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General Category => Triumph Sports Cars => Topic started by: dtindell on September 18, 2008, 06:52:04 PM

Title: 4 cylinder or 6 cylinder for a Triumph GT6
Post by: dtindell on September 18, 2008, 06:52:04 PM
I am thinking of changing my straight 6 from my gt6 to an American engine. Does anyone know the easiest v6 or 4 cylinder with automatic transmission to put in this car? Not worried about power, just want a reliable engine with automatic.
Title: Re: 4 cylinder or 6 cylinder for a Triumph GT6
Post by: dwtr6v8 on September 19, 2008, 07:50:37 AM
Lots of options!

I would go with an EFI system, more work on the install but easy to run , maintain, and service.

A 4 cyl, Toyota 4AGE EFI, Ford 2.3, Honda VTec, although you may have issues with sourcing as you will be completing with the Tuner's out there.

In V6 cyl, a Ford 2.8 or Chevy S10 V6 but you will need to do some oil pan mods.

Don't be too quick to rule out the V8, the Ford 5.0 is small, light weitght, ton of after market parts, and can be sourced just about anywhere in the States.
(I'm bias here)

BritishV8's "How it was Done" section is an excellent resource and ideas as they "have been there and done that"!

http://www.britishv8.org/British-V8-How-It-Was-Done.htm

also at http://www.triumphspitfire.com/engineswaplinks.html

Keep us all posted as you progress!
Title: Re: 4 cylinder or 6 cylinder for a Triumph GT6
Post by: BMC on September 24, 2008, 09:20:51 PM
I did an L32 3.4L V6 SFI in a mid 1970s Spitfire. The problem with an auto is that the pan IS wider than the rails on the far outside! We went to a 5 speed T5 to avoid completely reworking the entire frame. If its got to be an auto to make it easier for the frame, thats in the way you drive it, NOT the way it shifts, but the way you shift it!! If its an auto for a different reason, then maybe thats okay.

If the GT6 frame is that same skinny in the middle 9", then your going to have serious work.

-BMC.
Title: Re: 4 cylinder or 6 cylinder for a Triumph GT6
Post by: dtindell on September 25, 2008, 08:16:42 PM
I am not sure if it is the same frame, does anyone else know? I have seen some how is done with spits and gt6s did they run into the same problems. I prefer an automatic for a daily driver, which is my ultimate goal. Is there any to avoid the problem you mentioned, maybe a 4 cylinder?
Title: Re: 4 cylinder or 6 cylinder for a Triumph GT6
Post by: cooks 7 on October 08, 2008, 01:47:18 PM
I am putting a LS1 (chevy aluminum V8) in a Gt6, so I am biased to the bigger side, but I was thinking about other engines before that.  One option is a Honda S2000 motor, straight 4 rwd oriented fuel injected, light, good power.  Otherwise if you are into American engines, there is the 4.3L v6 from the older cars/trucks, typhoon, syclone, lots of aftermarket parts, it's basically an old school 350 minus 2 cylinders, only problem with these is the iron block, if you are thinking about an auto trans you are adding some more weight as well as having fitment problems, so think about that.  If you go with a run of the mill iron block 4 or 6 and an auto trans it will be a lot of work for not too much return imo.
Title: Re: 4 cylinder or 6 cylinder for a Triumph GT6
Post by: BlownMGB-V8 on October 08, 2008, 03:56:12 PM
It's a GT6 so it really should have a 6 cylinder engine rather than a 4 or an 8. That really leaves you with 2 exceptional choices in an American engine, the chevy 60 degree V6 which has become quite popular, and the Buick V6, one of the 10 best engines of all time. The other guys here will tell you all about the chevy mill. The Buick, ranging in size from 198 cu.in up to 3800 cc has evolved considerably since it's introduction in the 60's and in it's most recent form is a thoroughly modern powerplant. Being a member of the smallblock Buick family it shares common components with them and is near identical in dimensions, missing 2 cylinders of course. It is available with the GM small corporate bellhousing so the newer transmissions will fit, and most of the BOP/Rover swap goodies will work just fine. It is also available with a blower as a factory option.

