+1mm oversized valves any good?
Jan 25, 2010, 01:41 PM
#16
Former Sponsor
iTrader: (56)
Join Date: Sep 2004
Location: DFW, TX
Posts: 2,701
Likes: 0
Received 0 Likes
on
0 Posts
the X head has 35mm intake and 29mm exhaust valves (we've measured).
the intake side of the X is the same as a cosworth head (or a +1mm oversized valve).
although the exhaust valves on the X are smaller then even the stock valves on the 8/9.
the 8/9 head can both pick up great gains in flow by a simple port with stock valves. the X head flows far better then the 8/9 head completely stock (and in fact, a stock X head flows better then the big valve cosworth head on the intake side).
i've tested buschur ported 8 and 9 heads, both flow the same, and both flow a lot better then the stock, but are only using +.5mm bigger valves intake and exhaust (as such don't flow as much as the cosworth).
keep in mind though that as many people have mentioned, not everyone ports the heads for max CFM. i know buschur knows how well all these heads flow and he picked his for a reason.
(oh and i have the flow data for all these heads but i'm not giving it away because it was expensive to test them all).
the intake side of the X is the same as a cosworth head (or a +1mm oversized valve).
although the exhaust valves on the X are smaller then even the stock valves on the 8/9.
the 8/9 head can both pick up great gains in flow by a simple port with stock valves. the X head flows far better then the 8/9 head completely stock (and in fact, a stock X head flows better then the big valve cosworth head on the intake side).
i've tested buschur ported 8 and 9 heads, both flow the same, and both flow a lot better then the stock, but are only using +.5mm bigger valves intake and exhaust (as such don't flow as much as the cosworth).
keep in mind though that as many people have mentioned, not everyone ports the heads for max CFM. i know buschur knows how well all these heads flow and he picked his for a reason.
(oh and i have the flow data for all these heads but i'm not giving it away because it was expensive to test them all).
Last edited by KevinD; Jan 25, 2010 at 01:43 PM.
Jan 25, 2010, 02:04 PM
#17
the X head has 35mm intake and 29mm exhaust valves (we've measured).
the intake side of the X is the same as a cosworth head (or a +1mm oversized valve).
although the exhaust valves on the X are smaller then even the stock valves on the 8/9.
the 8/9 head can both pick up great gains in flow by a simple port with stock valves. the X head flows far better then the 8/9 head completely stock (and in fact, a stock X head flows better then the big valve cosworth head on the intake side).
i've tested buschur ported 8 and 9 heads, both flow the same, and both flow a lot better then the stock, but are only using +.5mm bigger valves intake and exhaust (as such don't flow as much as the cosworth).
keep in mind though that as many people have mentioned, not everyone ports the heads for max CFM. i know buschur knows how well all these heads flow and he picked his for a reason.
(oh and i have the flow data for all these heads but i'm not giving it away because it was expensive to test them all).
the intake side of the X is the same as a cosworth head (or a +1mm oversized valve).
although the exhaust valves on the X are smaller then even the stock valves on the 8/9.
the 8/9 head can both pick up great gains in flow by a simple port with stock valves. the X head flows far better then the 8/9 head completely stock (and in fact, a stock X head flows better then the big valve cosworth head on the intake side).
i've tested buschur ported 8 and 9 heads, both flow the same, and both flow a lot better then the stock, but are only using +.5mm bigger valves intake and exhaust (as such don't flow as much as the cosworth).
keep in mind though that as many people have mentioned, not everyone ports the heads for max CFM. i know buschur knows how well all these heads flow and he picked his for a reason.
(oh and i have the flow data for all these heads but i'm not giving it away because it was expensive to test them all).
Mar 8, 2010, 09:55 PM
#18
Newbie
iTrader: (15)
Join Date: Nov 2007
Location: Enfield , CT
Posts: 95
Likes: 0
Received 0 Likes
on
0 Posts
Okay i recently had a 1st gen head build for my 6 bolt build I am doing in my 2nd gen talon.. I I had my machine job do a bunch of blow bench testing on a number of heads
Bone stock 1st gen head
Bone stock 1st gen w/1mm os valves
P/P 1st gen head stock valves
p/p 1st gen head with 1mm os valves
I dont got all the data on me but will post legit cfm numbers and at what lift once I get the heads back with the data. They are doing some extrude honed vs sheet metal intake setups with thoses heads along with different throttle body combos.
