Jump to content

Engine Upgrades


Recommended Posts

Hi Guys i am running a 1500 with Twin Su's in a herald and would like some advise on how to improve performance with small upgrades rather than the obvious engine out and re-bore sort of things. I want to use the car daily from now until October and would just like to tweek a bit more power out of the old girl without breaking the bank



Link to comment
Share on other sites

If you do not want to change things like camshaft/head, then you are left with the basics.
Swap to a 4 branch extraxctor manifold plus better exhaust (canleys do a very nice system, uses a vitesse exhaust box that seems to work very well)
Make sure the carbs are in good condition.
Fit Free-flowing air filter, ideally with a cold air supply. Not as easy as it sounds :-/
Check distributor is working correctly
Get it properly tuned and the needles to match the new filters and exhaust. (The last bit is the most important.)

None of the above are particularly cheap, especially the exhaust system.
The best "cheap" exhaust would be to use the spitfire 1500 cast manifold and downpipe, but there can be reoccurring issues with downpipe gaskets.

Plus make sure the suspension is properly set up with the correct camber/castor/alignment. That could make a bigger different to overall speed than the engine.
Dump all excess baggage from the car.

Link to comment
Share on other sites

Hmm, surprised there hasn't been loads of replies to this one.
To be honet, having messed about with these cars for years, the thing that I think makes the most difference is getting the std setup tuned accurately. That means a rolling road setup.

If you want to go further a higher CR head and camshaft plus exhaust would be the next stage, not really that expensive to do and can be done with the engine in (bit of faff but do-able)

Link to comment
Share on other sites

I think you've said it all Clive....

I suppose the next step could also include matching the inlet manifold to the head ports, and smoothing the short side radius of the head's inlet ports, plus some 3 angle valve seats.  Not particularly expensive, but does take some time and effort, and of course, means you have to take the head off to do it.

Beyond this, it starts getting expensive and you then enter the realm of diminishing returns for your outlay.  Doing what Clive says above, with perhaps some home port matching, and moderate and careful SSR smoothing will give a worthwhile improvement for little outlay.

Link to comment
Share on other sites


This topic is now archived and is closed to further replies.

  • Create New...