Jim
Title: Re: 4 cylinder or 6 cylinder for a Triumph GT6
Post by: dtindell on October 10, 2008, 06:47:50 PM
My main goal in th change over will be to make it a daily driver. I am looking to put in a low effort automatic and set it up for driving it back and forth to work. Speed and handling not a major concern for me. It sounds like it will be difficult to put in an automaitc. Does anyone know which engine combo has the smallest automatic transmission? I have seen a posting of a gt6 on this website with a ford automatic. Any advice is appreciated.
Title: Re: 4 cylinder or 6 cylinder for a Triumph GT6
Post by: BMC on October 15, 2008, 08:29:15 PM
All automatics are wider than the Spitfire frame outside the rails!! I suspect that the GT6 is going to be very close to the same otherwise they would have had to redesigned the bodywork and the chassis completely meaning that they may have well made a new car- i would think...

You would have to reorganize the frame and body to get any auto in there. If your going to do that, dont look for the smallest, look for the Smartest!!! The smartest is going to be the right weight, power, gearing and longevity.

As far as an automatic, there are plenty that are reliable but what is the difference? I could start my MGB V6 in 3rd gear without much effort. I could shift from 1 to 3 to 5th if shifting is really a big hassle, but for me, if I think of shifting as a hassle, there are so many other hassles in these cars that i may as well drive a large SUV that will only have issues finding a parking spot in a tight parking lot. If I ever get to the point that I get a bad knee, hip or other driving issues, I may change my mind, but i am not there as of yet. Hopefully this does not sound bitter or corse, it's not meant to be.

-BMC.
Title: Re: 4 cylinder or 6 cylinder for a Triumph GT6
Post by: BlownMGB-V8 on October 16, 2008, 09:47:17 AM
Automatics... yes, I can relate. If you have to sit in traffic holding a clutch pedal down it doesn't take long for an auto to start looking real good.

And the autos in new cars are really really good too. They shift when they should, they shift with the correct firmness for conditions, and they are remarkably efficient. How they got that way is no big secret, it's all in the computer controls. So if you're going that route the sensible thing to do is select a tranny with operating characteristics and gearing that you like and think would be a good match for your GT6, and then learn how to incorporate a suitable controller for it. Some are programmable which is a big plus when it comes time to tune it to your preferences. For GM that would probably mean the 4L60E although there might be another newer and better choice, I've fallen a bit behind on what's available. There are aftermarket controllers for them of course.

I'm stuck with the dinosaurs since I'm using a Buick 340 engine and the newer autos don't fit, but I aim to do some work on the control hydraulics to see if I can set up a shift by wire system. It's a tall order but maybe by next spring I'll have it figured out.

Jim
Title: Re: 4 cylinder or 6 cylinder for a Triumph GT6
Post by: BMC on October 16, 2008, 10:01:26 AM
Jim,

I am not an auto guy and my info is limited but the 4L60 is an earlier version of the 4L60-E. From my understanding, the 4L60 is a renamed 700R4. If this holds true, and if you can get a 700 that fits on your engine, maybe.........

I suppose there would be no such luck.

My next idea would be to create an adapter for a 4L60-E or a 4L80-E to fit behind your system. I would think that would be easier than altering the inside of the box.

-BMC.
Title: Re: 4 cylinder or 6 cylinder for a Triumph GT6
Post by: Bill Young on October 16, 2008, 11:28:50 AM
David, the Spitfire/GT6 chassis is not the easiest to work with for an engine swap. The main problem comes from interference with the steering gear for most swaps. You need a rear sump pan and will probably have to raise the front of most engines above where the optimal point would be to clear. Moving the steering rack creates more problems than it's worth for most people. There are a few Spits and GT6s in the newsletter for reference, but if you must swap then consider a small inline 4 from something like a small Toyota or Nissan along with the transmission of choice. Some of the auto boxes from the Japanese are pretty compact, a trip through the salvage yard with a pad of paper and a tape measure could save you a ton of headaches later. As Don said, the later EFI engines will give you the most reliable car and the best drivability, but unless you're pretty up on electronics and computers you might have problems. If you can find an engine which has been in production for enough years in the same basic form you can usually retrofit the earlier non-computer distributor and intake system if you want and upgrade to the EFI later as you get more experience. The latest engine designs don't have provisions for distributors so if you go with one of these you'll have to use the EFI. I considered a GT6 as a project at one time, but I decided based on the confines of the engine compartment and the "X" form chassis along with the relatively weak differential I'd go for something else that was easier to modify and leave the GT6 stock.
Title: Re: 4 cylinder or 6 cylinder for a Triumph GT6
Post by: BMC on October 16, 2008, 10:57:57 PM
I really liked the way the 3.4L V6 turned out in that Spit we did as far as location. You have to cut the firewall, but it all fit behind the rack, the weight should have been good placewise too.

