valve interchangability?

Jugador

New Member
Aug 30, 2003
70
0
0
are turbo head valves stainless (or at least better than dual plug valves)? i'm basically looking to foolproof my dual plug engine as much as possible so i can increase the boost and make mo powah without breaking much. i'd like to do it as cheap as possible (esslinger=out of the question unless absolutely necessary). if turbo head valves are interchangable with dual plug valves i could swap them and be able to handle more boost right?


thanks
 
  • Sponsors (?)


no / yes with stipulations
Only turbo exhaust valves are different. They are filled with a material that escapes my mind right now. It isn't sodium, but it acts as a heat pipe at operating temperature.
You can swap them over, but you will need to get a valve job to ensure you get sealing.
The dual plug motor isn't a great starting point. It has high compression, small fuel injectors, and way to much timing advance.
why not come up with a turbo engine? I promise it would be just as cheap, and cheaper in the long run when you blow the dual plug motor.
 
when i blow the dual plug, a 5.0 will find its way in, and then it will find a holset turbo next to it. that's no issue. i just want to make this one fun and somewhat reliable while it lasts. i can get bigger injectors (i think it has 36#'s tho), i have forged low comp pistons, im gonna get an adjustable cam gear and adjustable fuel pressure regulator. i just want to know what's the deal with valves, that's all. i know this thing's a timebomb.

exhaust valves will be the ones that run the most risk of burning, so that does me little good doesn't it? do valve jobs cost a lot? is there any way around that, be it adjusting something myself, using something off the dual plug valvetrain, etc etc?
 
Yes the the Turbo exhuast valves are differnt, change them out. locally i get a valve job 60-80$....no real way of getting around it since these valves seats are use to a completely differnt valve. If ya cut this corner, you might aswell wait for the 5.0 swap IMO.
 
oh i was thinking this was gonna be a couple hundred dollar job, thats doable for peace of mind. now my next question is how long will these valves last? they'll be able to withstand say 15-20 psi right?
 
Jugador said:
oh i was thinking this was gonna be a couple hundred dollar job, thats doable for peace of mind. now my next question is how long will these valves last? they'll be able to withstand say 15-20 psi right?


Yes and no. Valves are your usualy your last problem at higher boost levels. Many guys run 20+psi all day long with no trouble. 15 psi, easy...that is "stock" boost levels. Basicly running 20psi of boost rely's on fuel, timing,ignition and compression level...if you have a compression ratio in the 8's, you should be fine.
 
Jugador said:
oh i was thinking this was gonna be a couple hundred dollar job, thats doable for peace of mind. now my next question is how long will these valves last? they'll be able to withstand say 15-20 psi right?
the stock valves could do that for a while. If you can avoid detonation, the pistons/rings will survive... but anything can happen. I put a turbo on my 88 2.3 NA mustang, and it lasted for a while... until the vacume reference blew off the fuel pressure regulator. That caused fuel pressure to drop by 15psi, and broke a couple rings.
Anyway, unless you have some major octane in your gas, there is no way you will be running 20psi on 9.5:1 compression.
 
to quote myself 2 replies ago, "i have forged low comp pistons" (not sure what compression ratio that would put me at because i dont know if the head is what causes more compression on the dual plug motors). i am not worried about the bottom end withstanding boost. i use 93 octane, have a front mount, and if necessary i will get a cam gear so i can mess with timing. i just want more boost. valves were the next problem i saw. if my na valves can withstand 15-20 psi then i won't bother, but if they can't, i'll probably get the head done up at a machine shop.
 
is the head off right now? if so, you'd be money(backbreaking labor) ahead to do it now. Every setup is a little differnt, unless you have tunning available to you (dyno or wideband) ...like i said 15 is attainable, 20 is pushing your luck.
 
i have another dual plug head available that i would buy the valves for and put them on before i put the head on. i'd probably get a good gasket too since the head's off (just to eliminate any possible future problems). someone on turboford is selling stainless big valves, i might just buy those and have them put on...that way i'll get some top end power off it too. after a good hg and stainless valves, what other problems would i really be facing?
 
If you're taking the head off you really should try and find a pre 91 head to replace it with, but KEEP the roller cam and lifters...

The single angle valve job is horrendous, you don't know how much power is being held back by those pos factory seats. Yes a 3 angle valve job is only $80. 5 angle is better but probably not enough improvement in this case to justify the extra expense. (Cutting around the seat improves airflow thru the valve) Not to mention your stock valves and seats get burned out over time, you will reclaim lost power by renewing the cylinder seal.

Also the older heads will lower your compression allowing for more boost, unless I'm mistaken and the pistons are differnt?
 
JamesBaumann said:
I'm pretty sure the 87-90 n/a 2.3's and the 91-93 DP n/a 2.3's had the same pistons. However, don't take that to the bank, but I'm pretty sure they are the same.


I believe the 91-93 2.3's dualplug had created a tidbit higher compression, which with the roller cam/DIS and maf helped push it to the 105hp ...wheres a n/a exspert when u need'em!