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I am going to build a 1071 engine with SA crank,
Posted: Sat Mar 28, 2015 2:47 pm
by goff
OK as title says, I have a engine 1275 block from a L reg Morris/Austin1300, a SA crank from Rich (Guru ) a 12G940 cylinder head from a 1300GT same as late cooper S, no pistons as yet, this engine will just be for a road car ,going to polish the head but not going mad just polish same time have unleaded seats fitted, I know there are a few of you guys who have this engine running in your cars ,me being old fashioned i was thinking of fitting the old BL 731 cam ,Question as anybody fitted the a 731 cam or one from another maker with that profile and how do you rate it
Thanks
Goff
Re: I am going to build a 1071 engine with SA crank,
Posted: Sat Mar 28, 2015 2:57 pm
by Smiffy
Had one in a 1380, back in the eighties and despite whats written. I thought it was brilliant.
Re: I am going to build a 1071 engine with SA crank,
Posted: Sat Mar 28, 2015 3:46 pm
by carbon
Goff,
I've a long term project along similar lines. Are you planning to get a set of 6 inch conrods or just slice 1/4 inch off the block?
If you're looking at 731 profile cams then one of AC Dodd's profiles is the RS+ and has very similar timing to 731 but about 20% extra lift so I reckon you could use this with standard rockers and get a decent torque spread.
Re: I am going to build a 1071 engine with SA crank,
Posted: Sat Mar 28, 2015 7:08 pm
by rich@minispares.com
I must say that my gtm is a beautiful engine with its minispares evo2 cam
its a 'big bore' 1071 in that its bored to 73.5, but there is no lumpiness, no dropping of cam, no issues.
ive no idea what it revs to, the rev counter stops at 7000, but id guess it will take 7500 no issue
its like a little motorbike engine, it just buzzes away like a sowing machine
Re: I am going to build a 1071 engine with SA crank,
Posted: Sat Mar 28, 2015 7:11 pm
by goff
carbon wrote:Goff,
I've a long term project along similar lines. Are you planning to get a set of 6 inch conrods or just slice 1/4 inch off the block?
If you're looking at 731 profile cams then one of AC Dodd's profiles is the RS+ and has very similar timing to 731 but about 20% extra lift so I reckon you could use this with standard rockers and get a decent torque spread.
Carbon
slice lump of the block, already sorted some conrods from spoon.45 ,forgot to say i will be using twin 11/2 SU
Goff
Re: I am going to build a 1071 engine with SA crank,
Posted: Sat Mar 28, 2015 7:14 pm
by goff
rich@minispares.com wrote:I must say that my gtm is a beautiful engine with its minispares evo2 cam
its a 'big bore' 1071 in that its bored to 73.5, but there is no lumpiness, no dropping of cam, no issues.
ive no idea what it revs to, the rev counter stops at 7000, but id guess it will take 7500 no issue
its like a little motorbike engine, it just buzzes away like a sowing machine
Rich
Are you running twin 11/2 halves.
Goff
Re: I am going to build a 1071 engine with SA crank,
Posted: Sun Mar 29, 2015 2:31 pm
by abri
I'd also be keen to hear what people think of the 731 camshaft since I have a NOS one and my motor is in bits getting rebuilt at the moment.
Re: I am going to build a 1071 engine with SA crank,
Posted: Sun Mar 29, 2015 4:45 pm
by rich@minispares.com
goff wrote:rich@minispares.com wrote:I must say that my gtm is a beautiful engine with its minispares evo2 cam
its a 'big bore' 1071 in that its bored to 73.5, but there is no lumpiness, no dropping of cam, no issues.
ive no idea what it revs to, the rev counter stops at 7000, but id guess it will take 7500 no issue
its like a little motorbike engine, it just buzzes away like a sowing machine
Rich
Are you running twin 11/2 halves.
Goff
in the gtm I use twin 1 1/4's - I think these are the carbs to use on a mild road going 1071.
my 1071 road car is a beast as its on twin h4's and has a 649 - the carb stand off is terrible, it spoils it really, but I was young and stupid when I built it - next time its in bits im going to detune it a bit - I will probably put an SW10 (I think it is) into it
it was alright in the days when you could keep it screaming, but it was dead below about 3500 rpm - it would just cough and splutter, but as long as you kept it howling it was pretty good - im too old for all that now
Re: I am going to build a 1071 engine with SA crank,
Posted: Mon Mar 30, 2015 10:56 am
by AndyB72
I can vouch for the 1071 in Richs GTM. After a passenger ride in it at Blyton last year I decided to go the same route for my GTM, a cracking engine!
I've also used the MiniSpares EVO cam in the last three small bore 998 and 1100 road engines I've put together and its a cracking cam.
Steve Foster is building my SA1070 +60 bore engine at the moment and I had intended using a SW10 to really make it rev and in a lame effort to try and beat Rich. Steve was concerned about my 'teenaged' choice of cam and after speaking to Swiftune they recommended the SW8 for a road engine with a bit more top end for the odd track day.