-BMC.
Title: Re: 4 cylinder or 6 cylinder for a Triumph GT6
Post by: tycorace on October 17, 2008, 01:34:20 AM
here is a thought out of the box .  if you look at a spit and a gt6 frame and compare it to a tr 4 through the tr6 frame.  they are very close to the same wheel base and about the same width and a lot stronger.  they are set up for staight axle or irs . So why try to work with a week frame use one tht will take a v8 with out a major rework.  

mark thompson
Title: Re: 4 cylinder or 6 cylinder for a Triumph GT6
Post by: dtindell on October 17, 2008, 12:45:13 PM
Thanks for the help. Based on what has been posted here, it looks like I will need to go with the inline 4 cylinder automatic. Does anyone see problems with fitting this type of engine into a GT6?
Title: Re: 4 cylinder or 6 cylinder for a Triumph GT6
Post by: BMC on October 17, 2008, 09:50:36 PM
I don't know where your getting the idea that an I4 is the way to go... The auto behind a V6 is going to be no larger, just the same size. The GM 60 degree V6 was designed to be installed into cars that had 4 cyls so they are really no larger.You can fit a compact 60 degree V6 or a 4 cyl. The automatics are all going to require serious frame mods. The GM V6 is going to weigh about the same as a large I4. I4 is good, V6 is good too.

Food for thought.

-BMC.
Title: Re: 4 cylinder or 6 cylinder for a Triumph GT6
Post by: dwtr6v8 on November 17, 2008, 08:05:12 AM
Check out what our fine brothers over at the 6-Pack forum are into.

http://www.6-pack.org/sixpack/phpbb2/viewtopic.php?t=7949&sid=3f1adf204ff5878d122158553e51e31e

If the link does not work go to www.6-pack.org
go to forums
go to upgrades
go to ECOTEC powered Triumph
Title: Re: 4 cylinder or 6 cylinder for a Triumph GT6
Post by: alana on November 17, 2008, 10:35:53 AM
dwtr6v8 Wrote:
-------------------------------------------------------
> Check out what our fine brothers over at the
> 6-Pack forum are into.
>
> http://www.6-pack.org/sixpack/phpbb2/viewtopic.php
> ?t=7949&sid=3f1adf204ff5878d122158553e51e31e
>
> If the link does not work go to www.6-pack.org
> go to forums
> go to upgrades
> go to ECOTEC powered Triumph

To look at a v6 inside a TR, you could go to the guy's site also - http://www.bowtie6.com - there's a lot of good information about the GM v6 in there.
Title: Re: 4 cylinder or 6 cylinder for a Triumph GT6
Post by: Moderator on November 17, 2008, 12:12:49 PM
"bowtie6" (aka Joseph Grant) sometimes posts here too, but he's so damned obnoxious...

I did ask him to write-up a "How It Was Done" article for us, but he couldn't be bothered.

In the 6-Pack forum thread y'all have linked to, he repeated an assertion that he seems to make often... (paraphrased) "V8's are nice but they're heavy, very heavy..." - which annoys me because I don't think he can back it up.

I suspect that the particular (aluminum) V8 that's in my MGB is lighter than the iron-block GM V6 that's in his TR6.

