Xu5ja Head Results

[EdCherry 34 1 Cars]

Well got the chance to superflow the head of one of my XU5JA engines. 87k Miles, not cleaned just as is off the block with headgasket failure. Not the best engineering gone into the adaptor plates but they do the job ok with little leakage which is accounted for in all the results anyway.

 

 

Obviously some of the tests apply to an XU9JA head, but it has a total of 1.8mm lift less than the cam of the XU5JA.

 

Inlet - Well the extra lift of the XU5JA provides barely any extra flow, with only a 3% increase in flow between the cams (roughly based on the results I have, I didn't measure lift at exactly 9.7mm). From about 9mm lift onwards to 11.5mm there seems to be room for quiet alot of improvement, putting the figures against a calculated potential maximum flow the head is at roughly 75% of what it could be, realisticaly your never going to reach 100% but 85-90% would be a nice figure to aim for. Even the lower end of lift has quite a bit of room for improvement hovering around the 80-83% flow rating compared to potential.

 

Exhaust - It fairs pretty well at low lift, proving to be very effective with some flow ratings compared to potential at 93%. Once again at the higher end of lift its got alot of room for improvement compared to potential sitting with 72-76% readings. I wonder if using a larger valve would help this, but I havn't had much of a look at the exhaust port.

 

At some point I will post up some rough results for people to use and make their own conclusion on. The head ive got will be stripped down, cleaned up and hopefully worked at some point later this year, will come back to it and see what I can get results wise. Might even post up my own findings if I find anything significant.

[Baz 421]

Std heads are all different in terms of castings etc anyway, some are shockingly poor, some good! Well, not so bad!

[EdCherry 34 1 Cars]

Cant generalise that much, yes they will all be slightly different, but wont vary widely. First thing im gonna do is find how much of an improvement there is having a clean engine lol!

[Rippthrough 98]

Dremel time!

[EdCherry 34 1 Cars]

Dremel is for a home bodger like yourself phil! Im going to go at it with an air chisel, those parts need to be LARGER

[Rippthrough 98]

Dremel is for a home bodger like yourself phil! Im going to go at it with an air chisel, those parts need to be LARGER

 

Pfft, bet my dremel'd head flows better than your chiseled bath-plug holes

 

Nothing wrong with 400w of axminster multitool for shaping head ports!

Edited June 1, 2009 by Rippthrough

[EdCherry 34 1 Cars]

Mine will flow more than potential once ive finished! Nah just kidding at some point I will get a chance to have a good with my dremel

[Rippthrough 98]

Mine will flow more than potential once ive finished! Nah just kidding at some point I will get a chance to have a good with my dremel

 

And a welder, and a lathe, and some carbide ball mills....

[EdCherry 34 1 Cars]

And a welder, and a lathe, and some carbide ball mills....

 

Well im tempted to remodel the ports completely into triangles rather than rectangles and to make it a pushrod cam instead.

 

Im picking up another engine tonight to play with, going to try a few drastic measure's on the head thats worst off and if anything comes up trumps I can play with it on the good head.

[DrSarty 90 1 Cars]

good head.

 

Mmmmmm....