Engine Rebuild

Use denatured alcohol or electrical contact cleaner on the MAF sensor.



You can pull the O2's, but they can't really be cleaned. If they are bad, they must be replaced.
 
ShowroomLincoln said:
You can pull the O2's, but they can't really be cleaned. If they are bad, they must be replaced.
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I wasn't gonna try to clean them. Most of the people I know that race change their o2s out around 40k miles and I'm at 42k miles w/ my truck. A friend pulled his outta his truck though and it was badly damaged. I'm gonna see if mine need replacing.



Motor seems to be running better but I'm still too scared to take it to WOT in fear of more detonation and having to replace plugs again. They're a PITA to change.
 
Difficult to change? Is thier something majorly different in the layout of the 4.6L in an F150 rather than a Town Car? I can change the plugs in my 4.6 in 20 minutes or less.
 
Agreed.Use electrical contact cleaner on the MAF. Just dont physically touch it with anything. Only spray it and shake excess off and slide it back in place. Go no colder than TR5s. Test without any chip at all. Just the factory EEC program. The white plugs indicate lean and hot. The crushed,pitted plug is detonation still and you really need to check gap on the new plugs. For stock heat range set all plugs at same gap between .038-.040. You only need a tighter gap if you elevate cylinder pressure. If you have run a leaded race fuel,you need to swap out to new O2s. If you still have isssues,you will need to run a compression test to see if you damaged the valves. If so,its time to pull the heads. Good news is that you will have it narrowed down.



Just hang in there. You'll get it back in line...:up
 
ShowroomLincoln said:
Difficult to change? Is thier something majorly different in the layout of the 4.6L in an F150 rather than a Town Car? I can change the plugs in my 4.6 in 20 minutes or less.
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They're a little more difficult I'd say if you can do them in 20 minutes or less. Took me three hours today. It's not that they are hard to change. Just takes awhile. Lots of stuff to move and lots of tight places to get in. Better have some swivels and extensions. Go look at a 4.6l in an F-150 w/ coil packs.



NozeBleedSpeed, I put the stock heat range plug back in the truck today and put a gap of .040. The truck seems to be running fine. On the way home today I took it up to 3/4 throttle and didn't hear any detonation and the power was pretty smooth. The exhaust note sounded smooth also.



I had the codes read on the truck after I had the plugs changed and the only one that I pulled was for my gears being changed.



I still don't like the way my truck is idling. Just doesn't feel right or maybe I'm paranoid. The RPMs seem to fluctuate(sp?) a little bit.



I haven't run any leaded race fuel through the truck.



I want to listen to it more but at idle it kind of sounds like I have something like valve rattle from the engine. Not sure. It's a sound that has been coming and going recently.



I think I'm gonna go ahead and say cleaning the IAC has fixed the humming noise. I haven't heard it at all since I cleaned it out.
 
I would recommend that you do a compression test then. That would be the easiest way to some kind of evaluation of your valves.

I'll be out of town for a few days if you try to reach me. I'll be back this weekend.

Good luck with the truck.
 
Couple of things that come to mind.



Have you done a compression check on the motor? If not, I would recommend it.



If or when you build your motor



Are you building for a specific HP range?



What type of blower do you plan on? PDB or Centri?



How big a shot of nitrous do you expect to use?



Will your tranny and rear end handle your hp goals?



Cams = Check out VT Engines or Comp cams. Both offer awesome modular cams. I'm going with VT having seen what there blower cams are capable of. You will also need valve springs. Go with Comp valve springs, they retain the stock beehive configuration and can handle a motor up to 8000 RPM.



Fasteners - ARP I would go with both head studs and mains. Usually the rods already have them.



Ford head gaskets are good.



Ford exhaust gaskets are good.



Ford intake gaskets are good.



I recommend replacing the front cover gasket - valve cover gaskets and front seal. You will have to replace the rear seal also.



If you have extra money to spend get some billet oil pump gears. You will also need the Ford High Volume oil pump (basically a cobra pump) but its well worth it.



Oil pan and windage tray are nice additions.



Assembly will have to be balanced. You can buy a whole package Rods - pistons - bearings fully balanced. Then you just need to have the block machined. You will have to punch it out .020" over with these kits.



Hopefully the block isn't damaged.



Did I mention VT Engines. :xyxthumbs
 
Looks like I'll be doing a compression test on the engine then. Probably have to be after this week before I can get it done though.



tjm01, I haven't decided on a specific horespower range I'm building for but it'll be a good bit. I want to figure out what it'll take to get my truck to low 12s and see what it'll take to get it into the 11s.



I'll probably be going w/ the ATI supercharger which is a Centri. I'll probably be spraying a small shot to get the cooling effect from it. I mainly wanna get my power from the boost. Filling up bottles so you can have your full power all the time isn't fun. It'll probably be a 50 shot dry.



They tranny will get a rebuild before the blower/nitrous combo is put on the engine. I'm going to try to pull a 9.75" rear end out of a junkyard. It'll be able to handle the power.



Comp Cam is located right up in Baton Rouge I believe so I can probably stop in and see them.
 
I would do a leak down test and get the oil analysed. This in conjunction with the compression test (wet & dry) should give you a good indication on what is happening inside your engine.



I would also check the wiring harness where possible and clean each connector. Check each one to make sure it is in good condition and replace if necessary.



Dont just think about the engine, think about the entire system. A newly built engine with damaged or out of spec sensors is not going to work well. Also consider changing the water pump, clutch, generator etc, or at least test them.



I would say from experience, whatever your budget is, double it.



Steven
 
Intel486 said:
alright, I crushed a plug today on the interstate at WOT w/ this different chip... not sure what's going on...



Glad I carry plugs and tools w/ me now.
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Did you bend the electrode?
 
For some reason #8 seems to be the single point of failure for power adders.



I had the exact same problem with my blown GT - electrode bent with chips. It ended up that the ringland let go.



I know of at least 2 other 4.6 motors with power adders that had the same symptoms. All of them lost pistons.



Do a compression check on that cylinder first. I had 0 compression when mine was damaged.
 
tjm01 said:
For some reason #8 seems to be the single point of failure for power adders.



I had the exact same problem with my blown GT - electrode bent with chips. It ended up that the ringland let go.



I know of at least 2 other 4.6 motors with power adders that had the same symptoms. All of them lost pistons.



Do a compression check on that cylinder first. I had 0 compression when mine was damaged.
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Thanks for that info... I plan on having a compression test done. A friend has the tester and I just have to get around to finding time that I can pull all the plugs and he can come over.
 
My advice would be to find a local machine shop to reuild the short and heads. You may want to consider upgrading the heads to the '99+ if you do not have them at this time. Another consideration is to look in the local wrecking yards for a 32v motor from a Town Car. You would get a motor that is suited to truck duty, a little better mileage and better performance.



I believe a local shop would be more responsive to any problems that may arrise in the rebuild. But if done correctly, you should have no trouble out of the motor for well over 200K. You may want to check www.hardcore50.com for info on the mod motors. H-beam rods may not be necessary as they could outlive the block in the event of catastrophic failure. Strong rods are important but they need not be stronger than the block. That way you spend the money where it needs to go, not where it is unnecessary.





Michael Means
 
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