Triumph Sports Cars

engine swaps and other performance upgrades, plus "factory" V8s (Stag and TR8)

Go to Thread: PreviousNext
Go to: Forum ListMessage ListNew TopicLog In


wrenchmaster
Charles Cabral

(2 posts)

Registered:
11/06/2012 10:24PM

Main British Car:


71 GT-6 w 215 V8
Posted by: wrenchmaster
Date: November 06, 2012 11:08PM

I just purchased a 1971 GT6 with a 215 V8 and a BW 5spd. Does anyone know what kind of mods can be made to these engines and what kind of HP numbers can be reached?


Moderator
Curtis Jacobson
Portland Oregon
(4576 posts)

Registered:
10/12/2007 02:16AM

Main British Car:
71 MGBGT, Buick 215

authors avatar
Re: 71 GT-6 w 215 V8
Posted by: Moderator
Date: November 07, 2012 12:52AM

Welcome to BritishV8, Charles.

200hp at the wheels is fairly straightforward with simple bolt-on mods. With more radical work (i.e. stroking, forced induction, etc.) the sky is the limit. Remember, your little aluminum V8 has a huge racing heritage: Dan Gurney drove one in the Indy 500 and Jack Brabham used one to win a Grand Prix championship! Your question is one of the main topics of this website. Have a look through our huge article archive (under the left-most pull-down menu at the top of this page) for articles on topics such as camshafts, fuel injection, superchargers, header selection, alternate intake manifolds and carbs, boring and stroking, etc., etc., etc. You'll also want to check out the MGB GT V8 racecar articles on our sister website, BritishRacecar.com. And then there's the "Drivetrain" section of our message board.

Perhaps this snapshot will give you some inspiration:
http://www.britishv8.org/articles/Images-V15-2/Supercharger-A.jpg


TR4AIRS
Kristof Van Pachterbeke
Belgium
(45 posts)

Registered:
12/27/2010 05:58AM

Main British Car:
1966 Triumph TR4A IRS Honda S2000 F20C

authors avatar
Re: 71 GT-6 w 215 V8
Posted by: TR4AIRS
Date: November 07, 2012 06:26AM

That is one awesome engine bay!


wrenchmaster
Charles Cabral

(2 posts)

Registered:
11/06/2012 10:24PM

Main British Car:


Re: 71 GT-6 w 215 V8
Posted by: wrenchmaster
Date: November 07, 2012 09:28AM

Thanks for the INSPIRATION! I will get some pics posted as soon as I can. Looking forward fun years ahead with this car.


triumphtr2
tim body
St thomas ont Canada
(87 posts)

Registered:
08/18/2010 10:21PM

Main British Car:
1954 TR2 serial # TS 110 L triumph 2 litre

Re: 71 GT-6 w 215 V8
Posted by: triumphtr2
Date: November 07, 2012 09:09PM

Curtis. That has to be one of the great pictures of all time. Whose car is that? wow Tim


BlownMGB-V8
Jim Blackwood
9406 Gunpowder Rd., Florence, KY 41042
(6468 posts)

Registered:
10/23/2007 12:59PM

Main British Car:
1971 MGB Blown,Injected,Intercooled Buick 340/AA80E/JagIRS

authors avatar
Re: 71 GT-6 w 215 V8
Posted by: BlownMGB-V8
Date: November 07, 2012 09:30PM

That is Bill Jacobson's car. A very nice build and he runs a Megasquirt-3 system on it.

Jim


Bugeyev8
Brian Marshall
San Leandro CA
(32 posts)

Registered:
12/16/2008 08:53PM

Main British Car:
1960 Bugeye, 1974 MGB,Triumph TR8 1.2 115 Hp 1275 in the Bugeye, Nissan Ka24DE in MG

Re: 71 GT-6 w 215 V8
Posted by: Bugeyev8
Date: November 15, 2012 08:52PM

Ha Ha 200 Hp at the wheels! we have 4 cylinders at the shop that put 440 rwhp !



