Tuning the slant 4

[Orophin]

I've given it some thought and I've decided to keep the TR7. Okay...I've also done some homework. I want to know what is worth tuning and what isn't, because i'm not rich [:(] but i'd like some extra power from the standard 105bhp, which is most probably less than that now. I've figured getting a stainless sports exaust with extraction manifold with K+N filters and new needles for the carbs. Anybody done this? Tell me what you've done with slant 4? Cheers!

[paul w]

For a start,fit electronic ignition,this gains only a
few horses when engines timed up,but you wont need to
bugger about with contact gap ever again.If you done
it once,you'll know what i mean!
A sport manifold and exhaust and needles/filter kit
will certainly unleash more power,but you will spend
around £250-300.And more importantly you will need
a big brake upgrade before any of the above exhaust
stuff.
I'd get the eleccy'ignition first - can't run 'for
ya can walk!!(esp.with out brakes)

See ya. Paul

[John Clancy]

An electronic fan makes a fair bit of difference as it removes that almighty fan housing and pulley mechanism. You should find the engine revs more freely once that is gone. You could even test it before committing by just removing it and going for a quick blast. The fan belt won't fit once it's off of course but for a short run the battery should survive.

After that there is a lot you can do to the 2 litre engine. It responds extremely well to a high lift cam but I'd probably only recommend doing that once the cylinder head has to come off for other reasons.

<center><b>[url="http://www.triumphtr7.com/documents/sales/codenamebullet.asp"]Buy the story of the Triumph TR7/8 on DVD here[/url]</b></center>

[Wayne S]

Hi Orophin,

Good news that your keeping the car. My car has a tuned slant 4, done initially by Grinnal. Grinnal were a company that specialised in tuning, bodykits and V8 conversions and you can read more about them elsewhere. My car had the full kit from Grinnal with oversized sills, flared arches, body coloured bumpers and front spoiler etc and Rover SD1 rear lights and Compomotive split rim alloys.
Rather than dropping in a V8 the owner at the time decided to have the standard engine tuned and carried out the following:

Gas flowed and ported cylinder head.
High lift cam (requires thicker shims than standard)
Gas flowed and ported inlet manifold.
Lightened and balanced crank and flywheel.
Removed the viscous fan and replaced with uprated 4 core radiator with 14" pacet fan.
Removed the air filter paraphanalia and replaced with deep K&Ns with internal ram pipes.
Tubular extractor manifold and large bore exhaust.
Richer BAL needles within the standard HS6 carbs.

At the height of its tune, the car gave a dyno print out of 133 BHP which is pretty much as much as you'll get out of the 8 valve head.

As John Clancy suggests, start first off by fitting electronic ignition. It not only releases some horses but just makes day to day maintenence much easier... its a case of fit, set up and forget.

Take off the air box and replace with K and N pancakes. Or bolt on a set of ram pipes/trumpets and cover with one of the ITG filters.

Getting rid of the viscous fan will gain you around 5 BHP in some cases and does let the car rev more easily. Fit a nice chunky pacet or kenlowe and you'll get increased cooling as well. You will also need a shorter fan belt to join the alternator to the front pulley.

The key really is to get the engine breathing properly so before doing anything else get a tubular manifold and sports system fitted, these do come up on eBay from broken cars from time to time if you are on a budget.

Once the engine is breathing properly then you can progress to other more drastic mods. Unfortunatley my engine broke after 120,000 miles of service this summer and due to it being my only car I had to drop an new engine in rather hurriedly. £300 bought me a full engine with 30K on the clock with head and carbs so in it went. Ive since fitted my high lift cam into the standard head on this engine and the improvement is not as striking as it was with the flowed head despite retaining all the other mods still, so its worth doing the two together. My advice would be to buy as good second hand head from eBay and have an engine shop do the neccessary on it for you, they can shim it correctly as well. Just for reference the tappet clearances are the same as for the standard cam. You can then do a direct swap if and when you need to remove the old head.

The other thing to consider is that all power modifications will put increasing strain on the bottom end of your engine. You must be confident in the strength of the engine before doing these mods OR build yourself a new engine with all the tuning accessories to swap over if your able.

A friend of mine is building a stage 2 engine with dellorto carbs at present. I still have the standard SUs (albeit with richer BAL grade metering needles) and find they deliver all I need them too, not certain of the benefits given by webers or dellys.

The way I have gone about mods or upgrades over the 3 years I have owned my car is to replace things as they fail with uprated or tuned components and it has been a gradual and on-going run of improvements as my budget has allowed. During the christmas break im uprating my springs all round to complete my suspension mods that I started when I first got the car.

<b>BUT</b>
I cant stress enough the importance of uprating the brakes. At the very least invest in the EBC grooved discs and greenstuff pads to fit the standard calipers and wheels.
I have these coupled with an uprated servo and braided hoses and they have made the brakes "satisfactorily safe" but there is still room for improvement.


Purple 2.0 Litre DHC Grinnal

[stricky]

Yep i agree with the above post...........

take your time and do things gradually.

