• Hi Guest!
    You can help ensure that British Car Forum (BCF) continues to provide a great place to engage in the British car hobby! If you find BCF a beneficial community, please consider supporting our efforts with a subscription.
    There are some perks with a member upgrade!
    **Upgrade Now**
    (PS: Subscribers don't see this gawd-aweful banner
Tips
Tips

Wedge TR7 \ Stag head...

Share this page

G

Greg55_99

Freshman Member
Offline
The first idea was to see if a DOHC Neon\Stratus head could be made to fit on a TR7 4 cylinder block. The second idea was to see if the Triumph Stag 3.0L V8 block could take the Neon\Stratus head on one side and the Eclipse head on the other. Hmmm...

The answer is... well, almost. But I don't think so... Shucks.

The Stag V8 was designed to use the TR7 head on one side and a mirror image of the head on the other to bolt to a common block. Same situation with the Neon\Stratus and Eclipse head... only no common block. The bore spacing between the Triumph and Dodge engines are similar but the Triumph block is not symetric. The spacing between the middle cylinders is different than the outer ones. Shucks.

Well, thanks to a real gent, Mike Sullivan, I got a slightly beat up TR7 head gasket to make some comparisons with. Take a look and see what you think.

Greg

attachment.php


attachment.php
 
nonod.gif
Actually the TR7 and Stag head are not interchangable either.
The Stag head is longer than the TR7 head. Only common parts are the valve components, not even the cam covers cross.
However, there is a Dolomite Sprint 24 valve head that does "basically" fit onto a TR7 engine, but you have to modify so many other engine things like pistons, rods timing chains and such that is us better just to locate a Sprint engine complete.
 
Why do people say the Stag engine is basicly 2 TR7 engines mated together, or that it uses TR7 anything?

The Stag existed before the TR7. If anything, parts of its engine would be compaired to a Triumph Dolomite engine, wich is what the TR7 engine is a development from.
 
Oh boy... I REALLY got that wrong! I thank you gents for the correction. Still, it was just a far fetched idea...

Greg
 
By the way, while I'm on, does anyone have a Stag V8 gasket (used!) they have laying around they wouldn't mind sending me? I'd send it back of course.

Greg
 
<blockquote><font size="1" face="Verdana, Arial">quote:</font><hr>Originally posted by Mark Beiser:
Why do people say the Stag engine is basicly 2 TR7 engines mated together, or that it uses TR7 anything?

The Stag existed before the TR7. If anything, parts of its engine would be compaired to a Triumph Dolomite engine, wich is what the TR7 engine is a development from.<hr></blockquote>

It is sort of like people saying the TR3 engine is a tractor engine, which of course it is not and never was
nonod.gif
. It was however made under contract in the Ferguson tractor engine foundry as were other Triumph blocks because they were neighbors, but the Ferguson Tractor engine was a very different low RPM flathead, the TR3 an overhead valve high RPM design, altogether different engines.
Same with the TR7 and Stag. Actually the 2 liter 4 cylinder predates the Stag because it was built for Saab under contract to Triumph for Saab to install in the Saab 88 and the Triumph installed it in the Triumph Dolomite. The money from Saab helped keep Triumph alive financially. The design between the Stag and Saab/TR7 engine is based on the same layout and design, some parts are interchangable like those in the cylinder head, but major castings and pressed parts are not. The TR7 head and timing chain cover are both shorter, but the basic top and bottom castings of the block are very close in measurements. Had the Stag V8 been two TR7 engines cloned together, the Stag V8 would be 4 liters. So the TR7 has a different stroke too.

cheers.gif
 
Back
Top