We installed the Alaniz head and drove it for a couple of weeks. The valve train is quieter (IMHO) and this may just be better valve adjustment.

As noted in earlier threads the final combustion chamber size was considerably larger than stock so the final compression ratio ended up being lowered to about 10.5:1. One-half point in compression is going to cost in the neighborhood of 6 horsepower by most guestimates, possibly more. This puts the Alaniz head at a distinct disadvantage before ever turning the key.

Please note: This head could have been milled and the ratio returned to the stock 11.0:1 but I am going the Vortech route and didn't want the compression returned to factory values. I know this messes up the results some but we feel if you add 6 horsepower it will be close to correct.

Shawn made sure the temperatures were correct before the pulls. There were several pulls and I only have one pull from each session. I don't know which ones they are. I do not know if Shawn will use these pulls or others in the final report so his data may differ from mine some.

Peak (8300 rpm) the Alaniz head increased the horsepower by 4. It fell below the factory head at V-tec (6500 rpm) but caught right back up by 7400 rpm. When it dropped a few horsepower post V-tec the torque surged ahead by about 4 ft lbs.

Over the entire rpm range the AFR was 0.5 points leaner with a spike to 0.7 points leaner from 8000 rpm to redline. This thing has room to breath.


I have purposely not given absolute numbers. It eliminates

The question is How many horsepower will the Alaniz head give?
I would like to offer a SWAG: Four horsepower peak plus 6 horsepower for compression ratio loss = 10 horsepower.

I would think the Alaniz head is good for at least 10 horsepower and probably more NA. This particular head was designed for the Vortech supercharger with 0.5mm oversized stainless steel valves, deshrouding of the valves and massive exhaust porting. Less was done to the intake side since the supercharger dominates there. If I was going to stay NA I would have had him open up the intake more. That should have allowed a couple more ponys easy.


The car was running stock ECU, cat, intake and exhaust. The car does have cooling mods. Union Oil 91 octane premium and CastorOil 10/30.

Check out that porting work:

For the few:

Thanks to Tony Fuchs for the install.
Thanks to Shawn Church for the extensive dyno time and advice.
Thanks to Joe Alaniz, a true artist and air flow technician. Unfortunately Joe is a thief and you should avoid doing business with him.

 

thank you phil, for sharing with the rest of us hopefuls.

enjoy your head

 

Finally some info! Thanks alot for the write up... I'm sure we all appreciate it!!

 

Whereas the work for hp ratio looks a tad high I think it might be an excellent move for a forced induction project. I think I'll look at something similar in the future for my beast.

 

Thank you for the write up, many of us have been waiting a while for this. Good luck with your future projects.

 

 

awesome!! where do I sign up?

 

Thanks for the highly anticipated write-up! You gave a very good summary of gains. Just out of curiosity, is Shawn's writeup going to include the actual dyno comparos?

Thanks again! Hope to see another writeup when you get the SC installed!

 

Sorry, my scanner is down so you will have to wait for Dr. Dyno to post chapter 3. He will have some dyno graphs and has been known to share.


I've added a Proflow and Mugen ECU and it feels even stronger. I know it's running even leaner because the EGTs went up at both highway speed and WOT.

 

with the lower compression head, how much boost are you planning to run?