miata2fast

iTrader: (2)

I will give you the benefit of the doubt, but I still think you may need to tone down your goals. A camshaft with that kind of duration will not work with HLAs. Go with a smaller cam.

My advice to you is to not get carried away with building a monster motor that spins a high rpm that the rest of your combination will not work with. Monster motors need monster transmissions, rearends, suspension and saftey equipment. Start out with a well rounded combination of parts that all work together. A good example, is if you have a very high reving motor, you will need to change the rear gear ratio to make it work properly to your application. I have a pretty mild cam, but to get it to really work with the horsepower and application, I had to put a lower gear ratio (4.44:1) If the bugdet does not allow you to invest in your diff, you want to run a milder cam. Same goes with valvetrain components. Do not go all out on one thing, and skimp on another. You will have wasted money, and your car will not perform as well as someone who went with a milder setup, but has all the parts working together.

Also, you need to gain experience before going crazy. You will learn the hard way that radical motors do not fair well with tuning mistakes. Gain experience with a mild set up, and then when you have the know how, go big.

dc2696

iTrader: (2)

All that head work and retaining those heavy hydraulic lifters...If your buildig the head you better have an equally well flowing intake manifold ( ie custom)

E-NA6CE

iTrader: (2)

Yeah I've been talking with Kelford and they want to cut cams based on what my target numbers are and my powerband. And you don't have to give me the benefit of the doubt, I was just being a douche, ha ha. Giving half-assed information will lead to posts like yours, which is perfectly fine and expected, since I gave half-assed information, ha ha.

I already have a Quaife gearset (which should off-set the rearend, given the higher-than-factory engine RPM), 1.8 flywheel/clutch get-up and the suspension should hold enough of its own until I need a new set. As far as safety equipment, I can put my bolt-in back in until I get a weld-in setup.

Yeah I skimped on the engine this time around, which is why I'm not at my ideal power numbers, which is the reason for this build.

I hate tuning. I'm letting the shop do that. That way they can front money for a rebuild if anything goes wrong (I already checked and they don't have any sort of waiver).

Of course. I know the HLA is around a pound or so of mass, but if what I want can work with the OEM setup I'd rather not swap out to a solid setup and shims. Pain in the ***.

sn95

iTrader: (2)

I know you don't want to hear this BUT:

If you really have high power goals, you start with the engine combination that has the best stock airflow and the best potential airflow (in NA/NB Miata land, that is a 99+ head and solid lifter cams (fitted on your 1.8 block of choice). Engine power and torque is always capped by how much air the cylinder head(s) can flow regardless of whether the motor is NA or FI.

Given how much better the NB 1.8L head flows vs. the NA 1.8L head (which flows significantly better than the 1.6L head), I really wonder why people bother with "big builds" on 1.6L heads unless they are racing in class that specifically limits them to a 1.6 head on a 1.6 block.

If you want a inexpensive, badass 1.6L motor, destroke a 1.8L NB to 1.6L! It'll make more power with a stock head than a fully built 1.6L core and be a lot easier and cheaper.

krash

It may sound like sacrilge to some but if you want high rpm low torque high hp why not save yourself a lot of machine work and just put a rotary motor in it.

E-NA6CE

iTrader: (2)

I never thought of this. That's a pretty good idea. Why the hell do I never come up with good ideas when it comes to my own stuff? FML

I thought about it and was swiftly reminded how much I hate rotaries when I got stranded on the highway in a friend's FD. No thanks.

gnx7

invest in an ATI harmonic balancer. They are the best and for a high revving motor you need to keep vibrations under control....

