94 octane is the highest available around here without heading out to the track, and the stations that sell it do so at the same price as 91 anywhere else.

I don't suppose you can you give me any sources to the head and piston information?

We're gonna take the engine apart next weekend (so, on the 29th) and the guy helping me said we'd take a look at the cylinder walls; says if it doesn't look too bad it's probably better to just leave it alone. Says he knows of a few people who had nothing but problems after rebuilding a motor that was already running good.

Still, I'll keep it in mind and ask about it at the shop that's going to put it in for me.

The battery's been disconnected for the past year, so no worries there. I'll get looking for the ECM a bit later today.

 

i redid your calculations. from what im finding, the piston to deck clearance is .025 and you entered negative. from what i found they are flat top pistons, so all your other numbers are correct. it came out to 10.97:1, which is right at the limit of 94 octane. my car is running 10:1 and requires 90 octane, but i usually run 92 shell v-power. with it being fuel injected, it can handle a bit more compression as it can self adjust the timing to prevent knock. and with compression that high, you had better invest in a serious radiator and fan setup. im running a griffin rad, rated to 450 hp, and 2 fans- one is 1600 cfm, the other 1200 cfm, and its still runs very hot even when its 75 degrees out. im sure your car will run hot as well with an even higher compression. you may be able to find thicker header gaskets, i think the zz4 motors use a .050

 

Would you say a radiator is something critical that I need to address right away, or would it be alright to leave that for a little while until I have money to spare again?

Additionally, what about double-stacking the head gaskets as suggested by the person who's going to help me do my heads and cam? Good idea, or bad?

 

No, I wouldn't stack the gaskets, you could be leaving yourself wide open for a blow out. You can get head gaskets in different compressed thicknesses, as well as with slightly different bore diameters. Both of those factors will change your static c.r. Lemme run some numbers on D.D...

 

Ok, ran some quick numbers. For the 350, Fel Pro makes a multi layered head gasket with an .040 compressed thickness, and a 4.165 bore diameter. With a stock .025 deck height (taking microkids word for it) it will give you a static c.r. of 10.67. You need to also consider what type of cam you're going to use, as the profile changes your dynamic c.r. (google static and dynamic c.r. and do some reading). Although 10.67 may sound high, the right cam can allow you to need no more than premium pump gas. That c.r. by the way, is right about where my engine is, and it runs great on premium. I actually alternate between primo and mid grade every other tank, and still don't get any pinging.

 

this is an 87 your playing with right? if it is Cut your floor boards out and put some frame in there. If your worried about a rear-end then you can always pull a 9in. ford out of a junk yard have it rebuilt, make yourself some custom supports. Blam O now you ain't gotta worry about the rear-end. btw i haven't read what kind of trans your runnin yet. what is it?

 

Those sound very similar to the ones I've got- Felpro, bore of 4.166, and 0.039 thickness. I will have a look as to this dynamic thing though.

Stock 700r4, although I'm having it rebuilt when they pull the 305. The issue right now is money- I can cover the swap and the rebuild on the transmission, but then I have to wait awhile, 'cause I'll be out of spare cash. So for now I want to just do the bare minimum I can get away with and then maybe look at doing more over the winter or something.

 

Unfortunately, you already bought your heads. Other than having a less than optimum intake runner size, the 60cc combustion chamber is a bit small for flat top pistons, unless you want to have a 12:1 compression ratio. Compensating for a potentially high c.r. by using thicker, larger diameter head gaskets, compromises your "quench" area. What would have been better, from a performance standpoint, would be to have the block decked .010-.015, and use larger chamber heads. Of course, if your engine actually has dished pistons, that would change things different still. After your head stops spinning from the c.r. differences, give this a read and see if you understand what I'm referring to about quench. Piston Head Clearance Guide - Tech Article - Chevy High Performance Magazine

 

it all depends also when you tear into the motor. if its beat and needs rebuilt, then i would suggest getting dished pistons and then run the smaller head gaskets. but its good to know what you are doing before you get into it.

what rad do you have in it right now, stock or a cheap replacement? this is the cheapest quality rad i could find that would support my engine and still fit into the stock rad support. be cool offers one but at more than 2 times expensive. http://www.summitracing.com/parts/GRI-6-282AE-BAX/ i also just ordered these fans for it as it was the only setup that will correctly fit that radiator http://www.summitracing.com/parts/DER-16927/ and is also availible with thermstatic controls. the fans im running now barely keep the temps in check, and thats without it being hot or having the a/c on. i removed the condensor for now and have the front completely paneled off so air can only enter the rad or air cleaner. headers are also wrapped and i removed the weather stripping from the rear of the hood. its a serious issue and for every 15-20 seconds of wot i have to stay out of it for about 2 minutes to cool it off (although, coasting from 100 back to 45 takes about 2 minutes). just some food for thought

 

It's been replaced in the past, but it is a stock radiator as far as I know. For what it's worth, it doesn't get outstandingly hot here- it almost never tops 90F. And I always preferred the windows down over the A/C :P

The intention is to pull it apart next weekend- so I should know then whether it needs rebuilding or not. Would it be a good idea to get a set of pistons regardless?

Edit: Apparently my city sits at 2100 feet- high enough to be considered "high altitude" according to pcmforless' order sheet. I guess I should check that box off too, eh?

Edit 2: I just realized that yes, my car is equipped with MAF. So I stuck that in also. Obviously the stock 3.5" F-Body MAF, right?