99 head a necessity for 300whp?
 

Ive search plenty and still no answer. My current setup is a gt2560r @10psi. Car runs 13.4s@104 in the quarter. Im in the process of building up a forged motor for it. This isnt a dream or a maybe someday build. Ive allready purchased a new gt2871r, forged rods, pistons, boundary pump, ati damper blah blah blah

is a stock 95 head that shitty that i wont beable to hit 300whp with a 2871r at a reasonable boost level ?

It has been done many many times.

No, you can make 300hp without a 99 head. The 99 flows better for sure, but the NA8 head isn't going to crush your dreams too badly.

With a turbo build I probably would not bother with a 99 head personally

You should be able to hit 300whp is a 94-97 head no problem. It will probably just take a little bit more boost to do then the 99+ heads.

It's also possible to make 300whp on a 1.6.

It's even easier if you are in Australia.

its like this though, All that money on goodies then stop short of a 400 head?

:likecat:

I'm using a smaller turbo and hitting 300 at 19ish psi on a '95 head for now. 2867r

Yes, better head flows better but he's asking if it can be easily done with what he already owns and the answer to that question is yes.

Remember Eliminator? He made over 500 with the older head. Of coarse, these days it would be silly to try to make that kind of power on the older head unless you just like spending money.

You guys are right. Ive already had plenty of noise from my HLAs after a few passes at the strip. Its time for 99head and solid lifters

You can run SUBs on a 95 head. You might consider learning how to make power with what you have before graduating to a more complex build.

ive read you can run SUB on bp06 heads. I didnt look into it but im assuming you need to change cams as well ? My thought is that using a 99head means less boost for the power id like. Which should equal lower IATs. Im stuck in CA with crap 91 gas

Cams don't need to be changed.

Eliminators was by no means a stock head though.

Buy the 949 CNC heads. They flow best.

Yes, 99-up heads flow better than 94-97 and create less boost to reach same power.

You can run SUBs on any of them.

HLA noise indicates an oiling problem. You will still have an oiling problem no matter what head you use. Fix that first.

HLA can be noisy regardless of oiling, IMO. A pack of old miata after a run sound terrible. They couldn't all have oil starvation, could they?


The 00 head does not add any complexity.

Lifter noise is caused by excessive clearance in the valvetrain. With hydraulic lifters, oil is pumped into the lifter to cause it to expand and reduce excess clearance, thereby reducing noise. Some of the oil pumped into the lifter will bleed out by design. But if the oil is too thin or there is not enough being supplied it can bleed out more quickly than it is replaced. This can cause excessive clearance and therefore lifter noise.

Long branch polymers used to increase the viscosity of oil with an increase in temperature are broken down by mechanical actions within the engine. For cheaper oils with less sophisticated additives this breaking of polymer chains occurs much more quickly. One test cited on bobistheoilguy.com noted a 50% reduction in viscosity extension in an inexpensive motor oil within 2000 miles of operation, to my recollection. So the 10w-30 was behaving as a 10w-20. This is likely why many run-of-the-mill Miata owners report having HLA noise when the cars are overdue for an oil change at 4000, 5000, 6000 miles.

Thinning is also a direct consequence of the oil being hotter, so if you have oil that is old, cheap, too low a viscosity to start with, or all of the above and then run the engine hard it will be more likely to have HLA noise due to inadequate oiling.

If the clearances at the bearing surfaces in the block and heads are greater due to wear, the oil pump is worn, and the lifter to bore clearances are looser than original, the oiling system may produce a volume less than adequate to silence the HLAs. This can of course be exacerbated by oil thinning for the reasons listed above.

Add to the equation partially clogged oil passages due to sludge and varnish in an older motor.

HLA noise is no mystery.

A couple runs of rotella T6 cleaned all the gunk out of my engine and shut up my HLAs. So as long as your engine isn't worn too badly, they should be easy to fix too.

Man, that first change of rotella was nasty. 1000 miles and the oil was black. Now it stays clean for the 5k mile.OCIs I run.

The Lucky Country
 

We are indeed the lucky country!

It adds to the budget and time to source it, the intake, and any other parts needed to make it happen. It was just a suggestion in case the OP's resources are limited. I am certainly an advocate to better cylinder heads.