Supercherger

[feeninpeece]

The typical Jag intakes are backwards... with the TB at the firewall.

There are some older threads in the Performance section. IIRC... a couple people made it work.

Just to be clear, I do plan on doing this with a gen 1 ls. The tb is already at the firewall. My main concerns were what manifold setup i could use. It would be more cost effective to make a custom one, because then i could get any blower i’d like, right? Has anyone ever heard of someone lowering the cr?

 

[04_Sport_LS]

Well as some of the threads linked to here... point out that the 4.2 STR had a lower compression ratio... you might want to look at the engine specs. I dont remember if that was done with a shorter throw crank... or the rods. Either way, the pistons won't work in a 4.0 or 3.9 ... due to the larger bore.

The only option you might be left with is under driving the SC.

 

[ajv8]

the 4.0 AJ26/27 has a wraparound intake at the firewall like the gen1. the
XJR and STR 4.2 are front fed like the gen2. the denso ecus are very smart and adapt to all kinds of mods, i have no idea how the pcm150 works.

i think the easiest way to do it is get a complete used AJ27S and convert it to use AJ30 sensors and accessories

 

[HRLNKN]

The AJ-V8 4.2L supercharged engine blocks also had piston oil jets. None of the NA blocks, except for the AM-V8 in the Aston Martin V8 Vantage, had them. Good luck

 

[ajv8]

the 4.2 also has forged pistons. if you want to support 500whp+ you need a 4.2 block. but with an old eaton the 4.0 block won’t struggle at all.

i know you can use 4.0 components on a 4.2 block and heads if you port and drill new holes. the intake ports and bolt holes changed (like the gen1 AJ30 to gen2 AJ35). the lower manifold from the AJ27S should fit into the gen1 linc head.

 

[DeviLSh]

@dwiggy got the blower working in his gen2 motor swapped, gen1 LS. Search his name, he gives great pictures and info, albeit somewhat incomplete he has shown its possible to get the blower on the motor, among other things. (used a mustang v6 manual trans to convert his LS to manual too)

Sounds like the OP has a gen1. I would try to find a pull-out from an STR and just get that stuff to work in the LS, then use all the resources/knowledge and CNC learnings to maximize that powerplant vs trying to adapt the gen1 3.9 to take on a supechager and factor in all the "math" of adding boost to it. Both are challenging paths no matter what. But the 4.2 starting point seems safer/better.

Either way good luck and document your progress. While I'd like to take HRLNKN's bet, I have more to gain from seeing this pan out than predicting its unsuccess, haha.

 

[feeninpeece]

@dwiggy got the blower working in his gen2 motor swapped, gen1 LS. Search his name, he gives great pictures and info, albeit somewhat incomplete he has shown its possible to get the blower on the motor, among other things. (used a mustang v6 manual trans to convert his LS to manual too)

Sounds like the OP has a gen1. I would try to find a pull-out from an STR and just get that stuff to work in the LS, then use all the resources/knowledge and CNC learnings to maximize that powerplant vs trying to adapt the gen1 3.9 to take on a supechager and factor in all the "math" of adding boost to it. Both are challenging paths no matter what. But the 4.2 starting point seems safer/better.

Either way good luck and document your progress. While I'd like to take HRLNKN's bet, I have more to gain from seeing this pan out than predicting its unsuccess, haha.

I appreciate your optimism. It is what it is and like all projects this one may get abandoned, but for now i’m not gonna enthuse the people on this forum who always seem to bet against people like me. I know this is a commonly frowned upon decision with this topic, but it is in my best interest to conserve my money. I’d like to retain the 3.9 block. I didn’t know that the aj27s lower manifold would work. My question is If i get the lower manifold including the runners to the heads and the split pipe under the charger, would I be able to use any eaton blower? Also where would this leave me in terms of snout distance. I do intend on doing this with the gen 1 engine. I think it will be easier than the gen 2 because of the lack of dbw and way more electrical garbage. Also no VVT.
On an unrelated speculative note, if you guys remember that polish guy Jajo that swapped a 4.2 into his gen 1, he used intake cams from the 3.9 and exhaust cams from the 4.2. Or maybe the other way around I can’t remember. I don’t remember him explaining why he did this, or if he kept the sc at all (i’m gonna revisit that post after this) But maybe this was to eliminate the intake exhaust valve overlap after the exhaust stroke? If so, wouldn’t this be much better for a boosted engine?

 

[feeninpeece]

After some more reading i’m confident that the only way this can be done safely with a gen 1 without pulling the block is with head spacers. More questions. How would this affect timing with the chain and all that. would the tensioners do their jobs? Would i need a longer chain? Another thing i’m unfamiliar with is how is boost controlled with a supercharger? Oem systems never have bovs or anything like that. It’s connected mechanically; is there a clutch or something? I know on the jag eaton units there’s a vacuum fed bypass for uncharged that can be converted to electronic actuation. This is probably in my best interest I believe. I’ll be having this tuned by Torrie until I confidently learn how to tuned.

 

[ajv8]

On an unrelated speculative note, if you guys remember that polish guy Jajo that swapped a 4.2 into his gen 1, he used intake cams from the 3.9 and exhaust cams from the 4.2. Or maybe the other way around I can’t remember. I don’t remember him explaining why he did this, or if he kept the sc at all (i’m gonna revisit that post after this) But maybe this was to eliminate the intake exhaust valve overlap after the exhaust stroke?

that was a 4.0 NA from an 00-02 S-Type, he did it because he locked up his block. the S-Type AJ28 is the closest relative to the Gen1 3.9 (AJ30), it uses ford PCM150 management and sensors like the LS instead of the denso equipment on the AJ27, the main difference is that it has VVT actuators in the head.

