[mach1soldier]

Hey guys, need some thoughts on my build that I am getting parts together for. This is for an automatic mach1 that I don't want to shift past 7000 RPM. It will be run on e85.

Iron big bore block
Lightweight diamond or je pistons (flat top)
manley connecting rods
stock cast crank
Deck the block down to zero deck
Stock 03 mach1 heads or 9 thread heads

My questions are: What cams should I go with? I don't want to lose all my midrange torque but would like good power between 3000-7000 rpm max.
How high should I go on the compression since I'm running e85 12.5-1? or higher? I'm thinking 13-1 would be totally possible.
Ported short runner intake or stock ported intake?

This car is a 90 percent track car but I am not using a transbrake and I do drive it on the street occasionaly.

[na svt]

Zero deck, .036" head gasket, flat top w/4cc valve relief, and a 46cc combustion chamber (.030" off the head) will result in a 11.8:1 CR, .060" off the head will give you 12.6:1

-8" short runner because stock runner length kills power at 6300
-no more than 230 deg intake duration, off the shelf cams won't work well because the LSAs are too wide, need custom grinds
-pistons need valve reliefs to allow for the most optimum intake lobe center

Could easily see 425rwhp/380rwtq. Stock runner length will increase torque but power will fall off after 6300, a short runner will peak a couple hundred RPM higher and power will not fall off more than 20rwhp by 7k and tq will be lower.

[SWEET2KSTANG]

the 4.6's are almost 0 deck as it is, no need to really worry aboyt decking the block. you can take some off the heads, just make sure you have a way to adjust the cams in. depending how much you want to take off the heads, you may need to have the ports matched back up from intake to heads. if you wanting to go to the 7k mack, you will need a modified intake like stated above. another option is to look into an aviator intake, or aftermarket.

[na svt]

Originally Posted by SWEET2KSTANG the 4.6's are almost 0 deck as it is, no need to really worry aboyt decking the block. you can take some off the heads, just make sure you have a way to adjust the cams in. depending how much you want to take off the heads, you may need to have the ports matched back up from intake to heads. if you wanting to go to the 7k mack, you will need a modified intake like stated above. another option is to look into an aviator intake, or aftermarket.

You can cut the deck/heads a combined .030" without causing any alignment issues, any more and the the front cover will have to be cut and the heads/intake aligned.

Cloyes multiple keyway cam gears will put the cams where they need to be. They should be used to degree the cams anyway.

Avaitor intakes are terrible unless highly modified and the Sullivan is only good for 281ci engine seeing rpms over 7500 and larger cube engines. like a 324, going over 7k.

[SWEET2KSTANG]

a modified aviator is fine, and not too terribly hard to modify. with him already having a 4v, i too suggest just having the stocker modified for the needs. as for the deciking, i didnt know what the intended outlook was for how much was going to be taken off.

[na svt]

Originally Posted by SWEET2KSTANG a modified aviator is fine, and not too terribly hard to modify. with him already having a 4v, i too suggest just having the stocker modified for the needs. as for the deciking, i didnt know what the intended outlook was for how much was going to be taken off.

The aviator intake requires a lot of welding/modding on the upper in order to adapt a 4v throttle body, and the runners just flat suck. I've done two avitator lowers, they did work great but took many hours to complete, i can make an 8" c head intake in fewer hours for less money and make more power.

You can cut the heads .060" if you know how to get everything back into alignment.

[mach1soldier]

My goal is to be close to 13-1 compression. I didn't think about the alignment issue though.

What are your thoughts on having the pistons above deck .010-015? I heard that it promotes better flame travel and a couple other things but I don't really understand that part too well.

[na svt]

Originally Posted by mach1soldier My goal is to be close to 13-1 compression. I didn't think about the alignment issue though. What are your thoughts on having the pistons above deck .010-015? I heard that it promotes better flame travel and a couple other things but I don't really understand that part too well.

Having a negative deck clearance doesn't promote flame travel in itself. What does though is gaining compression through means other than domed piston.

Here is what it would take to get 13:1 with flat tops:

Piston to deck..........-0.011
Gasket thichness........0.038
Valve notches / Dish...4.000
Volume of head.........42.000

Compression ratio......13.000

This will require the front cover to be machined and the heads/intake to be machined so that their ports align.

[mach1soldier]

Bumping this for a question since I am about ready to start buying parts. What all needs to be machined on the heads/intake so that the ports align? Is it widening the holes on the intake since the intake bolt spacing is being pushed further apart?