E-NA6CE

iTrader: (2)

Done and done.

ctdrftna

iTrader: (1)

ok i think im one of the only people on here with a seriously built head.
although mine is a 99, same things should apply. also i work for a race machine shop.

as far as your springs are concerned. you cant choose springs before a cam, thats not how it works. your cam manufacturer will give you spring requirements for that specific cam.

i am running integral R1 exhaust cam and R3 intake cam.
my gross cam lifts are .490 intake and .458 exhaust.
my cam sheet has all the info i need to run these cams. they are rated for 9000 max rpm

the spring requirements for these cams are 49lbs closed and 156 lbs open. that isnt alot of pressure. i have supertech dual springs. i had to remove the inner spring because it was way to much pressure something near 200lbs open. so i use just the outer spring and a shim to make the pressure right, its been a while but i think i set them up around 160lbs open. its important not to run an over agressive spring with agressive cams on a flat tappet lifter like ours because you run the risk of rounding over the cam on initial start up.

before you choose cams you need to have an idea of what your head flow. i have access to a flow bench so i flowed my head to get exact numbers to choose cams. for example. my head flows 246cfm at .500 lift@28"h20 . after that it fell off. so thats why i went with such a big intake cam to have the valve operating where the head flows best.

everything has to work together. a word to the wise, anyone planning on running high rpms. you have to address alot of areas, its not a matter of making your head work in the area, you need strong rods, a balanced bottom end, the lighter the rotating assembly is the better. billet pump gears,and a ati balancer. and NO!!! hydro lifters. when you put in massive cams your motor has the potential of becoming interfearence.

Sparetire

BUT. How do you like the setup? Are you NA? What sort of abuse does the car see?

ctdrftna

iTrader: (1)

i havent fired the motor yet, i can just give advice on building. the car is track only. turbo 400+ hp goals with power up to 9000rpm. im very close to running. but NA or turbo doesnt matter. the heads would be identical for that operating range.

Savington

iTrader: (31)

You're talking about custom high-lift cams, 5-angle valvejobs, knife-edged and balanced crankshafts, and the ~$500 retail conversion to SUB is going to put you over budget?



Projects like the one you are talking about do not get built on budgets. From all the parts and such you just listed, I'd estimate the price tag to be somewhere north of $10k, probably closer to $13k depending on who's doing all the work. The adhesion to the hydraulic lifters is a bit confusing.

E-NA6CE

iTrader: (2)

I'm sticking to the HLA because this is still going to be somewhat of a DD until something else goes into it. If something goes wrong with the SUB assembly it's a PITA to correct, unlike the HLA. I'm not going to knife-edge the crank anymore because it's not ideal on an engine that I don't plan on rebuilding that frequently. This project is on a budget as a whole, not just the engine. To convert to SUB where I am isn't exactly 500 bucks. The dealers in Canada like to fist their customers in every orifice.

ctdrftna
I've took other members' advice on the cam situation and I'm getting one of the local race shops to build my head. I have all the parts for the bottom end but I'm having a bitch of a time finding a forged crank for this car. Other than that everything's forged.

webby459

iTrader: (8)

Yeah, among us here on the forum we've had literally hundreds of bent cranks.

E-NA6CE

iTrader: (2)

That's what's prompted me to do this. I built a half-assed bottom end and you should see how much my pulley wobbles.

gospeed81

iTrader: (51)

I think that was written in sarcasm font.

You don't really need to worry about the crank, although an ATI damper would be a good investment.

If you are getting into the unexplored territory where the crank is an issue you should be building something different, like an FE3, anyways.

webby459

iTrader: (8)

fanboi

ctdrftna

iTrader: (1)

our cranks are forged from the factory. maybe your looking for a billet crank. the diffrence being our cranks are pounded into shape, and something like a moldex crank is machined from a solid peice. it sounds to me like your in a bit over your head. i would stick to some pistons and rods and a nice refresh on the head with maybe some mild port work and good valve job. make your self something reliable. and forget trying to extract performance from every nook. i think if you want NA performance your in the wrong car. our heads are no where near a stock honda head, your not gonna make 200 whp out of a 1.6

E-NA6CE

iTrader: (2)

NA = Bad

Turbo = Good.