So what kind of things can I do to add power without simply buying an XJR? I'd like to make close to 400 whp (will settle for 350 since the zf box is made of glass).
I'm guessing the AJ26 can accept larger injectors , and possibly a tune(hopefully without a standalone ecu and tcm). I'm certain the cylinder would have to be bored out. I'm also certain that a set of XJR brakes would go a long way in keeping me alive. To make the power I'm also assuming I'd need a beffier cam , perhaps something mirroring the x300 xjr or maybe I could repurpose one from the x308 xjr. Cooling is another thing to look at , and my chassis has a history with failed radiators; so maybe I could get a secondary oil cooler installed perhaps under the abs module or windshield fluid. Same thing with the trans an external cooler would likely go a long way in keeping it alive regardless of torque gains.

What do you guys think, apart from the fact that with enough money anything is possible. Can the AJ26 be stroked for more torque , and how much power can the zf box handle before imminent manual conversion. My guess is that each cylinder would have to be bored to about 0.6 or 0.8 before it makes any meaning full power.

 

The ZF can handle up to 320 lbft of torque so not much wiggle room there. Most people concentrate on the XJR because 1.) there are easier ways to real power gains such as pulley swapping or new S/C without changing the engine architecture 2.) The MB 722.6 Trans can handle over 600 lbft of torque, on paper at least.

The naturally aspirated AJ26 also is not as stout as the SC variant. I love the AJ V8 but super stout it is not. You might be better off swapping in a 5 liter AJ V8 gen 3 and transmission if you want an NA car, that would yield 385 HP. There would be some compatibility issues I'm sure but no more than heavily modifying your current engine.

 

Well, you are not boring the cylinders because its an aluminum block with no liners, rather the cylinder walls are plated with hard chrome-like stuff called nikasil directly onto the aluminum. The manufacturer did not intend that it could be overhauled like an old Chevy small block. Probably the biggest bang for your buck would be in the exhaust. Its engineered to be a quiet car. If you open up the exhaust with high flow cats, or skip the cats depending on your local regs, and glasspack type mufflers, you might could gain 5 -10 hp maybe. But I haven't read anything on these forums that anyone has done that could anywhere near approach your goals with the original motor. Seems like I read about a company that offered components for an LS motor swap. I think that may be the only way to go and you should search for information on that. However, nearly all of us on here bought our XJ8s for the magic carpet ride, not to go fast, so you're in unfamiliar territory. But I'd skip the AJ133. I have one. After all that effort to swap and then to have it eat water pumps practically every day for breakfast would be depressing.

 

About the only way to go is forged pistons, leave the cylinder walls alone and a wet nitrous setup. That would be the cheapest way possible. Easiest? No.

 

early 5L isn’t a good motor and has nothing in common with the original AJV8s. honestly just spray and pray, otherwise get an XJR

 

It was an all new block design, didn't realize the gen 3 was/is a garbage engine. Love to see someone put the 4.7 Aston Martin AJ V8 in an XJ8, if it weren't a rare item.

 

The AJV8 gen 3 isn't, but you're talking about the old AJ26 NA. Why not go for the improved one... (it can do 700HP or so...)

 

Actually my post was in response to a comment saying the early 5L wasn't a good engine, which would be gen 3. I had never heard that so I was asking. We all know the issues of early AJ-V8s and would be the last engine I would hot rod, not worth it.

 

AJ133 not a garbage motor, certainly a vast improvement in "performance" over the AJ26, however, its equally as fragile or maybe a little more so from a long-term reliability standpoint. But because its the halo engine for their halo sports car and it has a few weaknesses, there are very few available and plenty of demand. And the upkeep is very demanding and expensive. Buying a used AJ133 engine is simply not a cost-effective choice. By comparison, an LS3 brand new crate motor capable of 430hp could be had for considerably less cost than a used AJ133 of unknown service history. That's what I'm kind of rooting for our OP to do. Of course the whole project is not cost effective, but hey, as long as I'm dreaming with somebody else's money........

 

I agree with you, hard to argue with the value of the LS and it's reliable and compact to boot, less moving parts. It's so popular for car modifiers its almost cliché. However I just never saw the AJ as a modifier's engine. I don't think it's that fragile if kept stock. We all keep circling the same point, if you want a cost effective, reliable power gain it probably isn't happening with a NA AJ-V8.

 

I wish I could afford the new xj545 spec gen 3 but leaving cost aside simply finding a downed car with an intact engine and trans, already sounds like trouble. Let alone getting all of the electronics to play nice.