BlownMGB-V8
Jim Blackwood
9406 Gunpowder Rd., Florence, KY 41042
(6468 posts)

Registered:
10/23/2007 12:59PM

Main British Car:
1971 MGB Blown,Injected,Intercooled Buick 340/AA80E/JagIRS

authors avatar
Re: 71 GT-6 w 215 V8
Posted by: BlownMGB-V8
Date: November 16, 2012 08:58AM

Lovely. I saw a '56 Chevy that had a Merlin engine installed in it.

Jim


roverman
Art Gertz
Winchester, CA.
(3188 posts)

Registered:
04/24/2009 11:02AM

Main British Car:
74' Jensen Healy, 79 Huff. GT 1, 74 MGB Lotus 907,2L

Re: 71 GT-6 w 215 V8
Posted by: roverman
Date: November 16, 2012 11:22AM

Hey waitaminuite, I have Merlin heads for a Rover ! Figure/figure.... about 9,000 HP-right ??


Moderator
Curtis Jacobson
Portland Oregon
(4576 posts)

Registered:
10/12/2007 02:16AM

Main British Car:
71 MGBGT, Buick 215

authors avatar
Re: 71 GT-6 w 215 V8
Posted by: Moderator
Date: November 16, 2012 07:44PM

Quote:
Ha Ha 200 Hp at the wheels! we have 4 cylinders at the shop that put 440 rwhp !

With forced induction.


V8WEDG
Robert Carter
Fremont, CA
(24 posts)

Registered:
11/20/2009 06:03PM

Main British Car:
Poseidon Green '80 TR8 5spd conv, '05 Lotus Elise 6spd SC'd, '91 Volvo 240 wagon

authors avatar
Re: 71 GT-6 w 215 V8
Posted by: V8WEDG
Date: November 17, 2012 03:33AM

Quote:
Ha Ha 200 Hp at the wheels! we have 4 cylinders at the shop that put 440 rwhp !

With forced induction.



Not to mention Hp is only half the story.
V8s generally have much more low end torque and overall area under their torque curves than 4 bangers.
When I dyno'd my mostly stock TR8, I did it at a Miata club dyno day.
despite upgraded carbs, exhaust, and bumped timing, I barely eeked out 100whp.
There were plenty of turbo Miatas there putting down WAY more than that.
However, every single Miata guy there was green with envy when they saw my torque curve, it practically jumped past 100ft/lb as soon as I hit the gas and stayed above 100ft/lb across the entire usable rpm range:
Dynosheet.jpg
show me a 100whp 4 cylinder with this much low end torque and overall area under the torque curve!


Bugeyev8
Brian Marshall
San Leandro CA
(32 posts)

Registered:
12/16/2008 08:53PM

Main British Car:
1960 Bugeye, 1974 MGB,Triumph TR8 1.2 115 Hp 1275 in the Bugeye, Nissan Ka24DE in MG

Re: 71 GT-6 w 215 V8
Posted by: Bugeyev8
Date: November 18, 2012 11:43AM

honda s2k


V8WEDG
Robert Carter
Fremont, CA
(24 posts)

Registered:
11/20/2009 06:03PM

Main British Car:
Poseidon Green '80 TR8 5spd conv, '05 Lotus Elise 6spd SC'd, '91 Volvo 240 wagon

authors avatar
Re: 71 GT-6 w 215 V8
Posted by: V8WEDG
Date: November 18, 2012 01:39PM

S2000? Area under the entire torque curve MAYBE since it revs so high, but low end torque? NO WAY.
First of all, no S2000 dyno graph even goes below 2k, prob because they would stall out below that. My TR8 was spinning the rollers at idle with no gas at all, meaning much more torque at idle.
Second, peak torque on an S2000 doesn't even occur until the VTEC kicks in at high rpm, and is still less than the TR8. Below VTEC it stays between 100-120ft/lbs. My TR8 developed peak torque of 155ft/lbs @ 3k and was above 125ft/lbs from 1200-4200 rpm. That is numerically higher at every point on the graph below 4200 rpm AND the graph extends lower than any S2000 graph.
Third, I see you have a TR8 as well, have you ever driven an S2000? I have, and it's no contest. The TR8 wipes the floor with the S2000 in the torque department.

oh, and I almost forgot, the S2000 is not a 100whp 4 cylinder, it's amost twice that! and still looses the torque battle!



