|
| tickford_6 |
|
||
Posts: 6449 Joined: 11th Nov 2004 |
{USERNAME} wrote: Just by looking at the valve seat inserts there is enough meat there tap larger ones in, which I believe would require relieving the pistons as well for the extra large diameter intake valve.  can't do one without addressing the other I reckon. sorta like a domino effect process, it takes a lot of time to completely alter something that was restricted for emission purposes. you can machine the seat from a 39mm exhaust head to take the 41mm XR valve. you should be able to do the same with the intake seat. the problem right now is no one has the valve as an off the shelf item |
||
| Top | |
||
| gogetta |
|
|||
|
pretty sure you can use windsor or cleveland valves with a bit of mix and matching....plus stainless are available etc
_________________ |
|||
| Top | |
|||
| tickford_6 |
|
||
Posts: 6449 Joined: 11th Nov 2004 |
some usefull stuff.
       
|
||
| Top | |
||
| Slick |
|
|||
|
{USERNAME} wrote: pretty sure you can use windsor or cleveland valves with a bit of mix and matching....plus stainless are available etc The beauty of that is if the valves are equal in length but thinner or thicker stems is you can source valve guards inserts to match, including larger diameter valve seats. it's just a matter of finding the time to hunt them down.
_________________ Mind f**k!!! it works on feeble minded ignorant sheeples... there's plenty of em on this site... some are very intelligent but by god they are so thick!!! {USERNAME} wrote: You can buy them seppertly
|
|||
| Top | |
|||
| galapogos01 |
|
|||
Posts: 1139 Joined: 27th Feb 2005 Ride: Supercharged EF Fairmont Location: T.I. Performance HQ |
By that book, we should be looking at 2" or larger intake valves to suit the 4L?
_________________ {DESCRIPTION} - {DESCRIPTION}, {DESCRIPTION}, {DESCRIPTION}, {DESCRIPTION} and more! |
|||
| Top | |
|||
| KWIKXR |
|
|||
|
Nice scans there tickford_6.
{USERNAME} wrote: By that book, we should be looking at 2" or larger intake valves to suit the 4L? Pretty much, problem is trying to fit larger intake valves, there doesn't appear to be much room to go too oversize. Here's another link i found about exhaust valves which i reckon is pretty good. This site has a few other links of useful info.. {DESCRIPTION} |
|||
| Top | |
|||
| tickford_6 |
|
||
Posts: 6449 Joined: 11th Nov 2004 |
{USERNAME} wrote: By that book, we should be looking at 2" or larger intake valves to suit the 4L? I don't think there is enough space in the chamber to get a 2" (51mm) valve in there. We may squeeze in a 49 valve though. |
||
| Top | |
||
| KWIKXR |
|
|||
|
I know its not to do with porting but i just remembered i had a 94AB head a while back that i had sitting next to my 91AA one. Could of sworn the 2 heads looked exactly the same, same chamber design, had the guide bosses etc etc. Not sure if port sizing went unchanged but im guessing they could well be the same. One noticeable difference (only difference i saw apart from the casting numbers obviously) i saw was the oil galleries on the 91AA head are bigger than the 94AB.. Random i know, but just thought i'd share it since we are comparing different heads.. lol
91AA on the left..   
|
|||
| Top | |
|||
| xcabbi |
|
||
|
Looks like the area around the spark plug is clearly more built up on the 91AA.
Hey tickford 6 what's the part number of the AU VCT head? Also can you tell us the combustion chamber volume (pics please), intake and exhaust port volumes and cross sectional areas at the gasket faces as well as valve diameters? Hopefully we can get a head library happening. |
||
| Top | |
||
| tickford_6 |
|
||
Posts: 6449 Joined: 11th Nov 2004 |
{USERNAME} wrote: Looks like the area around the spark plug is clearly more built up on the 91AA. Hey tickford 6 what's the part number of the AU VCT head? Also can you tell us the combustion chamber volume (pics please), intake and exhaust port volumes and cross sectional areas at the gasket faces as well as valve diameters? Hopefully we can get a head library happening. can do. will try to get he bit to work and bead blast them, i also have the equipment there to 'cc' everything. i'll get the part number tomorrow |
||
| Top | |
||
| xcabbi |
|
||
|
No rush. I won't be able to make any progress myself until at least the end of the month.
|
||
| Top | |
||
| KWIKXR |
|
|||
|
{USERNAME} wrote: Looks like the area around the spark plug is clearly more built up on the 91AA I think the polished surface of the 91AA chamber and the lighting angles may have given it that effect, the 94AB does have the section where the spark plug protrudes into the chamber built up as well to a similar if not, the same extent. All the carbon build up on the 94AB is just hiding it real well 
|
|||
| Top | |
|||
| xcabbi |
|
||
|
I'll clean up my cracked 94Ab on the weekend and post some pics. The CMS stage 2 94AB appears to have untouched combustion chambers (casting surface still evident) and doesn't have that much shrouding around the spark plug.
|
||
| Top | |
||
| Slick |
|
|||
|
{USERNAME} wrote: I know its not to do with porting but i just remembered i had a 94AB head a while back that i had sitting next to my 91AA one. Could of sworn the 2 heads looked exactly the same, same chamber design, had the guide bosses etc etc. Not sure if port sizing went unchanged but im guessing they could well be the same. One noticeable difference (only difference i saw apart from the casting numbers obviously) i saw was the oil galleries on the 91AA head are bigger than the 94AB.. Random i know, but just thought i'd share it since we are comparing different heads.. lol 91AA on the left.. Hmmm, there's not much room there to shroud around the intake for bigger valves. the only way to find out how much room to play with is to measure the narrowest point between the chamber and piston bore. might have to line up a head gasket on the head with makeshift dowels, ink the the expose piston bore outline with a marker then lightly scribe the area to be shrouded. I have to agree with Tickford on the limitation on valve sizes here. blue is the piston bore diameter, red is the chamber out line and the lime colour is the narrowest point around the intake valve.  Another thing that'll be handy is collecting information on all the i6's and how they all line in comparison like the photos above.
_________________ Mind f**k!!! it works on feeble minded ignorant sheeples... there's plenty of em on this site... some are very intelligent but by god they are so thick!!! {USERNAME} wrote: You can buy them seppertly
|
|||
| Top | |
|||
| SWC |
|
||
|
Hope to have 91AA cut this week, both Exhaust & Intake ports.
|
||
| Top | |
||
| Who is online |
|---|
Users browsing this forum: Facebook [Bot], Google [Bot] and 59 guests |
