Clevo120Y

Cheers Thom and Tony, I have enjoyed sharing especially when you guys show so much appreciation and give great feedback.
I have ported heads on a mild scale for a long time and only had seat of the pants judgement on if it goes better, Porting without a flow bench you really are just guessing, you can have an educated guess and make improvements for sure. Once you use a flow bench you start to find out what was just a waste of time, some of the things I've done in the past didn't hurt flow but didn't improve it either and once I started mapping the port velocity it really only took small changes to the port shape to make a big difference, simple things like throat percentages, blending the seat into the throat and the seat itself are all things that can be done that will give good results without needing a flow bench, plus I will be sharing things that you guys can do at home that I will prove on the bench before posting them up, plus things that I can show don't work to save people some time and money. 
Thanks guys for your interest and positive comments, I have shared things on other forums about what I'm doing but not to the same detail as here as I think this group is the best of the lot and I feel the urge to take the extra time to share the details with you.

I thought I would start a separate thread for the head port I'm working on for the race head I'm going to be doing for a proddy speedway car.
This port is a C1A casting, and the results are using a stock standard crossflow intake valve, 1.8in single cut valve. The port has a 3 angle seat cut that is a little worn but still usable. So the first test was on the port as cast from the factory with the 3 angle seat cut, the second test is with the port ported and the third is with the port work plus the chamber work.
 
this is the stock valve I'm using
 

 
Stock combustion chamber and reworked chamber, not much needed here, just laying the edge over and blending to form a nice smooth shape, you have to take the point off the end of he swirl generator to stop pinging.
 


 
This is the port work, hard to explain what I have done but most of the work is at the short turn and bowl area, I mapped the air velocity of the stock port to determine what material and shape needed to be used, the port responded well to being biased to the right.
 


 
Here are the results
                     test1        test2        test3
50                 29.4         30.95       36.08
100               54            58.34       63.15
150               77.4         85.6         92.5
200               98.5         108.98     121.92
250               121.2       131.56     149.84
300               141.4       151.05     165.2
350               162.9       168.79     178.97
400               177.7       180.13     190.17
450               184.4       189.02     198.22
500               186.2       197.22     202.96
550               189.1       203          207.93
600                               214.2       213.98
650                               213.44     213.4
700                               212.16     212.2
 
 
So as you can see the results are reasonably good, the chamber work plays a big part of the power potential, this head now has a flow potential of 330hp using the stock standard intake valve.
Hope you find this interesting.
 
 
 
 
 
 

I was super excited when I heard it run, it sounded tougher than any of the other 6's there and torched the tyres with ease. Was gutted when he sent me pics of the head LOL. He works at the local wreckers so has plenty of parts to play with, plus I don't charge him much. I do it for the fun and to see how my work performs. I need to find a video to post.

Thanks mate, just saved me time looking for these

Let's talk ignition systems for our crossflows.
I personally have had great success with the TFI dizzy and MSD 6al-2 programmable 6530 ignition system, I found that the features of this system were hard to beat for the price. Rev limit, burnout rev limit, launch rev limit, boost/nitrous retard and a full programmable ignition curve, you can make and save any number of curves to suit different fuel or race conditions, just upload from a laptop.

At the moment the workshop is getting a makeover for the relaunch of "Stumpers Heads & Manifolds" early next year. Something had to go to make room so the XD wagon got the chop for now, it's out at Wombats property, new shelving going up, some new tools on the way and some mould making gear to make carby tops that will be dyno tested and developed for sale later, hopefully a big year coming up.
Also the production XF that I did the head, manifold and carb for last year will have it's first run this weekend so I'm excited to see how that goes as well, this XF has been a back of the field car for years so let's see if we can get it up near the front.

All stock steering mate, the car is totalled by the way he drives lol, it's funny because this car rolls out onto the track that looks like it's just been pulled out of the tip and then proceeds to kick arse hahaha. A few old blokes that were at that meet told me that the bar erupted when he won, they loved seeing the old girl up and about, a lot of them are older drivers that used to race XF's when they were younger.