Edited 2 time(s). Last edit at 11/18/2012 02:03PM by V8WEDG.


Bugeyev8
Brian Marshall
San Leandro CA
(32 posts)

Registered:
12/16/2008 08:53PM

Main British Car:
1960 Bugeye, 1974 MGB,Triumph TR8 1.2 115 Hp 1275 in the Bugeye, Nissan Ka24DE in MG

Re: 71 GT-6 w 215 V8
Posted by: Bugeyev8
Date: November 20, 2012 10:51PM

s2k
Leonard-Marshall-S2k.jpg


V8WEDG
Robert Carter
Fremont, CA
(24 posts)

Registered:
11/20/2009 06:03PM

Main British Car:
Poseidon Green '80 TR8 5spd conv, '05 Lotus Elise 6spd SC'd, '91 Volvo 240 wagon

authors avatar
Re: 71 GT-6 w 215 V8
Posted by: V8WEDG
Date: November 21, 2012 04:53PM

You are trying to compare apples to oranges.

1) comparing a highly modified engine (boosted S2K) to an almost stock engine (my Rover V8) [in my response to your original suggestion of an S2K, I was comparing my engine with stock S2K engine dyno graphs]

2) comparing a boosted engine to a naturally aspirated engine

3) comparing a 491WHP engine to a 100 WHP engine when I specifically said in my original post "show me a 100whp 4 cylinder with this much low end torque and overall area under the torque curve"

No one here is arguing that you can't get huge power numbers from boosted engines of any type/size. There have been plenty of boosted Buick/Pontiac/Oldsmobile/Rover V8s over the years that make incredible power too.

The point I was making was, for any given XXXwhp engine, most V8s with XXXwhp will generate more low end torque and area under the torque curve than a XXXwhp 4 cylinder.

The S2K dyno graph you posted above does nothing to refute this point.

Furthermore, despite the apples to oranges comparison you are making, I would point out that my lowly 100whp Rover V8 was already producing 150ft/lbs by 2000rpm, whereas the mighty 491whp s2k engine you posted didn't start producing 150ft/lbs of torque until 2600 rpm, so below 2600rpm, my lowly 100whp Rover V8 engine STILL produces more torque than your mighty 491whp s2k engine. This only serves to re-enforce my point about V8s making more low end torque than 4 cylinders!



Edited 2 time(s). Last edit at 11/21/2012 04:57PM by V8WEDG.



BlownMGB-V8
Jim Blackwood
9406 Gunpowder Rd., Florence, KY 41042
(6468 posts)

Registered:
10/23/2007 12:59PM

Main British Car:
1971 MGB Blown,Injected,Intercooled Buick 340/AA80E/JagIRS

authors avatar
Re: 71 GT-6 w 215 V8
Posted by: BlownMGB-V8
Date: November 23, 2012 10:28AM

What does that s2k do under 2 grand? Can it cruise at 70mph and about 1800rpm? Can it pull a hill and pass at that speed without downshifting?

If all you plan to do is race it might be great. But if you plan to drive it in the real world at all it looks like a pretty severe mismatch.

Jim


pointnette
Stan Thompson
France
(13 posts)

Registered:
11/24/2012 07:56AM

Main British Car:
1999 Toyota Corolla; 1978 Volvo 244 both run bicarburation LPG/petrol

Re: 71 GT-6 w 215 V8
Posted by: pointnette
Date: November 24, 2012 08:23AM

I think this is a bit closer to what you're talking about. It's not stock, but it's not that heavily modified either, which makes it a good 4 cylinder engine to compare with a slightly modded Rover V8.
[www.gomog.com]

Stan


Sorry, only registered users may post in this forum.