V8 into a Stag

V8 into a Stag

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Ultra Sound Guy

Original Poster:

28,031 posts

162 months

Sunday 15th July 2018
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I absolutely love the Stag, and have owned one. I’m looking for a new project car and want to get a Stag with a normally aspirated V8 with more than 400 BHP
Can anyone point me towards an engine/ gearbox combination which woul not require anybody mods but would allow a decent manifold setup?

//j17

3,708 posts

191 months

Monday 16th July 2018
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If you want 400BHP then you're cheapest/easiest option's probably a Chevy crate engine like an LS3. Plenty of gearbox options for those engines too. not the smallest in the world though so you'd struggle to get it under the standard Stag bonnet line.

Only 250BHP as stock but a few people have fitted Lexus 1UZFE engines, but tunable and fits under that standard bonnet line. The standard Lexus auto box is the easy option, otherwise it's an adaptor plate to a Supra or BMW geabox.

Ultra Sound Guy

Original Poster:

28,031 posts

162 months

Monday 16th July 2018
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scratchchin
Some interesting options there! I guess I'm really looking for a very narrow V8!
Or some 'trick' headers?

Yertis

16,238 posts

234 months

Tuesday 17th July 2018
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Why on earth would you want 400bhp in a Stag? Basically you'll need to build a complete drivetrain and suspension system, then drop a Stag body over it.

//j17

3,708 posts

191 months

Tuesday 17th July 2018
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Why not?

Ultra Sound Guy

Original Poster:

28,031 posts

162 months

Tuesday 17th July 2018
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Yertis said:
Why on earth would you want 400bhp in a Stag? Basically you'll need to build a complete drivetrain and suspension system, then drop a Stag body over it.
And?



//j17 said:
Why not?
Exactly!

I just happen to think that it's a particularly good looking car, just doesn't have enough grunt!

OK, I'd probably settle for 350BHP!

Yertis

16,238 posts

234 months

Wednesday 18th July 2018
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//j17 said:
Why not?
Well basically the reasons I said above. I was kicking the same idea around when I had the Monaro. I like Stags a lot and agree that 145bhp is a bit tentative for the car. So I had a longish chat about it with Roger at Monkfish Performance (who knows his V8s and his Triumphs) and came to the conclusion that the car you'd get at the end would basically be a Stag in outline only. The Stag's a lazy GT and, whilst it could certainly use more oomph, 400bhp is IMO way over the top.

Still, it would be a fun project so fill yer boots! Plenty of cheap Stags knocking about with odd engines. Good luck.

Tony1963

3,152 posts

130 months

Thursday 18th October 2018
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A heavily modified Rover V8?

300bhp/ton

39,671 posts

158 months

Thursday 1st November 2018
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//j17 said:
If you want 400BHP then you're cheapest/easiest option's probably a Chevy crate engine like an LS3. Plenty of gearbox options for those engines too. not the smallest in the world though so you'd struggle to get it under the standard Stag bonnet line.

Only 250BHP as stock but a few people have fitted Lexus 1UZFE engines, but tunable and fits under that standard bonnet line. The standard Lexus auto box is the easy option, otherwise it's an adaptor plate to a Supra or BMW geabox.
Suspect the LS3 is a lot more compact than Lexus lump.

300bhp/ton

39,671 posts

158 months

Thursday 1st November 2018
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Ultra Sound Guy said:
I absolutely love the Stag, and have owned one. I’m looking for a new project car and want to get a Stag with a normally aspirated V8 with more than 400 BHP
Can anyone point me towards an engine/ gearbox combination which woul not require anybody mods but would allow a decent manifold setup?
I suspect you'll struggle to do this without any body mods. 400hp will need a pretty decent gearbox, so chances are the transmission tunnel and maybe firewall/bulkhead might need some work.

No idea if the rest of the car will be up to handling 400hp and the associated torque. I would suspect not.


Realistically you aren't going to get there with a Rover V8 in n/a guise. A real 280-320hp maybe if you are prepared to spend the money on the engine. Which would still produce a pretty rapid vehicle tbh. And obviously the Rover V8 fitment in the Stag is very well established.

A turbo or supercharged Rover V8 could more easily get over 300hp if you are prepared to step away from n/a.

Chevy LS engines are the next most obvious option due to their price and availability. They all make about 350hp + stock for the 5.7 and more for bigger displacements. They are a slightly different shape to the RV8, bigger and smaller depending on which dimension you are looking at. And slightly heavier. Biggest choice would be what gearbox to use.


If you wanted to stick more "Triumph", then you could look at a turbo/twin turbo Stag V8. Saab very successfully demonstrated how good the slant 4 was in turbocharged form. I t would take some R&D, but suspect a turbo V8 could be done. No idea on potential power, but I'd have thought 300hp would be quite possible.


Lots of other V8 engines out there from BMW, Audi, Merc and others. But generally they are all going to be bigger, taller, longer and heavier than a Rover or Chevy LS. And as a rule cost more to buy and tune.

If you don't mind auto's there is the Jaguar AJV8, it's still DOHC, but quite compact compared to some of the others. And is available cheaply in the UK. n/a will be shy of 400hp unless you plan to tune it though.

bullstarz

46 posts

137 months

Saturday 8th May
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Did you make any progress with this project, I know it’s a few years since the last post but only just seen it. I’ve had a Lexus engine in my Triumph stag for quite a few years. I’ve had to update a lot of parts the car including the gearbox and final drive. But with that the engine has also got a big turbo fitted.


samuri

151 posts

190 months

Friday 9th July
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Bought this modified Stag about 14 years ago, running 3.9 Rover with a holley, app. 250 bhp, still going well, love it; just returned from 1500 mile Scottish Highlands road trip.