Besides, one could just as easily have ranted: "Triumph TR6 engines are nice, but they're heavier than many V8's..." My point is that whether you install an Ecotec, a GM V6, a Rover V8, or a Ford 302 with aluminum heads - you're still likely to come out lighter than stock. But apparently Joseph Grant isn't will to stop. His own website still erroneously asserts: "As others have done, a possible alternative would be V8 power.  For me that was not an option due to the extra weight.  The mass of a V8 would upset the handling and balance of the TR6 and this was not something I was willing to give up." Bollocks!
Title: Re: 4 cylinder or 6 cylinder for a Triumph GT6
Post by: BlownMGB-V8 on November 17, 2008, 01:28:06 PM
Likewise, Ecotecs are nice but they're weak, very weak ;-P
and custom frames made from 1/8" wall square tubing are nice but they're massive and heavy, very heavy ;-p.

Reminds me of a certain group of BMW enthusiasts who think anything else is crap.

Makes about as much sense, doesn't it? Ignorance is bliss or so I've heard. But on the other hand, to make any real progress sometimes it takes a good set of blinders. Without knowing where someone's going I sure wouldn't try to point out the way. Well, maybe I would but I'd try not to.

Jim
Title: Re: 4 cylinder or 6 cylinder for a Triumph GT6
Post by: danmas on November 17, 2008, 02:07:05 PM
Moderator Wrote:
-------------------------------------------------------
> (quoting Joseph Grant):
> "As others have done, a
> possible alternative would be V8 power.  For me
> that was not an option due to the extra weight.
> The mass of a V8 would upset the handling and
> balance of the TR6 and this was not something I
> was willing to give up." Bollocks!


Double bollocks!

As a matter of fact, a Ford 302 with aluminum heads, complete, ready to run, weighs 35 pounds LESS than the stock TR6 engine. A T5 transmission with bellhousing weighs ten pounds more than the stock TR6 transmission/bellhousing, for a net LOSS of 25 pounds over stock. I know, I weighed them all myself.
Title: Re: 4 cylinder or 6 cylinder for a Triumph GT6
Post by: 74ls1tr6 on November 17, 2008, 09:58:19 PM
I tried to get Joe to do a "How it was done" also. I e-mailed him and asked if I could get information on his rear disk brake conversion with not to much help (because of liability fear), but understood. At that time I congradulated him on a very cool conversion.

Don Watson was more help than I could ask for in the rear disk brake conversion! Thanks Don.

I have been emailing someone out here in Newark, Ca in the bay area, that has installed a Nissan 3000 GT V6.

Photo below. He was interested in a rotisserie engine stand and saw that I made a rotissarie from Bills plans.

This engine may spark interest, I'm sure he won't mind this photo posted. I asked him to start posting and do a "how it was done".


DSC00017acopy.JPG
Title: Re: 4 cylinder or 6 cylinder for a Triumph GT6
Post by: dtindell on November 18, 2008, 06:10:16 AM
Thanks guys, I have looked at a few pictures of gt6s with v8 and v6s along with a sptifires on this site. It seems possible. My dad has been street rods for 30 years and I have seen him change engines several times. Way I see it is if one person was able to do it without destroying the car and my goal is to have a car I enjoy driving, automatic, why not go for it. So I would like anyone not should i do the v6/v8 automatic combo, BUT HOW TO DO IT? Also Does the frame have to be cut if you set the transmission above the frame?
Title: Re: 4 cylinder or 6 cylinder for a Triumph GT6
Post by: Bill Young on November 18, 2008, 08:31:08 AM
David, you could set the transmission above the frame but you'd also have to raise the engine to keep the driveshaft phasing in alignment. That would both lead to a lot of hood interference which somewhat spoils the clean look of the car, but also raises the center of gravity which wouldn't do anything good for the handling. If I was doing the swap, I think I'd take some careful measurments and locate the postion of the firewall on the frame, mark that well, and then remove the body. I'd then weld in some temporary bracing from the front section to the rear to hold the alignment when the center area was trimmed out to fit the engine and trans then weld in the new frame structure and mount the engine and trans. Then you could remove the temporary braces and reinstall the body, trimming that as necessary in the firewall and footwell areas. That would get the transmission located down low enough to keep the balance and driveshaft alignment good and also keep the pan area clear for future maintenance. You stll need to consider a change at the rear though, the stock axle is not very strong and the gear selection is horrible with an automatic. You also would well off to get rid of the rubber joints in the rear axles, much torque and they will destroy themselves in short order anyway. I've heard from Spitfire racers that the rear axle from a Nissan /Datsun 240Z fits pretty well. Check with the Triumph Spitfire racers about this one.
Title: Re: 4 cylinder or 6 cylinder for a Triumph GT6
Post by: scot abbott on January 04, 2009, 04:36:15 PM
What is so bad about the triumph6  in a GT6? The motor is quite solid-although it needs fuel injection to be a great and reliable runner. I fuel injected my son's for a total cost of about $500 and it runs great all seasons. We left the stick alone because the frame rails are toooooooo narrow for an auto tranny to fit. It runs very well and shifts easily.
Title: Re: 4 cylinder or 6 cylinder for a Triumph GT6
Post by: Moderator on January 04, 2009, 08:31:21 PM
QuoteWhat is so bad about the triumph6 in a GT6? The motor is quite solid-although it needs fuel injection to be a great and reliable runner.

