1289 or 1397?

potentz

Member
Hi guys,thank you all so much for your advice.!!!

i think i will be very happy with a free revving motor around 90 hp.
To keep cost down as i already have a new 1289 piston and liner kit,i have decided to go with the 1289 option with lightened flywheel'd/d weber, mild cam ,prescribed headwork and extractors.

i would appreciate advice on porting /polishing and comp ratio work(to achieve 10:1 cr if required) on the head
and cam specs .

Just to throw the proverbial spanner in the works,would the r9/r11 head work wth the 1289 and where would i source one from, approx cost?

cheers brian
 

alan moore

1000+ Posts
I like Alan Moore's mods he mentioned above but instead of doing it to a 1289, do it to the 1397. With those humble mods the difference in being a revvy motor will be negligible and I think the additional cc's will push the horse power up a little more. Regards
Frans

I do agree that 1397 is a better way to go. The lack of "revvieness" that people talk about compared to the 1289 probably has more to do with cam specs than the dimensions of the engine. I am quite sure that a 1397 can be made to sing to 7000 without a lot of work.

The choice originally was 1108 or 1289cc, you always will go with capacity in these small engines.

Have a look at the Tighe Cams in Brisbane website at Ford 1600 grinds. I would recommend the 102 or 113 for your purposes. Both a reasonable upgrade on standard without getting too silly with lift or overlap. The 113 will give a small lope at idle with a downdraft. You will require some better valve springs to cope with either. The valve guides may also need to be taken down a little to stop the valve spring retainer hitting the top of the guide. You must also get the cam followers ground at the same time as changing the cam.
 
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4cvg

1000+ Posts
I do agree that 1397 is a better way to go. The lack of "revvieness" that people talk about compared to the 1289 probably has more to do with cam specs than the dimensions of the engine. I am quite sure that a 1397 can be made to sing to 7000 without a lot of work.
<snip>
QUOTE]

a 1397 r5 alpine/gordini certainly will
peter
 

potentz

Member
1397!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
 

c.lees

New member
A long time in the making was it?

The real question for me is 807 or K4M? I also have a 1397 and two R10S engines.
 

Johan

New member
I like Alan Moore's mods he mentioned above but instead of doing it to a 1289, do it to the 1397. With those humble mods the difference in being a revvy motor will be negligible and I think the additional cc's will push the horse power up a little more. If you use the head out of a R9 or R11 the effects will be even greater because of the improved port design on those heads.
If you are willing to buy a set of Mazda pistons (I have the part no.) it will cost you only the machining of the small ends and a rebore to 78mm and then you have 1480cc with a standard 1397 head gasket. Then you have the same revvy motor with even more horses. You can keep the downdraught but just jet it accordingly. All above won't bust the bank either.
If you then decide to go fullhouse the bottom end will be there already and it will only mean head work.
Regards
Frans

Listen to Frans
 

rubyalpine

New member
If you are going to go downdraught (which is fine), then I highly recommend a more tunable Weber such as the 36DCD7 or the 28/36DCD as used on early (non-crossflow) Cortina GTs. With these you can fit larger choke tubes and they can be more easily tuned to suit the rest of the mods. They can be set up to flow a lot more air/fuel than the 32DIR type with the fixed size choke tubes.

Henry
 

schlitzaugen

1000+ Posts
Yeah, good luck finding a DCD.

The best downdraught (within reason, and still available new) is perhaps the 32/36 DGV. Even better you could pick one of these for a song if you raid your local pick a part. Even better, the literature/net info about tuning these is endless (by application).
 

geckoeng

1000+ Posts
You guys were really let down by what you had available here in Australia. My Renault 16TS powered Space Frame off-road car in S. Africa ran first a 38DGAS and then a 40DFAF off a Ford V6, and the 1605 motor was putting out 125 hp at the flywheel with fantastic torque. From a hand made plenum manifold with big straight runners to the valves.

The carb was a simultaneous, and I modified it to a progressive. After 1/3 throttle it opened full very rapidly. The 16TS ate all the air it could give the motor. Absolutely fantastic mid range torque and throttle response. A 1480 Siera with well ported head and slightly bigger valves would use this very well.

The only extra it needed was a hot water block between the carb and manifold to stop icing on early morning starts.

Ray
 

schlitzaugen

1000+ Posts
The 38/38DGAS is available here (again at wreckers) for not much. I think it was used on some older Holdens? Fords? I can't tell the difference, but I saw it personally on the cars. Yep, synchro carb, a bit too thirsty for daily drivers. A stock 807 out of a 17G will give you 120 at the flywheel. FI, of course.
 

geckoeng

1000+ Posts
schlitz....

We were talking performance here, if you want to do F1 save the green planet fuel saving, I have a Renaunt 10 Solex available....

Ray
 
So, you went the 1397cc route by the looks?
I missed this thread first time around.

One point I was going to make that no one mentioned or may even know about. In my shuffling of parts and building the engine sitting in my R10S replica is that the 1251cc R12 block will not take the 1289 liners without a modification to the liner seats. I tried it as I am using an R10S block with the original liners, taken out to accomodate a very good set of 1251cc pistons I had. The larger 73mm liners wouldn't go.

I was shocuked actually as the R10s block is identical to the 1289 block in every other way. it does differ from the standard 1108cc block too in a few areas.

My final engine specs are, 10S block, 1251cc pistons with a 1289cc crank so I have ended up with 1251cc.

Cam is a mild grind, I haven't got specs handy but it will be a fun drive with the 10S inlet manifold, some port work as well.
A set of extractors at a later stage will complete the build in the end.
Also has an original R10S carbie and 1.4 flywheel and 10S bellhousing.


Here's hoping it will be a sweet motor. (when I finally finish the car)
 

Kram

New member
Potentz, you may like to know that Adelaide has one of the World's finest head porters, not an exaggeration. Tony Knight Engines, in Somerton Park.

You can Google some of his stuff.
 

Berridale

Member
As said somewhere the R16 carby/10S manifold.
I had a R8 head with the nice ports /small combustion chambers and used a 1289 bottom end.
Waggot had a excellent cam , sonic extractors, light flywheel.
Very high compression ratio with that combo.
It went like a cut cat and i remember seeing the needle disappear on the right hand side.
No tacho but for sure 7,000 plus.
I ran that Renault R8 car for a few years , reliable.
Towed a bike and trailer to mount Gambier races.
 

geckoeng

1000+ Posts
Nice Brian,
We have talked many a time on the phone, and for what you have built you should be proud.
I have always believed that 270 to 285 degree cams work the best on the street, and a very good 4 into 1 exhaust manifold with long primaries is the way to get the Sierra working. You cant go above 10.5 CR because of our fuel. I know you have a big port R9 head but I think they all run out of torque at 6800 t0 7000 RPM. so rev limit is set at 6800 and the next gear you are well in the torque range to work well specially with the big box. I like a bit more flywheel than your, but that is personal. Your R8 has come from extended development.
It goes well so drive it and have fun.

Ray
 

bowie

1000+ Posts
you are stealing my dreams :p

That looks excellent, and that manifold is beautiful! Double congrats on getting the flywheel so even.
 
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