2001 Screw w/ 5.4 motor. 110k miles.

Remote mount turbo w/ 7psi of intercooled boost.

No compression on 3 cylinders, misfire on two. Removed one spark plug from misfiring cyclinder and the tip/electrode was half disintegrated. I think it got a bit hot. Once motor is running I'm going to have to double check the boost levels and the AFR's to diagnose what caused this.

I know this sounds crazy, but I have enough power. I'm considering a built bottom end (rods/pistons) for strength/durability ... with a fairly stock top end. (two reasons: cost of the mods and cost/effort to retune).

I've tried searching ... lots of engine builders make expensive high hp motors. I'm looking for something more reasonable. Suggestions?

Thanks, lugbolt

 

Question...

Have you determined the reason for the low compression? If its burnt valves and the block is fine you can save some money but only taking care of the heads.

Its extremely hard to answer your questions with a sense of whether the answer is accurate without knowing your budget and how much horse power the engine is putting out. Was it ever on a dyno with a wide-band O2?

Also, is it a Lightning, Saleen or Roush? If not, probably best to head down to the supercharger/turbo charger forum section and post there.

 

Thanks Ken. I'll try the super/turbo forum ... didn't see that section. I figured guys around here would be most familiar with FI issues and built engines.

I haven't put a good quality bore scope on it ... given what it did to the sparks plug, I'm assuming piston damage.

I was making about 320 rwhp/440 torque.

lugbolt.

 

Oh, don't exactly have a budget. I figure cheapest I can do this for is $2k for a used 5.4 engine, plus about $1k for install. I'm considering spending more for some insurance:

- a rebuilt under warranty motor
- a motor with a strengthened bottom end.

lugbolt

 

$2500 sale for a built shortblock.
Where are you located?
http://www.modularmustangracing.com/...hortblocks.htm

 

Thanks S.A.L. That looks like a definite possibility. I kind of want to find a longblock ... I think I could do the swap myself, but that shortblock (600hp capable) seems to be about the right strength level.

Denver, CO.

 

Sounds like it could be a number of things - timing, maf and/or a intercooler pump (if you have one) issue to me... http://i155.photobucket.com/albums/s...22-07_1233.jpg thats a picture of my spark plugs half burnt off. ended up being mixed with a bad intercooler pump, timing and problems with the maf

And this is what it will do if left unresolved...
http://i155.photobucket.com/albums/s...23-07_1415.jpg

..yes that is some of the rod and piston in the background

 

Yep, that was what my sparkplugs looked like.

Well ... there don't seem to be many 5.4 crate longblock options out there. It came down to two options:

- a rebuild by local highly reputed shop
- spend $1.5k to $2k on a used motor and hope/pray

I decided while motor was out, to apply the $1.5k towards a built motor.

Manley rods/pistons, arp studs, stainless valves and stiffer springs. I'm also buying a wideband o2 and boost gauge (zt-2) to check the tune and keep track of things.

All this money ... and at this time it won't yield any additional hp gains.

lugbolt