand new bikes and dads with deep pockets

With 140 hours total we have adjusted the valves one time and on the last tear down the feeler Guage tolerances were not in spec and took far too thin a Guage to slip in so I took it apart

Del West titanium valves exhaust and intake about $600
Hot Cams stage 2 $300 ish

Took it to a trusted shop who of course has to have the head sent to Cali for the machine work by " one of the best in the country "

We discussed my concerns and what I felt I wanted and the price was really not too concerning within rational reason

My ask list

My titanium valves with copper beryllium seats and the proper angles cut in the new seats

My stage 2 Hot Cams to be considered in the equation

Port/polish clean up (Quoted aprox $400) ....if it's legit no problem I say

.......3 months later after my guy keeps getting the run around about my head ( death in the family ) ......( running behind ) ....... ( broke down equipment) ........ ( Lorettas is coming up I have important builds that MUST BE DONE).....basicall stall and excuse bankrupt I finally am going to pick my head up Friday supposedly

My guy proceeded to tell me now the shop just ground my existing factory Honda valve seats because they said I didn't need them replaced ????....... mind you this has 15 hours cream puff and about 125 hours consisting 20 good local hard motos on it including practice sessions

Then said that my Hot Cams stage 2 would be a downgrade to the factory cam and that only a PC cam ( pro circuit) is worth putting in these bikes ??????....... I have to call B.S. on that one as well

I guess I will see what I get on Friday I'm expecting a let down

Aren't copper beryllium pretty much a must for titanium valves or is this not correct ??

I can't believe that that many hours and the old seats and guides aren't toast am I wrong ??

I am putting my stage 2 cam in and checking clearances anyways after all its my bike how can his clain this is a step backwards overall am I wrong ??

Guess I will see what I get when I pick it up
If I'm not satisfied who do you guys use for real head work on motocross race bikes

Thanks friends

 

[Cujet]

I'm not an expert on your bike and situation. However, despite today's claims to the contrary, many racers strongly believe leaded fuels do help valves last longer on their high RPM race engines. And there is not much question that in the racing world, the move from leaded racing fuels did drive the need for better valves seats. Ti can withstand a lot of heat, and Ti valves are often much lighter, resulting in higher RPM ranges. But heat transfer remains a problem, as does valve and seat lifespan.

Whether exotic hard copper valve seats help your Ti valves last significantly longer, or are the secret ingredient to avoiding early engine teardowns is probably known to only a few in the industry. Steel seats can work fine with Ti valves, if they remain in good shape. Which means, not pounded into submission and not corroded, overheated or flat out worn out.

Wish I could be of more help, but my secret to making those little engines hold up longer is a big bore kit, lowering the RPM range a touch.

 

[Braapdaddy]

I'm not an expert on your bike and situation. However, despite today's claims to the contrary, many racers strongly believe leaded fuels do help valves last longer on their high RPM race engines. And there is not much question that in the racing world, the move from leaded racing fuels did drive the need for better valves seats. Ti can withstand a lot of heat, and Ti valves are often much lighter, resulting in higher RPM ranges. But heat transfer remains a problem, as does valve and seat lifespan.

Whether exotic hard copper valve seats help your Ti valves last significantly longer, or are the secret ingredient to avoiding early engine teardowns is probably known to only a few in the industry. Steel seats can work fine with Ti valves, if they remain in good shape. Which means, not pounded into submission and not corroded, overheated or flat out worn out.

Wish I could be of more help, but my secret to making those little engines hold up longer is a big bore kit, lowering the RPM range a touch.

I do have a JE piston higher compression on the bench just waiting to get this head back .....

I guess my other gripe is more a customer service issue
When I ask for porting and my cam to be considered and am literally told to accept the exact opposite I feel I have been had .....

Thank you for your input

 

[853okg]

I also have nothing definitive to add, but I agree you weren’t the recipient of stellar customer service. I’d try to develop a relationship with someone local if possible. I have noticed that good service has become incredibly hard to find lately. It’s as if nobody wants to work anymore.

