Dolomite sprint

silverseven · Postby **silverseven** » 02 May 2010 02:14

<blockquote id="quote">quote:<hr height="1" noshade id="quote">Originally posted by V8Wedgehead

I hate to say it but when you get done with all the work and expenses for the conversion....and this is thru experience the better way to go is converting your TR7 to TR8 specifications. You dont need as much as you think.........
<hr height="1" noshade id="quote"></blockquote id="quote">

I used to also be the one's who dreamed of either modding out my 4 pot or contemplating a sprint swap just to be different, but alas ........
I miss the kick in the pants feel and sound of a V[8]!

so for references sake , how much would a turn key TR7V8 conversion cost???

Ron.

Beans · Postby **Beans** » 02 May 2010 08:47

<blockquote id="quote">quote:<hr height="1" noshade id="quote">Originally posted by Spectatohead

Now if you were really crazy you could do the Stag V8 in a wedge. ...<hr height="1" noshade id="quote"></blockquote id="quote">
Still dreaming of a Stag Sprint engine [:I]
Triumph actually built two of these.
One blow up on the test bed, the whereabouts of the other are unknown ...

<center>

1980 TR7 DHC (my first car, currently being restored)
1981 TR7 FHC Sprint (better known as 't Kreng)
[url="http://www.tr7beans.blogspot.com/"]My Weblog[/url]</center>

reychris · Postby **reychris** » 02 May 2010 10:01

We used to have a highly tuned Sprint engine in the Dolomite that I help Rally. It was 200+ BHP. Radical cam, twin 48's a gas flowed head and most importantly a very strong bottom end. We made a thick steel ladder bracket between the sump and block and had the main caps machined to take supporting blocks between them and the bracket. Despite all the abuse thrown at it it never went bang. From the navigators seat I would often see it go up to 8k.
The only bad thing about it was a bad flat spot at 3k ish and being greedy we wanted more power so realising that there was no more to come from that engine without spending a fortune on it we put a tuned 3.5 Rover in it.
First event with that it went bang after stage three...[:(!]

If I ever win the lottery I'm going to build a Stag Sprint engine!

Beans · Postby **Beans** » 02 May 2010 10:08

<blockquote id="quote">quote:<hr height="1" noshade id="quote">Originally posted by reychris

... a highly tuned Sprint engine ... a very strong bottom end ... <hr height="1" noshade id="quote"></blockquote id="quote">
One of my plans for the future.
Thinking of a way to get around the flatspot @ 3000 rpm ...

<center>

1980 TR7 DHC (my first car, currently being restored)
1981 TR7 FHC Sprint (better known as 't Kreng)
[url="http://www.tr7beans.blogspot.com/"]My Weblog[/url]</center>

Bobbieslandy · Postby **Bobbieslandy** » 02 May 2010 22:26

<blockquote id="quote">quote:<hr height="1" noshade id="quote">Thinking of a way to get around the flatspot @ 3000 rpm ...<hr height="1" noshade id="quote"></blockquote id="quote">

Is this inherent of sprint engines? i know the needles can be filed at certain points to give more fuel at particular RPMs, that's assuming it's fuelling related of course!

For having fun i prefer revvy engines, i think this is the reason i went for the sprint over the V8.

nick · Postby **nick** » 02 May 2010 23:35

<blockquote id="quote">quote:<hr height="1" noshade id="quote">The reason for my conversion to sprint power was its rarety really, don't get me wrong, there's nothing better sounding than a V8 but i like something a bit more different, something to shut up the know it all when he asks if it's still got the standard 2 litre or have i just stuck a V8 in it. To be honest, looking back at the amount of money i've piled into this car i think i'd of bought one of the many Lexus LS400s on ebay for Â£700 and gone about shoving that in instead. Hindsight is a wonderful thing!<hr height="1" noshade id="quote"></blockquote id="quote">

I agree with Rob. The idea of a Sprint conversion is asthetically appealing. All that HP with only 4 cylinders and purely Triumph.
Looking at Rimmer's catalog I can't quite figure out what they are offering for this conversion. I suppose I should just call them and ask.

nick
'79 TR7

Jolyon39 · Postby **Jolyon39** » 02 May 2010 23:48

An EFI conversion may help you cure that flat spot at 3000rpm.

MMMmmm an EFI sprint motor, what a nice thought.

Jolyon

Bobbieslandy · Postby **Bobbieslandy** » 03 May 2010 00:00

The comment about the lexus was me just being bitter, I'd had a tough time in the garage and was in one of those "moods"!

If i'd of seriously thought it was not going to be worth it i would of stopped the conversion (rebuild) long ago. I also like the fact they rallied that engine, i'll be thinking that as i tear around the country lanes[8D]

I also like the fact that ford had a 16v engine in the 70s so this is my way of sticking a finger up at those with the over priced BDA powered Mk1 escorts!