How about power to weight ratio? There's a lot of iron in a GT6 (Vitesse) engine, yet it only displaces 2 liters. With respect, no matter how well you tune the EFI system there's still something to that old adage: "there's no replacement for displacement".  The 3.4L GM V6 (for example) is lighter than the Triumph six, yet offers seventy percent more displacement. Some of the other engines mentioned in this thread are even lighter.

That said, Scot, I don't dispute that your work with EFI is noble and worthwhile. If it works well for you and your son, more power to you! I'm curious to hear more about that work.
Title: Re: 4 cylinder or 6 cylinder for a Triumph GT6
Post by: tycorace on January 29, 2009, 11:29:44 AM
what is wrong with the gt 6 drive train , lets start at the front rad is too small needs to be 3 times bigger
 the engine is a good engine but for street use 200 hp is about max (our s had between 240 and 250 hp at 8600 rpm  but idled at 1000 rpm not very streetable.  the trans in racing would go through 3 out of 4 sycros in a race weekend if the gear box lasted.at all.   the drive shaft and axle ujoints are too week for a stock eng torque and the stub axeles and axles get the boobe prize for being almost as week.  If you want to see why I know this this is a picture of a triumph vitesse (gt 6 sedan)  built to compete in the under 2.5 ltr trans am racing around 250 hp with a top speed at the track of 155 aprox mph . thats what is wrong wiyh the gt 6 drive train.
mark thompson
Title: Re: 4 cylinder or 6 cylinder for a Triumph GT6
Post by: J Man on August 02, 2009, 02:19:16 AM
If you ware wiling to go with a GM Ecotec motor you may get lucky and find a totaled Solstice or Sky somewhere. It is a aluminum motor and should have a smaller auto trans (not sure how small) They put out a good amount of HP and would be better for a even more light weight car.
Title: Re: 4 cylinder or 6 cylinder for a Triumph GT6
Post by: pcmenten on October 17, 2009, 02:38:02 AM
I just picked up a Rover 4.0 with an automatic transmission and transfer case. The auto transmission is rather skinny. Wouldn't that fit between the rails of a Triumph?

I don't know if there is a proper tailshaft for that version of transmission, one that will take a slip-yolk of a driveshaft.
Title: Re: 4 cylinder or 6 cylinder for a Triumph GT6
Post by: mgbreis on October 19, 2009, 05:54:36 PM
So, a v8 WOULD upset the "factory balance"; it's too damn light!
Title: Re: 4 cylinder or 6 cylinder for a Triumph GT6
Post by: tbush on July 11, 2010, 09:54:26 PM
I just found this thread, so sorry for coming into it late.
Another option for an automatic is a GM 4l30E. Overdrive in 4th. This tranny came on Cadillacs, Isuzu's, and BMW's. Fabled German engineering, designed in Detroit, and built in France. :0)
You can find it with a GM V6 bolt pattern on the bell housing.
It got a reputation as being weak in the Isuzu Troopers. That car should have had the 4L40E I think.
The pans are still wide for a Spit frame rail and mods will be needed. It isn't as wide as the others though.
Here is a PDF spec sheet:
http://www.unofficialbmw.com/images/BMW_Automatic_4L30E.pdf
Title: Re: 4 cylinder or 6 cylinder for a Triumph GT6
Post by: dadhadaroverp63500s on August 31, 2010, 11:58:59 AM
I'd suggest forgetting a V6 or V8 conversion (V6s are nasty, heavy, complex and don't have the vibration-free balanced nature of a straight-six, and a TR6 just isn't a TR6 with a V8) and do one of the following:

 - Rework the existing straight-six engine
 - Drop in a BMW straight-six (it's been done, there's a TR6 somewhere with a BMW S54 3.2L straight-six from an E46 M3)
 - Drop in a Toyota/Lexus 2JZ straight-six
 - Drop in a Nissan RB-series straight-six

Four-cylinder engines tend to sound dull - the Honda S2000 motor is one exception, mind. Just as long as it revs freely, growls as it does so, and (ideally) pops and bangs on the overrun... Alfa Romeo engine, anyone? There's a 156 in every scrapyard round my part of the world... mind you, I'm on the far side of the Atlantic from most of you, it'll be much harder to get an Alfa motor over in the US!
Title: Re: 4 cylinder or 6 cylinder for a Triumph GT6
Post by: socorob on August 31, 2010, 03:21:17 PM
I believe the honda engine requires you to use the honda factory dash. Google Minx with s2000 motor and you will find a guy putting one in a hillman minx. Awesome build. An RB motor is an engineering work of art, you can get massive power from those, as well as supra engines. The RBs get gobbled up pretty quickly here by people putting them in old Zs. That makes for a beast of a car, a few bolt ons and you have 450 hp. Theres one on youtube that will walk away from a hennessey viper like it has my grandpa driving it. Theres an MGB on youtube with a supra engine on it, maybe you can get in touch with the guy for help, i think hes in Arizona? But a straight 6 would look perfect in there.
Title: Re: 4 cylinder or 6 cylinder for a Triumph GT6
Post by: Bill Young on August 31, 2010, 04:03:09 PM
Whatever engine and trans you select, consider most automatics will have too wide a lower pan to clear the frame rails without some modification and reinforcement. That Spitfire/GT6 frame is pretty narrow in the transmission area. The original 4 speed is pretty small and couldn't drop out from the bottom, has to come out from the interior side.
GrahamBingham-HG-X07.jpg
Title: Re: 4 cylinder or 6 cylinder for a Triumph GT6
Post by: spitfire79 on March 03, 2012, 10:23:39 PM
placing a 1993 chevy S10 V6 2.8 in a 80 spitfire, after ive converted it to a carb setup, (old school) from the trottle setup,  with a T5, hoping not to make any mods to the firewall,  ive read that the oil pan has to be modified?  in what way?
Title: Re: 4 cylinder or 6 cylinder for a Triumph GT6, David ?
Post by: roverman on March 05, 2012, 04:19:19 PM
Are you still there ? I'm not on a rant, so maybe I can address your original question ? How about an automatic transaxle ? Lot's of them out there. You might want to look at those with a rigid mounted torque tube, between the engine and t-axle. Porsche 924/944 ? 928= too large, for your app. I suspect Jim Nichols(this site), knows of many more potentials.  Come on clan, let's focus here. Good Luck David, roverman.
Title: Re: 4 cylinder or 6 cylinder for a Triumph GT6
Post by: mgb260 on March 06, 2012, 02:18:14 PM
There is an Australian lockout (for RWD)and cover for the Subaru Impezza/Outback AWD transaxle. Used in Beck Porsche Spyder mid-engine. It could be used in rear drive with Torque tube like 61-63 Pontiac Tempest, but seriously I would widen the mid section of the frame and use a 200R4 with Speedway Motors adapter to 60 degree V6. I would then use the Toyota IFS diff in the rear. I have done a article on this site.     http://forum.britishv8.org/read.php?3,22861