Here is my youngest boy, he looses his mind everytime there is a race car in the workshop LOL. He knows all the blokes names as well and everytime the phone rings he says "is that Wombat or Wolfy or Corky?" "Are they bringing the race car over?" He can't get enough I have to drive him around in the front yard in them HAHAHA

That's interesting Rob - I must ask Ray about it next time I'm over there.  The Ray Hall one I have has a divided (two hole) plenum and the holes taper into the manifold but it could still do with a bit of tickle around the runner entries.  I'll do that before I send it down to Ryan for testing on 'Patches'.
 
For $50 its gotta be worth a go at least.  Agreed on the four barrel bringing them alive.

Do you still need a fuel pump hole blanking plate? I can send one with your manifold if you want.

6AL-programmable, never looked back. While not quite up there with the tuneability of an aftermarket ecu, they do what they're designed to do, and well. Instead of a 3D map like on an ecu, they have 2 separate curves (rpm and load) that subtract timing from your preset max advance on 2d graphs, to an absolute total of 30 degrees, 25 on the graphs and the other 5 through rpm or switched retard. They have launch retard and step retard functions too, as well as rpm limit. Quite impressive for the money. Need a GM map sensor with it too

I support the vote of no confidence on this unit...had a Ray Hall unit that looked just like it and it was no improvement over stock TBH. Then I went to a Cain 4 Barrel and all of the sudden it came alive

I would put a modified stock manifold in front of that, the air/fuel would shear off the short turns into the runners something cronic. But like the other guys have said, you got it so you may as well try it.

Once he D shapes that plenum entry to the runner and smooths the transition I reckon it will be okay.  I have seem some stupidly ugly, home built manifolds perform way better than you expect them to. 
 
Gotta be worth a try at least...

Did you set both engines on TDC before removing the head?

theres not enough info to realy help. if you have set the engine on tdc and cable tied the chain to the gear if it does not line up you know its the head and just turn the cam till its in the right spot and refit if you have not done that you will have to line the chain up with the engine on tdc and try again

Only cause I run a fraction more clearance but you have proved you can go tighter without issue. Oh and I wont be giving away any measurements - how can I make money selling me oil pumps if I give away all me secrets? Lol.
 
Is that the one I was going to throw across the back paddock - until your massive mitt stopped me.  lol. 

I personally like the 465, great all round size and vac secondaries.

I also agree with stock oil pump, the race engines I built run the same "big" clearance as Ando and the stock pump has plenty of pressure. Ando will give you the measurements for the relief valve, I also do the clearances inside the pump, I run 1.5 thou cover to rotor clearance, that had Ando worried hahaha but all good in the hood.

No worries Gerg, I have one word for you that explains the down size in fuel jet, EFFICIENCY!! Your carb is now more efficient and your engine requires less fuel to make the same power, the booster signal will be cleaner etc etc. this is why when people say that if you have more airflow you have to add more fuel but it isn't always the case, an efficient motor will use less fuel for more power and that's in the forefront of my mind when I do my little experiments.

Good to hear mate and great to see others have a go with positive results

Good to hear mate and great to see others have a go with positive results

An optimised engine will always use less fuel, make more power and torque and run cleaner. Factory setup is always on the very safe side regardless of what you buy as even mass produced performance parts have to be made for the mass market which includes simple holden owners.
Thom I would pick the middle collector.

Good explanation Stumper, I'm pretty stoked too! Just hoping this newfound efficiency shows at the petrol pump... It's been a shocker lately: about 20l/100km

http://www.gumtree.com.au/s-ad/mackay-4740/other-automotive/speedway-extractors/1067156388
 
These would be nice and quiet

No worries Gerg, I have one word for you that explains the down size in fuel jet, EFFICIENCY!! Your carb is now more efficient and your engine requires less fuel to make the same power, the booster signal will be cleaner etc etc. this is why when people say that if you have more airflow you have to add more fuel but it isn't always the case, an efficient motor will use less fuel for more power and that's in the forefront of my mind when I do my little experiments.