Valve springs
- Thread starter NJ_LLY
- Start date
I understand how a lighter retainer would reduce the inertia and aid in valve spring return speed.
I have seen valve stems pull through retainers with upgraded springs.
I have not personally seen upgraded valve springs float with steel retainers. I do however agree that there is a rational logic behind the inertia.
I was confused why you would reduce spring pressure with light retainers, and I think it was just not the best example.
I would be upgrading retainers for strength as in my experience I have seen Fords pull them through retainers, never in a Duramax 6.6 though.
I have seen valve stems pull through retainers with upgraded springs.
I have not personally seen upgraded valve springs float with steel retainers. I do however agree that there is a rational logic behind the inertia.
I was confused why you would reduce spring pressure with light retainers, and I think it was just not the best example.
I would be upgrading retainers for strength as in my experience I have seen Fords pull them through retainers, never in a Duramax 6.6 though.
Doesn't matter. He still thinks he's right. Every builder I have ever talked to and everything I have read says they get changed for weight and strength if any is just a bonus but whatever.:beatdeadhorse:
Dale,
I understand the principle of the lighter weight and low inertia. It is great in a 16000 rpm road race motorcycle engine I used to build and race 15 years ago. In a 5500 rpm diesel I am not convinced the benefit is as great as the velocity of the valve tip is not that fast. Kenitic energy is a function of 1/2 mass times velocity squared. So the mass is no where near the factor as velocity in terms of inertia.
It is an added beneifit I agree.
I was offering advice based on experience i have seen first hand on diesel light duty engines that had the valve springs upgraded and used a stock retainer. The valve stem had pulled through the retainer and the valve dropped. This is a lot more destructive than a valve float and piston kiss. Upgrading the retainers and locks for strength is imho the most important reason to do it in a light duty diesel. We are typically doubling the seat pressure from 60 to 110 on these heads.
If you guys are doing it to lower inertia and valve float that is great. I run down the track at 5500 rpm all season long in my lly when I sled pull. I have steel retainers and I have never kissed a piston. I have a increased lift/duration cam and I do not have a relief cut in top of my piston.
I understand the principle of the lighter weight and low inertia. It is great in a 16000 rpm road race motorcycle engine I used to build and race 15 years ago. In a 5500 rpm diesel I am not convinced the benefit is as great as the velocity of the valve tip is not that fast. Kenitic energy is a function of 1/2 mass times velocity squared. So the mass is no where near the factor as velocity in terms of inertia.
It is an added beneifit I agree.
I was offering advice based on experience i have seen first hand on diesel light duty engines that had the valve springs upgraded and used a stock retainer. The valve stem had pulled through the retainer and the valve dropped. This is a lot more destructive than a valve float and piston kiss. Upgrading the retainers and locks for strength is imho the most important reason to do it in a light duty diesel. We are typically doubling the seat pressure from 60 to 110 on these heads.
If you guys are doing it to lower inertia and valve float that is great. I run down the track at 5500 rpm all season long in my lly when I sled pull. I have steel retainers and I have never kissed a piston. I have a increased lift/duration cam and I do not have a relief cut in top of my piston.
Justin, It's ok to admit that you were totally fukn wrong!!!
Here's a link so you can get up to speed.
http://www.sbintl.com/tech_library/articles/understanding_high_performance_valvetrain_technology.pdf
I should not have said that Zak. I upgrade them because I have seen them pull through. But I understand they are intended to reduce valvetrain mass.
I have my reservations about how important that is in our duramax but yes I should have said that is why upgrade and not that is the only reason why it is recommended.
I think I am entitiled to that opinion based on personal experience, and I also feel like I explained it fairly well in my subsequent replies.
I was WRONG to have said titanium retianers in my original response. I should have replaced the word titanium with upgraded I agree. It was a poorly edited post.
I apologize for not catching that earlier. However if you read my subsequent explanations I think I explained that thoroughly.