You can convert a VVT head into a non-VVT head by swapping the cams and plugging the VVT oil passage. This is how the 4.0 motor is swapped into a 3.2 XJ8 that has no-VVT controls, or how you can use an NA head on a supercharged block.

 

[feeninpeece]

What do you guys think?

 

[feeninpeece]

gonna have to convert the flanges on the intake mani. to a gen 1 bolt pattern

 

[oddball]

Surprised no one mentioned this, maybe I'm the only one that's been around this long now (besides Joe)??

QwikLS did this with Jag parts back in the late 2000's on his Gen 1 LS. He posted a ton of good stuff here on the site about the conversion. I don't think he posted how he got the ECU tuned - there aren't many folks paying attention to this ECU - and the main interesting note is the Gen 1 injectors are "air assist". You need to get standard injectors if you replace the intake manifold with a normal manifold or a blower/manifold combo.

Strongly recommend you get a Jag blower from the early 2000's that bolts on.

Boost on a blower is controlled by a bypass valve built into the manifold. It serves the exact same purpose as a BOV - recirculates air around the blower instead of pushing into the engine - and is normally plumbed up the same way (uses a vacuum source immediately behind the throttle body). The amount of boost is primarily controlled by the pulley ratios, so it's a bit harder to tune boost levels than on a turbo.

The engine can't take much boost, so the compression ratio doesn't matter all that much. The bottom end isn't all that strong, so you can only add maybe 100hp before you start throwing parts out the side of the block. This isn't an LS engine or a Ford Teksid block.

Anything is possible with time, determination, and money. I helped my buddy supercharge a '99 Town Car, fer crying out loud. But this junk is complicated.

A rear toe rod broke on Qwik's car on the highway, caused a bad wreck. He walked away, but the car went to salvage and Qwik moved on to smaller and faster things.

 

[04_Sport_LS]

I forgot about that.

 

[ajv8]

Strongly recommend you get a Jag blower from the early 2000's that bolts on.

Boost on a blower is controlled by a bypass valve built into the manifold. It serves the exact same purpose as a BOV - recirculates air around the blower instead of pushing into the engine - and is normally plumbed up the same way (uses a vacuum source immediately behind the throttle body). The amount

The engine can't take much boost, so the compression ratio doesn't matter all that much. The bottom end isn't all that strong, so you can only add maybe 100hp before you start throwing parts out the side of the block. This isn't an LS engine or a Ford Teksid block.

not true... avos ran a 4.0 block (cast pistons) well past 500whp. many others are 400+ on KB blowers. you’re not pushing anything to the limit with an old heaton.

 

[clubairth]

For more background here are a few things about Quik LS SC LS.
Quik LS

This is the very long build thread and really interesting too!
Supercharged Ls V8
A video of the car.


Here is an LSX version built by a different guy.


Go Big or go Home I say!! 8000 rpm shifting and a big ass blower too! Too bad no 1/4 times?


Plus the turbo versions that have been done?
Rear mount turbo kit lincoln ls
This is the big one from ILLS
Turbocharged Lincoln LS Build Thread...Pics and Vids Inside...

ILLS and Quik LS were the 2 guys who really pushed the envelope on the LS. Both long gone and on to other cars/projects.

I would spend more time researching and asking questions about what has been done instead of reinventing the wheel?
.
.
.

 

[04_Sport_LS]

After some more reading i’m confident that the only way this can be done safely with a gen 1 without pulling the block is with head spacers. More questions. How would this affect timing with the chain and all that. would the tensioners do their jobs? Would i need a longer chain? Another thing i’m unfamiliar with is how is boost controlled with a supercharger? Oem systems never have bovs or anything like that. It’s connected mechanically; is there a clutch or something? I know on the jag eaton units there’s a vacuum fed bypass for uncharged that can be converted to electronic actuation. This is probably in my best interest I believe. I’ll be having this tuned by Torrie until I confidently learn how to tuned.

Oh boy. Now you are falling into the rabbit hole.

 

[04_Sport_LS]

Quote:

"But maybe this was to eliminate the intake exhaust valve overlap after the exhaust stroke? If so, wouldn’t this be much better for a boosted engine?"

Exhaust valve overlap helps draw in the intake charge, which makes more power.

Guys in the 60's were playing around with this idea long before automotive manufacturers started using the idea in more recent years.

IIRC... Chet Herbert was one of the first to custom grind cams... and roller cams at that.

 

[feeninpeece]

anyone got gen 1 ls crank pulley dimensions?

 

[feeninpeece]

 

[ajv8]

main problem with that setup is the intercoolers

the old body XJR had the intake run across the side of the engine bay.

the STR and newer XJR had the intake come right through the middle

 

[feeninpeece]

yup, that’s why the intake piping is going to be one of the craziest parts of this build.

 

[ajv8]

here's how ford made it work

 

[AmsterDutch]

Are you looking at something like this?

 

[SultanGris]

Are you looking at something like this?

View attachment 828576806

View attachment 828576807

Wonder how that works, stock radiator is barely adequate, make it smaller and add a supercharger and twice as much heat generation, hows that work out? LOL

 

[ajv8]

Wonder how that works, stock radiator is barely adequate, make it smaller and add a supercharger and twice as much heat generation, hows that work out? LOL

the same radiator is used on and also is the trans cooler on my 400hp STR. even at 220k miles it runs at 95C no matter the weather.

all it has is an extra intercooler heat exchanger up front. it’s more than adequate. i know people with 550+ at the crank still using the stock radiator