Okay 1st gen head flows about 270cfm bone stock at .400 lift
Now to run 1mm os valves you have to extract the stock seats and put new ones in which the seats are cheap , but the labor cost might not be worth it unless ur building a race car.
1st gen head , no porting just 1mm os valves. only pulled up 264cfm@.400 lift . Engine builder said cause of the bigger seats and no blending the ports into the seats just caused turbelence and killing air flow.
1st gen ported 289cfm @.400 lift
1st gen ported with 1mm os valves 309 cfm @.400 lift
As u can see big difference with the 1mm os valves , but u have to some serious work and serious money into the head. and He tested my head up to .500 lift and the numbers well only got better , but I am doing 1st gen p/p with 1mm os valves cause i am building a weekend warrior , not a a daily. I am running 280s with 11.5 lift.
But to be clear on 1mm os valves they are good for fully build motors , not daily drivers. Also your machine shop needs to know what they are doing. If u dont blend the head right mainly around the new over sized seats and make everything flow correct then guess what u just waisted ur money on os valves. Plus its not all about cfm , its about velocity. Also u need a nasty sheet metal intake and 75mm or bigger TB to bring in the air to needed to take advantage of 1mm os valves.
So in the end I gained roughly 40cfm of air throw each port. thats 160cfm more air throw the entire motor. ur looking at big gains.
I also will have dyno numbers up in the next month 1st gen ported vs 1st gen port os valves.
My motor is
wiseco HD 9.0:1.. 20 over
manely rods
acl race rod and main bearings
arp head and mains
balance and blue printed
b/s elimantor
1mm os ss valves
gsc behivee springs
gsc chromoly spring seats
gsc titanium retainers
ferra locks
ferra guides
ferra seals
and a hole lot of porting and polishing
Bone stock 1st gen head
Bone stock 1st gen w/1mm os valves
P/P 1st gen head stock valves
p/p 1st gen head with 1mm os valves
I dont got all the data on me but will post legit cfm numbers and at what lift once I get the heads back with the data. They are doing some extrude honed vs sheet metal intake setups with thoses heads along with different throttle body combos.
Okay 1st gen head flows about 270cfm bone stock at .400 lift
Now to run 1mm os valves you have to extract the stock seats and put new ones in which the seats are cheap , but the labor cost might not be worth it unless ur building a race car.
1st gen head , no porting just 1mm os valves. only pulled up 264cfm@.400 lift . Engine builder said cause of the bigger seats and no blending the ports into the seats just caused turbelence and killing air flow.
1st gen ported 289cfm @.400 lift
1st gen ported with 1mm os valves 309 cfm @.400 lift
As u can see big difference with the 1mm os valves , but u have to some serious work and serious money into the head. and He tested my head up to .500 lift and the numbers well only got better , but I am doing 1st gen p/p with 1mm os valves cause i am building a weekend warrior , not a a daily. I am running 280s with 11.5 lift.
But to be clear on 1mm os valves they are good for fully build motors , not daily drivers. Also your machine shop needs to know what they are doing. If u dont blend the head right mainly around the new over sized seats and make everything flow correct then guess what u just waisted ur money on os valves. Plus its not all about cfm , its about velocity. Also u need a nasty sheet metal intake and 75mm or bigger TB to bring in the air to needed to take advantage of 1mm os valves.
So in the end I gained roughly 40cfm of air throw each port. thats 160cfm more air throw the entire motor. ur looking at big gains.
I also will have dyno numbers up in the next month 1st gen ported vs 1st gen port os valves.
My motor is
wiseco HD 9.0:1.. 20 over
manely rods
acl race rod and main bearings
arp head and mains
balance and blue printed
b/s elimantor
1mm os ss valves
gsc behivee springs
gsc chromoly spring seats
gsc titanium retainers
ferra locks
ferra guides
ferra seals
and a hole lot of porting and polishing
Thread
Thread Starter
Forum
Replies
Last Post
[WTB] Aftermarket +1mm valves
benIX
For Sale/WTB - Engine / Drivetrain / Power
1
Oct 21, 2016 11:23 AM
FreakEVO
Evo Engine / Turbo / Drivetrain
4
Aug 5, 2016 10:21 AM
wheredafucrwe
Evo Engine / Turbo / Drivetrain
2
Oct 26, 2004 12:10 AM
