Hello.
Searching for answers is the standard camshaft in a 1300gt is a good cam to leave alone or is there a better cam for improving performance without effecting driveability. Standard 1300gt is 70bhp ish.
Austin 1300gt cam
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CooperTune
- 1275 Cooper S
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Re: Austin 1300gt cam
I have no idea what an Austin 1300GT cam is. I have used several MG Metro cams with good effect. Steve (CTR)
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W1NG3D
- 998 Cooper
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Re: Austin 1300gt cam
1300GT units were good engines from factory but, if I'm not mistaken, the cam is nothing special.
That said, are you certain that what you have is the standard cam, or indeed that it's an original 1300GT engine? If so I'd be surprised if your engine hasn't been rebuilt at some point in its life, as even the youngest 1300GT powerplants are going to be 50 years old now given that model went out of production in '74.
In any case it sounds like what you're looking for is a mild but slightly uprated cam for road use, which could net you some performance gains alongside a decent cylinder head over a standard setup. There's a decent selection of proven cam profiles on the market that're suitable for this application, including (but not limited to) Swiftune's SW5, Minispares' EVO1, ACDodd's RS and RT, or even the MG Metro profile which is often touted as the best factory road cam produced for the A-series.
You could of course fit higher lift rockers (1.4 or 1.5 ratio) to increase valve lift without upgrading your cam at all, but this has its drawbacks on a road engine as it will increase load and wear on the valvetrain, but will unlock a bit more "top-end" power with some sacrifice to low-down grunt - depending on the cam, this could take your car beyond the realms of nice everyday drivability, basically it is a compromise.
All that said, it's worth bearing in mind that swapping out one single component won't automatically give you optimal results with an engine. A suitable camshaft should go hand-in-hand with a properly set up cylinder head as mentioned earlier, but there are a whole host of other factors at play with engines such as compression ratio, carburation & exhaust setup, ignition timing and advance curves, gearing & final drive ratio, to name but a few. i.e., you might upgrade your camshaft only to realise that the head is restricting flow massively, your carb(s) are worn or undersized, or your ignition system is sub-optimal.
This all really depends on how you drive your car as well. If it's for pottering around town, you might want a very different setup to a "weekend warrior", or a motorway cruiser.
I appreciate that this is a bit of a long-winded answer, but there's a lot to think about before jumping into a camshaft upgrade which is fairly labour intensive, especially considering you might find there are quicker and cheaper gains to be had elsewhere before you start getting into the innards of the bottom end. Even just getting your current setup properly tuned and dialed in by an expert is likely to be a better starting point, then if further performance is sought, you can then look into upgrading from there. (Feel free to ignore me if you've already done that, of course!)
That said, are you certain that what you have is the standard cam, or indeed that it's an original 1300GT engine? If so I'd be surprised if your engine hasn't been rebuilt at some point in its life, as even the youngest 1300GT powerplants are going to be 50 years old now given that model went out of production in '74.
In any case it sounds like what you're looking for is a mild but slightly uprated cam for road use, which could net you some performance gains alongside a decent cylinder head over a standard setup. There's a decent selection of proven cam profiles on the market that're suitable for this application, including (but not limited to) Swiftune's SW5, Minispares' EVO1, ACDodd's RS and RT, or even the MG Metro profile which is often touted as the best factory road cam produced for the A-series.
You could of course fit higher lift rockers (1.4 or 1.5 ratio) to increase valve lift without upgrading your cam at all, but this has its drawbacks on a road engine as it will increase load and wear on the valvetrain, but will unlock a bit more "top-end" power with some sacrifice to low-down grunt - depending on the cam, this could take your car beyond the realms of nice everyday drivability, basically it is a compromise.
All that said, it's worth bearing in mind that swapping out one single component won't automatically give you optimal results with an engine. A suitable camshaft should go hand-in-hand with a properly set up cylinder head as mentioned earlier, but there are a whole host of other factors at play with engines such as compression ratio, carburation & exhaust setup, ignition timing and advance curves, gearing & final drive ratio, to name but a few. i.e., you might upgrade your camshaft only to realise that the head is restricting flow massively, your carb(s) are worn or undersized, or your ignition system is sub-optimal.
This all really depends on how you drive your car as well. If it's for pottering around town, you might want a very different setup to a "weekend warrior", or a motorway cruiser.
