rowen210

I am building a 5.0 to put into a Miata and want a little more that stock power. I want the car to daily driver capable, easy to tame, and maybe 250 whp. I normally deal with BMWs and have never owned a push rod engine. Any guidance to get me near my power goals would be appreciated.

What I have:
1993 5.0 HO with 150k miles
1993 Cobra upper and lower intake
1993 Cobra 65mm throttle body
A9L computer
GT40p explorer heads with 120k miles
MSD distributor

What I want:
E303 cam
24lb/hr injectors and MAF
High volume oil and water pump
Fel-pro gaskets

Questions:
I need new springs but what kind and how much lift?
Do I need new pushrods and lifters?
Are stock explorer rockers any good?
You guys are the 5.0 pros so, while i have the motor out what should i do preventative maintenance wise?
Are there weak points in the block I should thoroughly inspect?

aode08

Not to infringe on your intelligence, you have all you need for that little miata.


The GT-40 has been known to exceed 300Ft lbs of torque as it is.Your at 235HP on the motor stock(GT-40),so to get your extra 15+Hp, my guess would be to just add a cold air intake, under drive pulleys, and advance the timing and hold on. You don't need the 24lbs injectors


Don't always look at horsepower.

rowen210

I realize that this will be a lot of tq for such a little car and I will be traction limited but people put beefed up LSX motors in Miata so I don't think 250hp and 300tq is too much to ask. My over all goal is to freak out my friend who has a 2013 GT500. I don't think I can beat him but it would be nice to give him a run for his money.
I forgot that I already have a under drive crank pulley. After I get the cam and springs do I need to upgrade anything else (lifters, rods, rockers)? I don't want to cheap out or cut corners. The last thing I want is to have a catastrophic failure while I'm pulling away from my friends GT500

I do have a new issue... my friend thinks my motor that I bought out of a running 1993 auto vert might be a 1986 motor. It has a the wrong intake plate to be a 11993.a little research told me that in 1986 the HO had flat top pistons so I will know when I pull the heads. But is there a less intrusive way to check the year? Someone told me the code on the motor will say "E" for 80s and "F" for 90s and a single digit after the number designating the year. I cannot find a code on this grease ball motor. Is this code thing true and if so where do I look?

bluebeastsrt

Don't bother with a cam without also upgrading your heads beyond GT40s. Throw some shortie headers on it and you'll be making around 275 at the wheels with a cheap H/C/I kit from trick flow.