Hello to everyone. 5.4 Navi Dohc Q.

LIEBREICH

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Hello ppl. Im not sure if this is a right thread or even if this is the right forum but when I google "5.4 dohc" stuff, most of the time Im ending up on this forum ,so Ive decided to register in here. Also wanna apologise for my English because its my second language and my English grammar is lame , so dont throw rocks at me:)
So let me introduce myself. My name is Anton , Im from Estonia EU. Was born in USSR and my native language is Russian. That's it so far :)
Now to my Q's. I have 99 Lincoln Navigator which I bought a 1.5 year ago. After some of the exhaust valves get burned Ive decided to restore my car completely. So now its completely apart in a boxes in my garage. Body of the chassis, gearbox and transfer case on the table getting rebuild. I took engine apart as well , took some measurements which told me that I have to do cylinder boring which means total engine rebuild to me. Heads are in good shape.
In the beginning I was thinking to put stock parts but now I want something better. I dont know many brands who provides performance parts for those engines so Im watching on mmr stuff. Also I have to mension that the engine is gonna be working on LPG as it was before. Bad LPG system adjustments actually the reason of burned valves :) .
This is a pretty rear car in my area so there is no ppl to ask in here what is better for me to do with my engine. I dont have a lot of money to buy some fancy heads right now or even better camshafts but Im looking in future on those. Right now i have many boxes with new suspension parts, new timing set, oil pump, gaskets etc. Body and chassis going to be sandblast as fast as weather will be better. Only question is the engine. Im going to do heads porting very soon. Going to leave stock cams for now. As i already understood , cranks are very good on those engines.
What you guys will suggest ? Does it even worth to buy performance parts for me? Any thought on 4r100 tranny?
Im thinking to buy performance pistons , rings , roads , pins, main bearings and piston roads. Thinking to leave stock heads and cams with all new valves, stock but new rockers and valve adjusters for now. Is it ok to do like that for a year or two so later I can install other performance parts to get more power?
Also what could you guys suggest to do with the engine for LPG? Bigger compression ratio?
Actually I have no hope to get answers but it worth to try to ask at least:)
Here is very few photos of my project . Thanks for your time.
 

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01yellercobra

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I'm thinking you figured out the picture thing as I see some in the first post.

I couldn't tell you about compression as I've never ran LPG. Is is pretty detonation resistant? What are the future plans? Are you just wanting to make it more peppy or are you wanting big numbers with some kind of power adder?
 

LIEBREICH

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Hello 01yellercobra. It is better detonation resistance. There is more benefits to use LPG over the petrol as well. As for numbers , it would be nice to have 100-150 hp later in future.
 

01yellercobra

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Then I'm guessing there's forced induction in your future. So I would build for that. If you have the budget then get the heads cleaned up and ported. A little extra flow never hurts when going for more power. Definitely upgrade the rods and pistons. I'm not sure how stout the 5.4 crank is as I'm a 4.6 guy.

It might be worth posting in the Lightning forum. They should be able to point you in the right direction for the shortblock.
 

CobraBob

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Welcome to SVTPerformance! Interesting that you're running LPG. Is that common over there in Europe?
 

LIEBREICH

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Im goind to do porting work myself. I'm small business owner, fixing cars. Heads already cleaned up.
What pistons and roads would you recommend?
 

LIEBREICH

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Welcome to SVTPerformance! Interesting that you're running LPG. Is that common over there in Europe?
Hello. It's 5 gas stations which offer lpg for sale in my area. All of the in 10 km radius . I think it's pretty popular in here .
 

LIEBREICH

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Welcome to SVTPerformance! Interesting that you're running LPG. Is that common over there in Europe?
I'm running 4th gen of lpg plant 4 gen has its own brain which connected to the pcm . Lpg control module takes orders from pcm . That is simple explanation of how it works.
 

decipha

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when running LPG make sure you run a high pressure system

you'd want static compression around 13:1 which still allows you to run pump gas if need be

by far the best pistons you can get for your setup are going to be autotec/ractetec pistons

you can run scat rods no problem

stock 5.4 cranks are forged, I've pushed over 1200rwhp on a stock 5.4 crank so you should be fine. I have heard of cast cranks but have never personally seen one before and I've built several 5.4's over the years.

the 4r100 trans is a heavy clunky and slow transmission. In all of my harley trucks I've always upgraded to the 4r70w trans. I've blown up several 4r100s I have yet to blow up a 4r70w.

stock cams are fine theres no need to replace them. Some people run the older cobra intake cams and gain a few hp so if you can score them for cheap that wouldn't be a bad idea.

When porting a general rule of thumb is to never cut the bottom of the port.

As you've learned you should upgrade the exhaust valves regardless. I'd recommend some comp 6000 valves or the like.
 

LIEBREICH

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when running LPG make sure you run a high pressure system

you'd want static compression around 13:1 which still allows you to run pump gas if need be

by far the best pistons you can get for your setup are going to be autotec/ractetec pistons

you can run scat rods no problem

stock 5.4 cranks are forged, I've pushed over 1200rwhp on a stock 5.4 crank so you should be fine. I have heard of cast cranks but have never personally seen one before and I've built several 5.4's over the years.

the 4r100 trans is a heavy clunky and slow transmission. In all of my harley trucks I've always upgraded to the 4r70w trans. I've blown up several 4r100s I have yet to blow up a 4r70w.

stock cams are fine theres no need to replace them. Some people run the older cobra intake cams and gain a few hp so if you can score them for cheap that wouldn't be a bad idea.

When porting a general rule of thumb is to never cut the bottom of the port.

As you've learned you should upgrade the exhaust valves regardless. I'd recommend some comp 6000 valves or the like.
Thanks Man. That's a lot of good info you gave to me. I very appreciate it.
I have to run petrol anyway because of car start during the winter.
Do you also have lpg plant on your car?
 

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