 

[Braapdaddy]

I also have nothing definitive to add, but I agree you weren’t the recipient of stellar customer service. I’d try to develop a relationship with someone local if possible. I have noticed that good service has become incredibly hard to find lately. It’s as if nobody wants to work anymore.

True

 

[Cujet]

I guess my other gripe is more a customer service issue
When I ask for porting and my cam to be considered and am literally told to accept the exact opposite I feel I have been had .....

You are probably not wrong. I had a small business doing 2 stroke porting on specific race engines. I had only one difficult and troublesome customer who did not package his engine well and it was damaged in shipping to me. I never charged him, for the repairs or porting, and we parted ways. Even the troublesome guy called back to report the speed increase. The rest were pleased as can be, with the huge HP and speed increase.

But I knew exactly what I was providing, stated exactly what they were getting with regard to port specifications in both MM of change and crankshaft degrees. (none of this Mild, medium or spicy), and understated the HP increase, as most people were going to run the wrong pipe or carb setups anyway.

It is a shame that the racing industry remains full of difficult people, providing services of limited benefit.

 

[Braapdaddy]

You are probably not wrong. I had a small business doing 2 stroke porting on specific race engines. I had only one difficult and troublesome customer who did not package his engine well and it was damaged in shipping to me. I never charged him, for the repairs or porting, and we parted ways. Even the troublesome guy called back to report the speed increase. The rest were pleased as can be, with the huge HP and speed increase.

But I knew exactly what I was providing, stated exactly what they were getting with regard to port specifications in both MM of change and crankshaft degrees. (none of this Mild, medium or spicy), and understated the HP increase, as most people were going to run the wrong pipe or carb setups anyway.

It is a shame that the racing industry remains full of difficult people, providing services of limited benefit.

You have eased my mind on the guide and seat material not necessarily having to be copper beryllium or something unique

As far as the racing industry goes my race shop I am using is still in the industry at the highest level each weekend and has built some bikes for some really successful riders all the way back to the 90s camel supercross up to bikes that just competed at Lorettas

I think my money was no good or not as important we are never going to be Jett or Hunter or danger boy and our bike isnt a 2022+ but we sure as hell are enjoying our time in the sport and there are lots of fun to be had

 

[Cujet]

You have eased my mind on the guide and seat material not necessarily having to be copper beryllium or something unique

I'm glad you are more comfortable. Clearly, those ultra high RPM 4strokes are tough on heads. Many simply purchased replacement heads to swap out, when the time came.

I guess to my point above, these parts have a fatigue life, in addition to a wear lifespan. They are quite literally beaten into submission.

Post a few pics of the parts, as you assemble them. Many of here find that quite interesting.

Here is what I spent yesterday playing with:

 

[Braapdaddy]

I'm glad you are more comfortable. Clearly, those ultra high RPM 4strokes are tough on heads. Many simply purchased replacement heads to swap out, when the time came.

I guess to my point above, these parts have a fatigue life, in addition to a wear lifespan. They are quite literally beaten into submission.

Post a few pics of the parts, as you assemble them. Many of here find that quite interesting.

Here is what I spent yesterday playing with:

Nice big boy toys my friend ......do you use Phillips or Shell ? What part of the country you fly over ?

I do have a complete spare head and quite a few extras I have complied up for this bike for just in case as well as another complete engine that cracked the side case on the chain side due to a chain derail still ran before we pulled it ..... traded parts for it so nearly zero investment I plan on building this one as the stroker or big bore when my boys skills rise to the need

 

[Cujet]

Aeroshell 15W-50 in the little toys.
Mobil 254 in the EC-135 helicopter
Eastman 2380 (the old Esso/Exxon/BP) in the Pilatus PC-12 and G600
Mobil 1, 10W-40 4t racing oil in the Stemme S10 motorglider.

 

[ragtoplvr]

Since Beryllium is toxic, my experiences with OSHA so far would scare me off. Hasmat disposal off the chips.

 

[oil pan 4]

I don't know of big engines with titanium valves using beryllium valve seats or any other beryllium parts.