I've got a pretty original low miles 2.0 litre car so wanted to keep it that way. I went for the S&S kit that has a gasflowed head, cam exhaust etc, also went for electric fan, SU needles etc. It has given me tremendous fun over the last few years but let me say it's no 'dragon slayer' as it only produces 120 -30 'ish bhp

But if you're concerned with cost i'm convinced a more economical route would be a 16v sprint engine transplant, but as mentioned above your first purchases should be suspension and brake uprades first [:D]

'81 TR7 DHC
'79 TR7 V8 FHC

[Beans]

<blockquote id="quote"><font size="1" face="Century Gothic, Verdana, Arial, Helvetica" id="quote">quote:<hr height="1" noshade id="quote"><i>Originally posted by John Clancy</i>

An electronic fan makes a fair bit of difference as it removes that almighty fan housing and pulley mechanism. You should find the engine revs more freely once that is gone. You could even test it before committing by just removing it and going for a quick blast. The fan belt won't fit once it's off of course but for a short run the battery should survive.<hr height="1" noshade id="quote"></font id="quote"></blockquote id="quote">
Has been debated before. First of all if you take the fan belt of, you'll also loose the alternator, now that's a part that robs a few BHP's (depending on what you've switched on of course).

In my car (DHC) I went the route the other way round. Car came with electronic fan and I replaced it with original one. Couldn't feel any noticable difference in engine pick up. If you want the engine to respond more quickly shave about 1,5 kg's of the flywheel. And it will still idle nicely.

<center>
<font color="blue"><i>1981 TR7 FHC Sprint (better known as 't Kreng)
1981 TR7 DHC (not very well known yet, but back on the road)
Also a 1980 TR7 DHC, 1980 TR7 DHC FI, 1981 TR7 FHC
http://tr7beans.blogspot.com/</i></font id="blue"></center>

[frankman]

Since you are from England, I would Dolomite an engine to envisage because they are cheap ... If you like something or ignition carburetor or flywheel do you have the right basis.

But a 16V is safe without tuning a large profit ... But I have never driven one .. but ask Beans - he has normal, 16V and V8 so he can tell

Hello from Switzerland

Frank

[Beans]

Sorry they are both not normal, as in slightly tuned [;)]

<center>
<font color="blue"><i>1981 TR7 FHC Sprint (better known as 't Kreng)
1981 TR7 DHC (not very well known yet, but back on the road)
Also a 1980 TR7 DHC, 1980 TR7 DHC FI, 1981 TR7 FHC
http://tr7beans.blogspot.com/</i></font id="blue"></center>

[Orophin]

Thank you ever so much for providing me with all this info. [:)] Very helpful.

Right...you have now greatly interested me in a sprint engine project. Tell me...is this easy or not? I had a look at the v8 project, and it looked like alot of work. Sprints are about 130bhp anyway, what needs to be done on this project? Thank you for your input so far!

[bmcecosse]

Main problem is that the Sprint exhaust manifold doesn't fit in a TR7 - so you need a custom one. Otherwise - reasonably straightforward with some water hose fiddling. If your own engine is in good working order - ask yourself if the change is really worth it for extra 20 bhp!

[paul w]

It never ends with just an engine upgrade.Like i said before
the first thing on your list should be brakes.Then put the
lump in.Then you'll need to uprate the cooling - better rad,
bigger electronic fan and controls.The exhaust manifold will,
as bmc' says need to be changed for a custom one.
You sometimes see full engines and related parts on Fleabay,
which can keep costs down.
In the book 'How to improve Triumph TR7 TR7v8 TR8'is a lot
of info on this subject. ISBN 978-1-84584-045-7

See ya. Paul

[Hasbeen]

Orophin, & anyone interested, you often don't get all that much from
even quite large increases in power from any car, although I think
the 7, & especially the US 7 do respond well.

In 1963 & 4 I raced a Morgan +4, [Triumph TR3A engine], starting with
a new Morgan in late 62. To put things in perspective, the Morgan
new, in Oz, cost about 2 years of the motor mechanic award wage, &
I spent about half that much again, setting it up for racing. I then
spent at least that much, each year, in engine, & suspension
developement.

The power figures are at 4600 RPM, at the wheels, rather than peak
power, as thats where I expected to spend most time, while racing,
so thats where we tuned the engine. A flash reading suggested about
120 BHP at the clutch, at 5500 RPM, when we had 79 sustaned at 4600.

Probably half the reduction in lap times were from suspension
upgrades, rather than engine improvements.

The biggest disappiontment was in top speed, probably because the
thing ran out of breath around 6000 RPM. With 79 BHP the car
recorded 124.36 MPH through the flying quarter on Conrod straight
Bathurst in 1963, but with 115 BHP, in 1964, it did only 124.63 MPH.
A 45% increase in horse power had given me just 0.27 MPH.

The following is my lap times, at some circuits, with higher power outputs.

Power..............79BHP...........92BHP............115BHP

Bathurst............3.20.9.................................3.10.2
........................124.36MPH..........................124.63MPH

Warwick Farm...2.03.8..........1.59.6.............1.58.1

Oran Park..........1.0.9..................................0.58.5

Catilina..............1.12.2..........1.11.2..............1.10.5

So, as you can see, horse power upgrades don't necessarily make the
car much quicker.

Hasbeen

[frankman]

..Hi Orophin..

It is true whether you get the 8V tuned or Dolomite 16V or even install a V8 the brakes are, of course, always a weak point but that they are also without tuning, and the question is always how someone drives? We have a lot of mountains and hills so it is almost inevitable, with faster driving style the brakes, and to the suspension to improve.

As I said personally, I find it better with the correct base to start the engine is a 16V to install (this is only the Oilpan and the Engine plate to change only minors - and with the manifold was are you on about, and the 135PS is the basis -- 8V when you have already been invested there and are at the end ..

I am convinced that at the end you have less invested, and a lot more fun - you like such a 16V .. The 8V Since then did as a reserve .. But as I said brakes and suspension is always a topic the car is already about 30 years old ..

-- Oh yes, by the way this option is/was original

Hello from Switzerland

Frank