Just a warning for nitrous on 08 busa's

[kingofdacoast]

Just so everyone knows, I have a few friends who have had valve keepers come loose on their 08 busa's. This happens when killing the engine at higher RPM's with air shifters. GSXR's were notorious for them. If your going to spray nitrous stay out of the redline. Best thing to fix this is heavy duty valve springs. I haven't seen this myself yet on the 08 busa but they called and told me about theirs. Just FYI.

 

[dadofthree]

 

[ToXSicK RoCKeT]

Just so everyone knows, I have a few friends who have had valve keepers come loose on their 08 busa's. This happens when killing the engine at higher RPM's with air shifters. GSXR's were notorious for them. If your going to spray nitrous stay out of the redline. Best thing to fix this is heavy duty valve springs. I haven't seen this myself yet on the 08 busa but they called and told me about theirs. Just FYI.

OUTCH! Thanks for the heads up.

 

[Draco1340]

Yup, spring pressure should be bumped up to around 60 - 65 lbs, but unfortunatly the Ti valves won't take that amount of force, so you also need to upgrade to SS valves. And while your in there you should port head and put an exhaust cam in there. Unfortunatly thats a bit of scratch to go through the head.

 

[HillsRider]

Guess I am confused about the Ti valves not being able to take the heavier spring force. Are they a 2 piece valve?

 

[2Wheels2Live]

Yup, spring pressure should be bumped up to around 60 - 65 lbs, but unfortunatly the Ti valves won't take that amount of force, so you also need to upgrade to SS valves. And while your in there you should port head and put an exhaust cam in there. Unfortunatly thats a bit of scratch to go through the head.

Yep the 08's have some little tricks to reduce drag, lower spring pressure is one, ti valves are another
Unfortunately usually you give to get performance wise

 

[Mr Bogus]

you say 60-65 lbs on the valves... I am guessing you are talking on the SS valves.. the Ti valves should be proportionately lighter.. We ran Titanium valves in our car motors without much issue other than the outrageous costs.. the lighter valve used a lighter spring.. (this was only on naturally aspirated motors)

What happens on the these valves? come apart? cupping? stretching?

 

[ToXSicK RoCKeT]

you say 60-65 lbs on the valves... I am guessing you are talking on the SS valves.. the Ti valves should be proportionately lighter.. We ran Titanium valves in our car motors without much issue other than the outrageous costs.. the lighter valve used a lighter spring.. (this was only on naturally aspirated motors)

What happens on the these valves? come apart? cupping? stretching?

You are a 100% Correct biscuit. From what i've seen and read MOST engine builders are recommending the 45lbs springs for the 08's.

 

[Draco1340]

45 pounds on Ti valves might work. In general Ti has much less stiffness (modulus of elasticity) and much lower hardness and wear resistance than stainless, so the valves would wear much faster at high spring pressure, but 45# might work. I will still stick with the tried and true 1 mm oversize SS valves when I pull the head this winter. Bigger exhaust valves and a slightly bigger valve land have been a big help with spray motors I have had in the past. More thermal conduction path along the valve seat is key. If anyone has experience with building N2O motors with Ti valves, I am interested in learning.

 

[kingofdacoast]

I stay away from Ti valves on all my nitrous builds. SS is what I use.

 

[Mr Bogus]

Hmmm maybe I buy a set of the Ti takeouts... (springs/retainers too pls)

 

[ToXSicK RoCKeT]

I stay away from Ti valves on all my nitrous builds. SS is what I use.

Whys this drake? You have SS in your 08 grey/slvr(project bike)?

 

[ToXSicK RoCKeT]

45 pounds on Ti valves might work. In general Ti has much less stiffness (modulus of elasticity) and much lower hardness and wear resistance than stainless

Your saying ss is a harder metal then ti? ??? I dont understand your post here? I thought it was just the opposite.

 

[Draco1340]

Your saying ss is a harder metal then ti? ??? I dont understand your post here? I thought it was just the opposite.

Titanium actually has 1/3 the stiffness (modulus) and has MUCH less harness than hardened steel. You might be thinking of Ti coatings on tool steel cutters and knives and such. Hard coatings (gold or brown colored) are actually Titanium Aluma-Nitride, or Titanium Nitride. These are ceramic sputtered coating, and they are can be close to the hardness of diamond. Titanium metal on the other hand is not nearly as hard as steel. Titanium's basic utility is its strength to weight ratio; because its very light and has good tensile strength.

And yes, Now that I will be running a full time nitrous program next year, I will be putting in oversize SS valves this winter to replace the Ti. And a big exhaust exhaust cam to get the nitrous out.

 

[69chevydr]

Well I have been around drag cars for about 25 years and the amounts of nitrous going into a Pro-Modified car with its 800 cid engine is amazing ,and all these engines have titanium intake and exhaust valves. Some cars have up to 4 stages of nitrous proggressively building up to an additional 800 + hp just from nitrous.

 

[kingofdacoast]

Whys this drake? You have SS in your 08 grey/slvr(project bike)?

Not yet. Lee is still testing how much they are going to take. He likes to be gentle. I will spray the crap out of them untill they fail (remember my bucket of parts, LOL). He's doing my head now and I will be putting a SS set in mine for the amount of nitrous I'm planning on spraying in this one.

 

[ToXSicK RoCKeT]

Not yet. Lee is still testing how much they are going to take. He likes to be gentle. I will spray the crap out of them untill they fail (remember my bucket of parts, LOL). He's doing my head now and I will be putting a SS set in mine for the amount of nitrous I'm planning on spraying in this one.

Man, this has got me a little concerned, i ALWAYS thought "ti" was the best way to go.......Period! Wonder why ti rods are so good to use in race motors?
So drake, on your buddys 08.....it actually "dropped" the valve into the piston? Did the "keeper(s)" just pop off or it ripped the stem off the valve? Thx man

 

[ToXSicK RoCKeT]

Titanium actually has 1/3 the stiffness (modulus) and has MUCH less harness than hardened steel. You might be thinking of Ti coatings on tool steel cutters and knives and such. Hard coatings (gold or brown colored) are actually Titanium Aluma-Nitride, or Titanium Nitride. These are ceramic sputtered coating, and they are can be close to the hardness of diamond. Titanium metal on the other hand is not nearly as hard as steel. Titanium's basic utility is its strength to weight ratio; because its very light and has good tensile strength.

And yes, Now that I will be running a full time nitrous program next year, I will be putting in oversize SS valves this winter to replace the Ti. And a big exhaust exhaust cam to get the nitrous out.

Thank You, did not know that.......i was under the assumption ti was VERY strong.....learn something new everyday!

 

[kingofdacoast]

Man, this has got me a little concerned, i ALWAYS thought "ti" was the best way to go.......Period! Wonder why ti rods are so good to use in race motors?
So drake, on your buddys 08.....it actually "dropped" the valve into the piston? Did the "keeper(s)" just pop off or it ripped the stem off the valve? Thx man

The keepers just came loose. He got lucky and didn't drop the valve. Another friend of mine had the same thing happen to him and he got lucky. When I first heard my motor when it tore up I thought I had dropped a valve until I pulled my oil pan. I checked my head when I torn it apart and everything looked fine but I only have made 3 pass's on the 08 since I've owned it. I'll show you some pics of my Ti valves out of my 06 1k from shooting nitrous to them. I'll post them later.

 

[kingofdacoast]

Here are two of the Ti valves I had in my 06. This was after one pass on a 150 shot. Also a pic of the pistons. These pistons were custom made JE low compression (10:1) stock bore pistons.