Mach 1 short block

[Stumbaugh]

A friend of mine has an 03 Mach 1 5 speed car. Well he has finished up his teksid 5.1 stroker build for his car. I was asking him what his plans were for his stock short block, he said he planned on selling it to me. lol. Well, I am interested in this motor because mine has 142,000 miles on it and I have been spraying it for the past few miles or so.

Here's my question, would this motor make anymore compression than my stock 4.6 does? I am looking at keeping this a N/A-No2 car for now, so the more compression the better. I know the cranks in those motors are good, what about the rods and pistons? Just any info on those motors would be helpful.

 

[ninjastang125]

Yes it will bump the compression. The rods are powdered and pistons are hyperjunk...

 

[DOHC otto]

Stock Mach compression is 10.1:1 so it will be more than your stock compression. If it was an 5 speed it has forged kellogg crank, rods are pistons aren't forged but are good for around a 150 shot.

 

[Stumbaugh]

I knew the Mach's had higher compression than the regular 4.6's, but I wasnt sure what the cc difference was in the cylinder heads. I am really hoping to be able to achieve somewhere around a 10:5 compression.

 

[trinity_gt]

The stock PI piston has a 17cc dish and the chamber is 42cc giving a 9.7:1 compression ratio. If you put a 42cc PI head on a Mach shortblock which has a very small piston dish (3cc) you'll end up with a very high compression ratio of about 12:1.

It's going to require a good tune to stave off detonation on pump gas with a 2V head at that compression ratio...

 

[nickmckinney]

Notch the pistons, install a real cam, there is a replacement forged rod that doesn't change the balance on the crank that much you can swap in as well. Then you would have a killer 2V.

 

[Stumbaugh]

Notch the pistons, install a real cam, there is a replacement forged rod that doesn't change the balance on the crank that much you can swap in as well. Then you would have a killer 2V.

That's pretty much my game plan. I might have to talk to you about the cam set up, I am looking at turning some RPM's on spray. I am wanting to spin the motor high enough to put good use to a Victor Jr intake...

 

[GoBabyVroommm]

Good luck with it but on a 150 shot i riped the rod from the piston on my 99 4v. IMO if your at the short block get some new rods and pistons.

 

[nickmckinney]

That's pretty much my game plan. I might have to talk to you about the cam set up, I am looking at turning some RPM's on spray. I am wanting to spin the motor high enough to put good use to a Victor Jr intake...

If you are going to spray and the bores are good you need to get a forged piston as well. Manley and Icon have them in the stock bore size for a reasonable price and lighter weight as well.