I appreciate that this is a bit of a long-winded answer, but there's a lot to think about before jumping into a camshaft upgrade which is fairly labour intensive, especially considering you might find there are quicker and cheaper gains to be had elsewhere before you start getting into the innards of the bottom end. Even just getting your current setup properly tuned and dialed in by an expert is likely to be a better starting point, then if further performance is sought, you can then look into upgrading from there. (Feel free to ignore me if you've already done that, of course!)
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Robbie224
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Re: Austin 1300gt cam
Hello thanks for a helpful reply.
It's definitely a 1300gt ADO16 engine including gearbox.
It was rebuilt 4 years ago before I owned mini by some called Roger Hill. far as I'm aware rebuilt to a standard build. (H) high compression with standard gt dished pistons twin hs2 carbs on a large vavle doubled springed 12g940 ( 12g1805) head. 1300gt was rated at 70bhp . Its already rather rapid from 0 to 60 . I'm assuming that's with the standard cam. Don't know if it is 70hp but would like to get into the 80s. Hs2 carbs are probably 50 years old including linkage. I am getting new completely new hs2 carbs linkage set next year so I know there 100% good and a swift tune csi dizzy and LCB manifold. Probably will get a different cam next year maybe a ac Dodd one just for peace of mind or I'd always be thinking what if. What I want is a faster road car that can still be driven around town ect.
It's definitely a 1300gt ADO16 engine including gearbox.
It was rebuilt 4 years ago before I owned mini by some called Roger Hill. far as I'm aware rebuilt to a standard build. (H) high compression with standard gt dished pistons twin hs2 carbs on a large vavle doubled springed 12g940 ( 12g1805) head. 1300gt was rated at 70bhp . Its already rather rapid from 0 to 60 . I'm assuming that's with the standard cam. Don't know if it is 70hp but would like to get into the 80s. Hs2 carbs are probably 50 years old including linkage. I am getting new completely new hs2 carbs linkage set next year so I know there 100% good and a swift tune csi dizzy and LCB manifold. Probably will get a different cam next year maybe a ac Dodd one just for peace of mind or I'd always be thinking what if. What I want is a faster road car that can still be driven around town ect.
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Striped shirt
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Re: Austin 1300gt cam
Hello.
The 1300GT cam is no different to any other 1275 A-series engine, BMC 1300, 1275GT, Allegro, etc. They are just generic wide lobe, spider drive.
The 1300GT cam is no different to any other 1275 A-series engine, BMC 1300, 1275GT, Allegro, etc. They are just generic wide lobe, spider drive.
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W1NG3D
- 998 Cooper
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Re: Austin 1300gt cam
If it was rebuilt that recently I'd be very surprised if you have a completely stock cam in there, in any case it's incredibly unlikely to be the original one from the '70s, even if it's still a mild / standard-ish profile now. Perhaps you can get a detailed build spec by getting in touch with the builder? That would give you all the information you need to make a well informed decision about potential upgrades. Otherwise you may well find that you go to the trouble and expense of upgrading your cam, only to find that you've already got something decent in there once the engine's apart.Robbie224 wrote: ↑Fri Jan 12, 2024 2:48 pm Hello thanks for a helpful reply.
It's definitely a 1300gt ADO16 engine including gearbox.
It was rebuilt 4 years ago before I owned mini by some called Roger Hill. far as I'm aware rebuilt to a standard build. (H) high compression with standard gt dished pistons twin hs2 carbs on a large vavle doubled springed 12g940 ( 12g1805) head. 1300gt was rated at 70bhp . Its already rather rapid from 0 to 60 . I'm assuming that's with the standard cam. Don't know if it is 70hp but would like to get into the 80s. Hs2 carbs are probably 50 years old including linkage. I am getting new completely new hs2 carbs linkage set next year so I know there 100% good and a swift tune csi dizzy and LCB manifold. Probably will get a different cam next year maybe a ac Dodd one just for peace of mind or I'd always be thinking what if. What I want is a faster road car that can still be driven around town ect.
New linkages for your HS2s are all well and good, but if the carbs still have wear they'll be providing erratic and inconsistent fuelling, which is exacerbated on twin carb setups where balance between the pair is important. Also I'd note that twin 1.25" carbs aren't good for much more power than you're quoting, a single 1.75" (HIF44 being the popular choice) or a pair of 1.5" carbs (H4/HS4/HIF38) will provide much greater potential if the engine is capable of making use of it.
It's worth bearing in mind that while you're quoting a desire to increase top-end horsepower, the engine's torque curve is arguably the more important factor here as it's the low-end "grunt" that gives you usable performance on the road.