<blockquote id="quote">quote:<hr height="1" noshade id="quote">Still dreaming of a Stag Sprint engine
Triumph actually built two of these.
One blow up on the test bed, the whereabouts of the other are unknown ...
<hr height="1" noshade id="quote"></blockquote id="quote">

The Ford Scorpio 2.9 cosworth had the extra valves treatment, legend has it it was detuned from a reliable 300bhp down to 200bhp. The mind boggles at the sprint V8! how hard can it be? haha

Beans · Postby **Beans** » 03 May 2010 08:37

<blockquote id="quote">quote:<hr height="1" noshade id="quote">Originally posted by Bobbieslandy

... Is this inherent of sprint engines? ... <hr height="1" noshade id="quote"></blockquote id="quote">
Not as far as I know.
But it is inherent of slightly radical camshafts [B)]

<blockquote id="quote">quote:<hr height="1" noshade id="quote">Originally posted by Jolyon39

An EFI conversion may help you cure that flat spot at 3000rpm.
<hr height="1" noshade id="quote"></blockquote id="quote">
That in combination with fully programmable ignition [8D]

<center>

1980 TR7 DHC (my first car, currently being restored)
1981 TR7 FHC Sprint (better known as 't Kreng)
[url="http://www.tr7beans.blogspot.com/"]My Weblog[/url]</center>

reychris · Postby **reychris** » 03 May 2010 10:15

Beans is spot on. The flat spot was the cam, we also thought the only way round this was fuel injection and a mapped ignition system. That was a bit much for our old fashioned brains so went for a V8 instead. In hindsight I'm not sure that was the best decision we ever made.

nick · Postby **nick** » 03 May 2010 16:31

Does anyone have the pictures that go with this article? The links to the pics are no longer working.

http://www.triumphtr7.co.uk/sprint_conv.html

nick
'79 TR7

Beans · Postby **Beans** » 03 May 2010 17:03

mmm ... Mr. Stokes'car [:)]
Pictures show up on my computer though ...

<center>

1980 TR7 DHC (my first car, currently being restored)
1981 TR7 FHC Sprint (better known as 't Kreng)
[url="http://www.tr7beans.blogspot.com/"]My Weblog[/url]</center>

kstrutt1 · Postby **kstrutt1** » 03 May 2010 20:45

You can look at Rimmer bos web site and get an idea of the cost of parts but a full kit is around Â£1500, If you get a reasonable secondhand engine and just de-coke and replace the cam (always the first thing to go) that will be another Â£500 you will also need the SD1 bell houng and clutch parts at around another Â£250, so you are looking at around Â£2250 in parts, labour to put it together would be at least Â£500 so the best part of 3 grand.

On the other hand I made my own X member, radiator supports and exhaust, already had uprated brakes and suspension, used the original TR7 radiator (only difference is the size of pipe outlets) and did all the work myself so the total cost was around Â£700.(but it took 3 months of spare time).

nick · Postby **nick** » 03 May 2010 21:39

<blockquote id="quote">quote:<hr height="1" noshade id="quote">mmm ... Mr. Stokes'car
Pictures show up on my computer though ...
<hr height="1" noshade id="quote"></blockquote id="quote">

Switched from Mozilla to IE and the pictures appeared. Thanks. Technology run amuck.

nick
'79 TR7

jeffremj · Postby **jeffremj** » 08 May 2010 23:12

<blockquote id="quote">quote:<hr height="1" noshade id="quote">
The inlet and exhaust manifolds are different, the carb linkages and needles are different, you need the cast alloy end plate, the chain is duplex on the sprint engine so you'll need the relevant sprockets, tensioner and runners (although i think the tensioner and runners may be the same, you'll need to change them if they're worn), the pistons are different (and very, very expensive) and the sprint crank is also different, it's cross drilled to cope with the stresses the power hike will put on it. On the same note, your original one will have to be mint or the bottom end won't last very long at all! the sprint engine in TR7 form can potentially put out 150bhp, 50% increase on the standard 8V so there's the usual brake upgrades, suspension upgrades to fork out for unless you've already done that.

I think i've listed all the differences, i'm sure someone will add to them!<hr height="1" noshade id="quote"></blockquote id="quote">I never found it a problem and consider it a relatively simple mod. I used the complete TR7 bottom end and had zero problems with it - revving to 7000rpm. All I did for the pistons was to get the appropriate valve cutouts made. Here is my simple ABC on how to do it:

http://www.btinternet.com/~triumph/geocities/16vconv.htm

Anonymous

Dolomite sprint

Who is online