What is the reason that you want to leave the motor in? If the cylinder head is removed, then you already have your fluids drained and the majority of the engine harness is pulled back. The only thing keeping you from pulling the motor is dropping the trans and disconnecting the A/C if you have it. I can understand not wanting to do that, especially if you didn't have all the tools you needed on hand, but a couple extra hours of work seems worth it to me to allow this work to the motor to be done on an engine stand vs. on your back under the car.

 

The OEM head gasket is the most reliable. I've used them on my built bottom end and stock bottom end with up to 20psi. Some have gone more. Controlling detonation should be your focus, not the head gasket material/brand. So in other words boost up to a level that your tuner is comfortable tuning you to on the fuel you be using, there is a safe window to work with and if he is good he will be able to find that. If your going to use after market lower compression forged pistons, then you have to iron sleeve the block. From the sounds of it you don't want to go to those lengths, so if the bores check out after measurement and condition, then id just stick the stock pistons back in, or the Male 9.5:1 if they don't require re bore. Stock rods are pretty darn strong, ive had no issues taking my F22 to 9k regularly. However over time the added stresses can start to ovalize the bores 'in theory. But that's maybe 80-100k + miles and usually something fails first on a boosted motor so data is slim to none there. At 8500rpm, this is the equivalent piston velocity as a F20 at 9k, so its totally acceptable with stock rods if that's the redline you are sticking with. ARP outfit for the bolts isn't a bad idea since you are in there. Both the head and the con rods.

And ps your gas station sucks. 93 is otherwise great.

 

The stock engine is very strong. I do not recommend aftermarket Pistons are rods if your engine is in good condition. I would just pull the head and install the stock head asked and go for a retune. Also aftermarket forged ok tons are not compatable with stock rods. They must be used with aftermarket forged rods. I do it recommend building the engine unless your going for over 700whp.

 

The issue is that he's running pisswater on factory compression on above 14psi. The people that make 700 are on E85.

 

Obviously any 4 cylinder engine Making over 500whp is not running 91/93octane pump fuel. But 400-500whp is pretty standard for straight low octane pump fuel 91-93octane. 90% of people over 500whp with a 4 cylinder engine are on e85.

 

You say its not the head gasket we say other wise. This is nothing like any Miata motor BTW. Im making on over 400whp on "pump 93" gas here in Miami Florida. My car gets beat up at homestead, sebring and PBIR with over 100* ambient summer days with no signs of detonation.

I agree retune and new head, and OEM head gasket should be all you need. Plenty of setups over 400 for years now on un opened motors. Me being one of them


Not true. Im running factory compression at + 16 psi for over 3 years now. My car sees more track and auto x than regular street miles.

 

You're running a supercharger. You see peak boost at redline. He's running a turbo.

 

South Florida here. Turbo 14psi for years. Stock block no issues. That being said the drop in pistons still require the block be checked for being in spec ie not slightly egged and typically rehoned before installation. So regardless block is coming out unless you are able to do that stuff yourself. That head gasket is trash. Install oem and check compression. We all agree it should be good to go after that.

 

Absolutely no issue doing any of the machine work myself. What I don't have is time to spend on this car.