Alternative Engines

[samp5679]

Could anyone advise on alternative engines thats not too much of a chew to fit to the stag not a Rover talking about something with a bit of clout chevy Small block ?

[mjheathcote]

Anything you fit is going to be a bit of a chew, unless you can buy a 'fitting kit'.
If not Rover, don't know anyone who is offering a fitting kit for anything else presently.
I guess for simplicity, the small block Chevy or Ford have been done before.
More complex would be something like the Lexus.
Personally would look at something like the LS1, but nothing is going to be straight forward!

[wilf]

Anything you put in with substantially more power than the TV8 will show up issues in the rest of the drivetrain - diff/driveshafts etc.

I have seen other classics of the era in the USA that needed substantially strengthening to the bodyshells to take the torque of Chevy or Ford small blocks.

[mike@thenook]

Probably an easier job to buy a Mustang, strip the outer panels off and replace with Stag ones

May need the arches widened a little...

[Andrew S]

Don't forget to modify the the rear hubs!!!! Otherwise the rear wheels will be overtaking you instead of you overtaking other cars

[Motorsport Micky]

Could anyone advise on alternative engines thats not too much of a chew to fit to the stag not a Rover talking about something with a bit of clout chevy Small block ?

Given the power and torque you can get prettily easily out of an EFI Rover 3.9 litre what do you want to put out ? As said if you start going above the 350 hp you'll be chasing the power and stressed caused failures down the driveline and then across the driveshafts to the wheels and through the suspension and then into the shell ! My avatar was clocked at 4.6 secs to 60mph (limited to 7" wheels and tyres) and that weighed in at 950kgs.
My own preference would be the Lexus, lovely engine and when you've sanitised the fitment into the Stag should be very reliable.

Micky

[jakesmig]

Don't understand the " not a Rover talking about something with a bit of clout " bit, how much grunt are you after, and if you get it, can you handle it. My R 3.9 chucked out over 200BHP at the wheels before it was taken off the road for a resto, and with bigger headers, a better exhaust and proper top end tuning it will put out more when it returns. If I was greedy and wanted more I would chuck in a 4.6 out of a Range Rover but IMO it is almost quick enough with the 3.9.

"Anything you put in with substantially more power than the TV8 will show up issues in the rest of the drivetrain - diff/driveshafts etc." I use the standard diff and driveshafts and so far haven't had any problem, mind you I don't drop the clutch from standing although once moving anything goes and the rears tend to spin up occasionally without any apparent adverse affect.

Joihn

[samp5679]

Don't understand the " not a Rover talking about something with a bit of clout " bit, how much grunt are you after, and if you get it, can you handle it. My R 3.9 chucked out over 200BHP at the wheels before it was taken off the road for a resto, and with bigger headers, a better exhaust and proper top end tuning it will put out more when it returns. If I was greedy and wanted more I would chuck in a 4.6 out of a Range Rover but IMO it is almost quick enough with the 3.9.

"Anything you put in with substantially more power than the TV8 will show up issues in the rest of the drivetrain - diff/driveshafts etc." I use the standard diff and driveshafts and so far haven't had any problem, mind you I don't drop the clutch from standing although once moving anything goes and the rears tend to spin up occasionally without any apparent adverse affect.

Joihn

Interesting John, I think any other big chevy engines going to be major work maybe a 4.6 RR engine would suit without to many mods to the drive train

[wilf]

Don't understand the " not a Rover talking about something with a bit of clout " bit, how much grunt are you after, and if you get it, can you handle it. My R 3.9 chucked out over 200BHP at the wheels before it was taken off the road for a resto, and with bigger headers, a better exhaust and proper top end tuning it will put out more when it returns. If I was greedy and wanted more I would chuck in a 4.6 out of a Range Rover but IMO it is almost quick enough with the 3.9.

"Anything you put in with substantially more power than the TV8 will show up issues in the rest of the drivetrain - diff/driveshafts etc." I use the standard diff and driveshafts and so far haven't had any problem, mind you I don't drop the clutch from standing although once moving anything goes and the rears tend to spin up occasionally without any apparent adverse affect.

Joihn

John - the truth of the matter is that to get a RV8 to output torque anything like approaching a very mildly tuned Chevy 350 or Ford 351 costs a great deal of money. As standard, Ford and Chevy small blocks are dirt cheap torque monsters compared to the RV and TV8s, and that's before you get into modding them. And let's not get into big blocks..........(aka boat anchors, lol)

[flying farmer]

From what I have heard over the years, anything more than a 3.9 Rover is going to need a complete change of drive train. I remember reading of a small block fitted to a Stag back in the 80s, and the owner broke 5 diffs within the year. Then of course the braking system will need to be totally redesigned, and before you know it you have a totally different car with a Stag shell.

Bullstarz is doing an interesting turbo Lexus conversion at the moment, not exactly a weekends work!
Neil

[jbuckl]

As already mentioned......

The 'torque limiter' in a stag is the diff....

The standard engine made 170ft lbs torque which is increased by the gear ratios & if auto, torque converter and was able to cause fairly early life diff wear.

Cheapest grunty power would come from an old nascar r5 powertrain ($8K) or LS4 (4inch bore) or LS7 (4.125inch bore). Whole car needs to be built for this, not just an engine & brake conversion.

'Nicest' retro modification would possibly come from a 32v stag V8, which I did start to design and build....but paused when i asked myself why...and can I justify spending £12k just on the sprint heads, welding, essential new cams & primary (cam) drive (contra-rotating) alone, before manifolds etc. (budget was for hardened & ground helical gears at the front, chill cast / steel billet camshafts & a 300amp AC welder, although slightly cheaper duplex sprockets might have worked at the front.)

Then I went and bought an old, very low mileage AMG, with electric metal folding roof & 0-60 in about 4.5 seconds.....awesome, but as low as 8 mpg.

[new to this]

Could anyone advise on alternative engines thats not too much of a chew to fit to the stag not a Rover talking about something with a bit of clout chevy Small block ?

if you wanted to fit a ford v6,i have a fitting kit

dave

[davidf]

'Nicest' retro modification would possibly come from a 32v stag V8, which I did start to design and build....but paused when i asked myself why...and can I justify spending £12k just on the sprint heads, welding, essential new cams & primary (cam) drive (contra-rotating) alone, before manifolds etc. (budget was for hardened & ground helical gears at the front, chill cast / steel billet camshafts & a 300amp AC welder, although slightly cheaper duplex sprockets might have worked at the front.)

I would so love to see that project come to fruition. In 1963 the whole concept was to design the slant-4 and V8 together sharing components and development technology. So the development of the Sprint engine should naturally have progressed to a 32-valve V8. Never thought about the problem of one cam having to rotate the opposite way; that would be interesting!!

[Ian928]

I would so love to see that project come to fruition. In 1963 the whole concept was to design the slant-4 and V8 together sharing components and development technology. So the development of the Sprint engine should naturally have progressed to a 32-valve V8. Never thought about the problem of one cam having to rotate the opposite way; that would be interesting!!

I would also have liked to see a Stag Sprint engine!

Too bad Triumph engineers did not have this in mind when they created both engines. My Porsche 928 is designed so there is just one cast for the LH and RH head, and the same cast is also used on the Porsche 944 slant-four (928 Four-valve head below).

32vHeads1.jpg

[mole42]

ISTR that, sometime back in the last century, I was appraised of a set of Works drawings for a 32-valve variant of the Triumph V8....