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Triumph Stag Engine

Posted by mgguythorn 
David Thorn
Carthage,MO, USA   usa
Our 71 Stag is ready for an engine overhaul or replacement. I would like to stay with the original engine, however the parts are quite expensive for an engine that wasn't very good to start with. Is there conversion kits to put in a Rover or small block GM or Ford engine? Also the steering rack is starting to leak has anyone replaced the seals in their rack and how hard is it?
Thanks

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bernard lanigan
montgomery al, USA   usa
1976 MG MGB "The B"
years ago the buick 3.8 V6 was a common swap...try Johns garage in dallas tx as he sold/installed many swaps on jag /chev and other brits/gm engines...
phil carson
oregon, USA   usa
i don't think that parts are all that expensive. try wedgeparts, they should be able to provide most of the engine mechanicals -- since a lot of the parts are shared with the TR7 slant 4 engine.

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David Thorn
Carthage,MO, USA   usa
I have went ahead and ordered a complete overhaul kit from Rimmer Bros. I know alot of the parts are the same as the TR7, however the crank is hard to locate as ours needs rehardened and turned. Also the timing chains have an upgrade to a German chain set up. All in all the Stag engine was a poor designed, weak, problem prone engine that should have been scraped and replaced with the Rover engine. But our Stag will still be sporting its original engine.
Karl La Follette
Homosassa , florida, USA   usa
The rear end in my stag blew out because of the chevy 350 in it see the gallery of my home page . Gloss over the piks for a couple of my stag . www.fastpitstops.com

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cjcharvet Avatar
Courtney Charvet
Titusville, Florida, USA   usa
My father-in-law has a '73 with a Chevy 327 in it currently.
yellowbookroad Avatar
Gareth T
Somewhere in, Estonia   est
1970 Triumph 2.5 PI MkII "Permanently NICKED Nickname"
In reply to a post by mgguythorn All in all the Stag engine was a poor designed, weak, problem prone engine that should have been scraped and replaced with the Rover engine.

Don't agree at all here. The problem was quality control and is much the same today.
I have rebuilt a few of these, and it's very difficult to get proper work done, and decent bearings.
Let's just look at the list of defects I was faced with, when doing the last one.

Crank had been ground 010 010 and tufftrided. The surface finish was indescribable. I could have reground the crank better with a hacksaw, and that was supplied from what was recommended tothe owner as a "reputable Stag specialist!

It took me more than ONE DAY to polish the journals properly, and that was after taking it to a "reputable" company that said they knew how to polish it...
I was forced to do it by hand, and then I supplied some old stock vandervell bearings for it.

Next the block had been relinered, but no attempt whatsoever had been made to make the liners flush with the block, and both deck surfaces were out of line as was the main line and the bottom of the block.
Result, the head gaskets had blown, and the sump leaked and goodness knows what the clamp load would have been on the head, which also had been skimmed badly and supplied with soft cam followers...

The remanufactured oil pump I was supplied with was crap, and the tolerances were basically "out of tolerance" and the crank was quite out of balance.

Once these things had been sorted, like any decent V8 engine it has been totally reliable and thrashed constantly around Europe at 90-100mph in the hottest temperatures that can be thrown at it.

SO please stop knocking this engine, it's only because the vast majority of bodgers including a fair number at the factory were clueless about putting them together
(just like another UK engine called the Rover K series btw).

Once you blueprint and balance a stag engine, then build it properly, it will take all manner of abuse without a single hiccup and on top of that doesn't have camshafts that fall to bits or drink petrol like the ancient Rover V8 always did.



Edited 1 time(s). Last edit at 05/08/2011 03:55PM by yellowbookroad.

triumphguy Avatar
dave roberts
loveland, colorado, USA   usa
I had a Stag with a Buick 3.8 in it. It was pretty decent once it was sorted. Big problem with this motor ()or just about any transplanted to a Stag) is it's height. Unless you fab up some sort of snorkle to relocate the air cleaner you'll need to cut the hood. Intrestingly enough, the 3.8 is a cast iron variant of the Buick/Rover motor. If you are intrested in going the Rover route, contact Glen Merrick. He's on the British V8 website. His car is pretty kick-butt. I know someone who put a SBF in his Stag. The oil sump/pump is in the front of the motor causing clearence issues with the x-member. Only bad thin I could thing of with the SBC is the clearance between the distributor and the firewall. If I was going to do a swap right now, I'd go with an LT1. Very compact, it has strong aftermarket support, stand alone EFI, etc... Makes a little bit too much power for the rear end, IMHO, but is that a bad thing? grinning smiley
Paul Monat
Northborough MA, USA   usa
Yellowbookroad.....agree 100%. Have many friends with great original stag V8s with NO PROBLEMS. I'm picking up a short block from a guy who did a good job on that, did many. I'm hoping to avoid problems having the heads done right. Any suggestions on technique?

Sparrow010 Avatar
Andrew Gaskin
feilding, New Zealand   nzl
1974 Triumph Stag "Staggy"
After compairing the cost of doing a re power to the cost of a full re build of original Stag engine, I went with a Toyota 1UZ- FE quad cam V8.
Fuel injected 4.0 with 260 HP.
Staggy now has new lease on life :-)
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DSC_0894.jpg (40.4 KB) –
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britsnspits Avatar
Michael Stoliker
Bethlehem, PA, USA   usa
1976 Triumph Spitfire 1500 "The Phoenix"
1978 Triumph Spitfire 1500 "Lucky"
That must have taken a large shoehorn.