 

[BigMoneyGrip]

That guy is probably right about the stock cam. The mfg's have these engines running on the ragged edge. Aftermarket cams might increase peak power some, but it will take it from another area.
The key to the Ti valves is to keep the air filter clean. I like to put a fresh one on after each moto. Once the coating is eroded from the valve, you need to replace the valve. Once you have to adjust the valves because the clearances keep getting out of spec, it's time to replace them.

 

[97prizm]

I'm glad you are more comfortable. Clearly, those ultra high RPM 4strokes are tough on heads. Many simply purchased replacement heads to swap out, when the time came.

I guess to my point above, these parts have a fatigue life, in addition to a wear lifespan. They are quite literally beaten into submission.

Post a few pics of the parts, as you assemble them. Many of here find that quite interesting.

Here is what I spent yesterday playing with:

Extra 300s? It's not a zlin or Yak. Very nice.

 

[Cujet]

Extra 300s? It's not a zlin or Yak. Very nice.

Extra NG. The latest Extra. Pretty amazing machine. Not as "hard core" as the latest crop of aerobatic planes such as the "GB1 Game Bird". Even so, it's no slouch or second rate machine. It is still a +/- 10G, IO580 powered, all carbon, lightweight monster. It gives a nod to being useful, with a 190Kt cruise speed. Does it all, does it very, very well.

 

[Cujet]

Although the aircraft engines are low volumetric efficiency, about 70% at peak HP, they do suffer from the similar valve issues the OP is dealing with. The valves are very large, the cylinder heads run hot (about 400° F) and valve to head/valve guide heat transfer is a real problem. Leading to premature valve, seat and valve guide failures.

Many are unaware that even with lowly aircraft piston engines, material science of these parts has changed. Bronze valve guides have been replaced with high nickel guides, the steel valves have been replaced with sodium cooled valves, and valve seat material has been upgraded.

 

[97prizm]

Extra NG. The latest Extra. Pretty amazing machine. Not as "hard core" as the latest crop of aerobatic planes such as the "GB1 Game Bird". Even so, it's no slouch or second rate machine. It is still a +/- 10G, IO580 powered, all carbon, lightweight monster. It gives a nod to being useful, with a 190Kt cruise speed. Does it all, does it very, very well.

How does it fly compared to the edge 540? Or for grins the Pitts macho stinker which is the 900 hp radial and can hover vertically. When did it become Textron-Lycoming?

 

[Cujet]

How does it fly compared to the edge 540? Or for grins the Pitts macho stinker which is the 900 hp radial and can hover vertically. When did it become Textron-Lycoming?

Many of those other planes will out perform even the latest Extra. I’ve not flown an Edge 540, I have flown a MX2 with w/modified parallel valve IO540 290HP. The MX2 clearly has better powa to weight and will probably outperform the Extra in every category.

 

[sunruh]

that era of crf250r motors is notorious for eating valves. i mean like tic tacs. nom nom nom.
i had a racing buddy that went through 4 sets of valves and 2 heads in just 1 season and just hated the entire experience.
loved how the bike rode...hated the amount of work he put into the head/valves.
there is no amount of parts that will fix that head. thats why honda kept changing it and changing it and changing.
potentially the only head worse was the 04 kawasuki that ate valves almost as fast which another buddy had back then.

your cheapest solution...truly...is a 2022 bike (if you consider your own time worth more than a wooden nickel)

 

[Braapdaddy]

that era of crf250r motors is notorious for eating valves. i mean like tic tacs. nom nom nom.
i had a racing buddy that went through 4 sets of valves and 2 heads in just 1 season and just hated the entire experience.
loved how the bike rode...hated the amount of work he put into the head/valves.
there is no amount of parts that will fix that head. thats why honda kept changing it and changing it and changing.
potentially the only head worse was the 04 kawasuki that ate valves almost as fast which another buddy had back then.

your cheapest solution...truly...is a 2022 bike (if you consider your own time worth more than a wooden nickel)

Thank you for the reply I have put far to many things into this 250 to change at this moment I do predict a new bike if everything turns out like I plan for the 2025 MY

Been busy with the extreme heat but I am picking the head up tomorrow then I can see what I did and did not get for my money