diabolical1
09-10-2014, 04:58 PM
I'm not sure if I'll get answers here or not, but I posted this in the B5 S4/RS4 forum without thinking it might have been better to post it in a Tech forum. [:(]
I've finally started working on my heads and I've got a few questions for any of you that will share. For now, most of it is exhaust side because that's where I am, but I'll use this thread to ask whatever questions come up along the way.
1. With the combustion chambers turned up and the exhaust side away from you, there is a port next to the valve guides in the LEFT ports only. I'm curious what those ports are for.
2. I've seen some people do heads where they shave the valve guides flush with the port bowl and others where the guide are left alone. I doubt if any testing has been done, so I'll ask for opinions here. I can guess what the presumed benefit is, but what are the drawbacks of shaving the guide flush?
3. Has anyone ever tried to alter the combustion chamber on one of these heads to de-shroud the valves - particularly the exhaust valves?
4. In this thread: http://www.audizine.com/forum/showthread.php/467275-Anyone-use-these-exhaust-valves-before?p=7207879&viewfull=1#post7207879 - the final post talks about Inconel being brittle. In his defense, he also said that he was drumming up a worst-case-scenario, so I get that. I also understand that a broken valve - ANY broken valve - is shrapnel and can cause collateral damage. However, until now I had pretty much decided to go with Inconel. I just want to hear thoughts on using stainless versus Inconel.
5. Retainers ... I just wanted to know what upgrade options are out there beside Titanium. Has anyone here used OEM retainers with upgraded springs with good, LONG-TERM results? I am leaning toward going with upgraded springs (I'd say 75/25 right now), but I get mixed advice on Titanium in long-term use. I just want to know what options are available and OEM can remain an option for these engines.
Thanks for any information, advice or references.
Non-Technical question - Considering all my exhaust valves were FUBAR'd, does anyone have any straight ones laying around gathering dust? If I can get 6 that would be great, but I can make 2 work just as easily. I basically need some to do the combustion chamber work when I get to it.
I've finally started working on my heads and I've got a few questions for any of you that will share. For now, most of it is exhaust side because that's where I am, but I'll use this thread to ask whatever questions come up along the way.
1. With the combustion chambers turned up and the exhaust side away from you, there is a port next to the valve guides in the LEFT ports only. I'm curious what those ports are for.
2. I've seen some people do heads where they shave the valve guides flush with the port bowl and others where the guide are left alone. I doubt if any testing has been done, so I'll ask for opinions here. I can guess what the presumed benefit is, but what are the drawbacks of shaving the guide flush?
3. Has anyone ever tried to alter the combustion chamber on one of these heads to de-shroud the valves - particularly the exhaust valves?
4. In this thread: http://www.audizine.com/forum/showthread.php/467275-Anyone-use-these-exhaust-valves-before?p=7207879&viewfull=1#post7207879 - the final post talks about Inconel being brittle. In his defense, he also said that he was drumming up a worst-case-scenario, so I get that. I also understand that a broken valve - ANY broken valve - is shrapnel and can cause collateral damage. However, until now I had pretty much decided to go with Inconel. I just want to hear thoughts on using stainless versus Inconel.
5. Retainers ... I just wanted to know what upgrade options are out there beside Titanium. Has anyone here used OEM retainers with upgraded springs with good, LONG-TERM results? I am leaning toward going with upgraded springs (I'd say 75/25 right now), but I get mixed advice on Titanium in long-term use. I just want to know what options are available and OEM can remain an option for these engines.
Thanks for any information, advice or references.
Non-Technical question - Considering all my exhaust valves were FUBAR'd, does anyone have any straight ones laying around gathering dust? If I can get 6 that would be great, but I can make 2 work just as easily. I basically need some to do the combustion chamber work when I get to it.