Sparrow010 Avatar
Andrew Gaskin
feilding, New Zealand   nzl
1974 Triumph Stag "Staggy"
No more tight than fitting a rover V8 into a stag.
Diff is now a Ford 9 inch. Nice and strong and lots of ratios to choose from.
rrascal Avatar
Russ H
Hawkes Bay, New Zealand   nzl
Hope you upgraded the brakes as well...



Edited 1 time(s). Last edit at 06/13/2012 06:56AM by rrascal.

Sparrow010 Avatar
Andrew Gaskin
feilding, New Zealand   nzl
1974 Triumph Stag "Staggy"
Sure did. I fitted the vented front 4 pot and rear disc brake kits from Monarch stags in UK. I also fitted there BMW Servo and master cylinder up grade Kit. Nice to have good stopping power.
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stag history 160.jpg (42.6 KB) –
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foxy osborne
gwynedd, United Kingdom   gbr
1971 Triumph Spitfire MkIV "SPITTY"
1972 Triumph Stag "Stag"
Hi, I've recently finished 1800 miles after a Stag V8 rebuild ........ the most important feature is a revised cooling set up with a high level header tank from Chris Spain [uk] which incorporates a low coolant level warning on dash --- brilliant, & at about £130 british £ worth every £. I would NEVER fit any other engine than it's correct V8 [bear in mind if you change engine the suspension / brakes / steering will need sorting. My "new" engine is running so well, often do 200 mies a day touring Welsh Mountains around here.Can email pictures of the work in progress if interested.
STEERING , well, I fitted a recon steering rack from James Paddock [uk] very low price & now works well.
All above went so well, I didn't need the "SPARES" Stag I bought, so am now selling it on.
SO, STAY STAG stay Stag V&
Foxy

britsnspits Avatar
Michael Stoliker
Bethlehem, PA, USA   usa
1976 Triumph Spitfire 1500 "The Phoenix"
1978 Triumph Spitfire 1500 "Lucky"
Foxy,

Over in the US, Stag spares and Stag engines are hard to come by and very expensive. If an engine swap and upgrades keeps the car on the road, I'm all for it. On the other hand, I do like to see a well restored Stag with the original engine. They are beautiful cars.

Mike
foxy osborne
gwynedd, United Kingdom   gbr
1971 Triumph Spitfire MkIV "SPITTY"
1972 Triumph Stag "Stag"
HI again, are you aware of RIMMER BROTHERS ??? Based in uk they do sell spares WORLDWIDE and their unit prices are very good, they specialise in Triumphs & do a free [plus post] catalogue which has brilliant "exploded view" illustrations of all parts, so helpfull in restoration. You can also get this on CD or on line. TRY THEM. tel +44 1522 568000 email sales@rimmerbros.co.uk website www.rimmerbros.co.uk transactions by card, cheque, transfer -- bt in british £ Another good uk supplier worth contacting www.jamespaddock.co.uk
I used to make the Hardtops for MGB & SPRITE/MIDGET [the factory ones that came with new cars] which were the ONLY MG Hardtops legal to export to California, so agree transport to USA can be high, BUT today Rimmers have assured me they can do you a good deal.
Hope this of help. ANYTHING TO STOP YOU FITTING A NON TRIUMPH ENGINE and ruining an otherwise great car. OH and make sure you fit a Chris Spain header Tank to cure overheating [mine was £130 complete with pipeworks.] Photos of this available.
FOXY

gravelsandwich Avatar
Liam O'Connor
Rockhampton, Qld, Australia   aus
I have the same dilemma here in Oz, My Stag currantly has a Rover 3.5 which needs replacing. I would really love to return it back to it's original T3.0 engine but to source one and have it fully reconditioned PROPERLY costs the best part of $10,000. I just keep comming to the Rover 3.5 (or even the Leyland 4.4 unique to Australia).
The other posible engine i'm toying with is a Mercedes 3.8 ohc to keep in line with the triumph 3.0 ohc theme but it would need to be dry sumped and the head hight is doubtful.
twomanytriumphs Avatar
Kyle Darby
SW Washington, USA   usa
1965 Triumph TR4 "My Baby"
1966 Triumph 2000 MkI "Bessie"
1970 Triumph GT6+ (MkII) "The Princess"
I agree with Gareth. The Stag's biggest problem is ignorance and the blame game. To make one reliable, a person must spend copious amounts of money to make them right. Its worse if someone has "fixed" them before. On my mom's stag we ended up sourcing a new set of heads because it was actually a couple hundred dollars cheaper to have a specialist rebuild them and ship them versus the local machine shop to fix the existing ones. As for driving a Stag, it was great. My dad's 73 (he had 2 for a couple of years) was an original, well kept, rust free, original paint Stag. The motor had been rebuilt by a shop in California and the only serious problem the car had in 4 years was the differential went out. A used one in its place and it was on its way. I miss the sound a Stag makes when rolling into the throttle.

Kyle.

mimssandi Avatar
Roger & Sandra Hobart
Mims, Fla, USA   usa
1962 Triumph TR4 ~ For Sale ! ~
1968 Triumph TR4A
Hey, I am in Mims. I build race cars for my friend, Don Loftus. He owns everything. I am the young crew at 63. He is about 72 and has been SCCA for years. We race Bugeye and Midgets. Shop is at Custom Coachworks, next to Anderson Portapotti, across from Pinewood Elem. Stop by anytime you see the chains down and doors open.

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