1289 or 1397?

Frans

Member
1000+ Posts
I have some issues with Potentz!!;);). He is so withdrawn. Or maybe I am the braggart. Maybe this will bring a lot of responses positive and negative but as you know there are a few APPS that you can download on your phone to check acceleration etc. How accurate? I don't know but it won't be far out. This car does a 1/4 mile in well under 16 seconds. Correct me if I'm wrong, Potentz, and you don't need to blush, you've done a very good job!

Torque will be good because of the exhaust. Calculated extraction allows you to use lumpier cams that becomes effective at lower rpm. A heavier fly-wheel will only help you to not stall it at the traffic lights. A heavy fly-wheel will not help you to attack an uphill with better end speed. That momentum of the fly-wheel has lost its effect within 50 meters of starting the hill.

My old saying, a motorbike has no flywheel and is fast and a F1 car has no flywheel and is fast, so why have a flywheel?

Regards, Frans.
 

bowie

Member
1000+ Posts
Good on ya! Must be great to have it at this finished state :)

More photos to brag please :)
 

dauphproto

Member
Great thread. I would always say go for the 77mm stroke motor as a basis, it is so much stronger than the 72mm and according to the laws of physics more fuel efficient. The lightest I have managed to get a std. flywheel is 3.5kg and this was used on the 8G with a R5 Gr.2 clutch giving around 6.5kg total, but when used with an AP racing alloy clutch the combo at 5kg proved to be too light to be practical with a long first gear. I took another flywheel down to just under 5kg and the combo is 6.5kg and works perfect. It is quite incredible how much difference 1.5kg can make, so always remember to factor in the clutch assembly on Flywheels as they can be very light or very heavy according to type.
 
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potentz

Member
Just a few details i disovered when i fitted the r5 turbo rocker shaft assembly to my r9cyl head. The reason i opted for this setup is because the r5 setup has a pedastal support on the ends of the shaft, so the shaft is more rigid under stress.
However, its important to note that the r5 rockers have differnt oil exit holes drilled in the rockers themselves. Be ause ther5 turbo runs valve stem seals, the rockers are designed to spray oil onto the seals.
So the solution is to fit your 1.4 or 1289 rockers to the r5 turbo shaft and bobs your uncle ,you wont have a smokey engine on start up.
Also check the holes are the samesize on the rocker shaft .i think i had to open them up a tad.
Just a bit of stuff i found out. It is worth doing the mod as you end up with a much more stable valve train. Cheers potentz
 

Bustamif

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
Hey Frans, what is the part number for those 1480cc Mazda pistons. And Potentz, who supplied the cam, titanium pushrods
titanium valve spring retainers and formula ford valve springs.
 

potentz

Member
BUSTA, the cam is one i bought off richard man a while ago for 20 bucks.it was a fresh grind unused that was surplus to his needs.if i recall correctly he did notknow the origin at the time.i did however measure it my self and will have to dig out the specs from my crappy filing system.will check tomorrow. The pushrods were made using oem ends fitted to titanium rods bought off ebay. The valve spring retainers come from Ruanova in spain.He also supplies titanium pushrods.the valve springs from Kelford Cams NZ
 
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Bustamif

Member
Great work Potentz, you have inspired me to do something with the spare 1.4 motor for my Alconi. It is a stock motor in bits, ready for a rebuild. I am planning to update the existing 1.4 in the car, a nice little motor with a few miles on it that I swapped for a case of beer.
Did you upgrade the conrods ? any changes to the standard oil pump ?
 

Frans

Member
1000+ Posts
Hey Frans, what is the part number for those 1480cc Mazda pistons. And Potentz, who supplied the cam, titanium pushrods
titanium valve spring retainers and formula ford valve springs.
I have lost the piston info over the years or recently when I moved. I think it is one of the two pictured below. Rather do a comparison with a Renault stock piston and see if it will work. The dome is not as prominent as in the drawing but has a great compression ratio boost. I have added some photos for you of the Titanium pushrod manufacturing process. The mushroom ends are turned out from stock pushrods and pressed into a pre-drilled Titanium rod. (solid 6mm or 1/4") It is a bugger of a job to turn the heads because of the hardness and being so thin.

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Frans

Member
1000+ Posts
Great work Potentz, you have inspired me to do something with the spare 1.4 motor for my Alconi. It is a stock motor in bits, ready for a rebuild. I am planning to update the existing 1.4 in the car, a nice little motor with a few miles on it that I swapped for a case of beer.
Did you upgrade the conrods ? any changes to the standard oil pump ?
I saw an article about the bottom end of these motors. The guys with the R5 Turbos reckon that the stock bottom end is good for up to 200Kw and only needs mods for higher than that. How true it is, I don't know but I think for NA you do what you please.
Frans.
 

JohnW

Too many posts!
1000+ Posts
thanks ray and others. this is the exhuast system i made. the flywheel was marked out using a pair of deviders and drilled on my home pedestal drill and when taken for balancing,was much to the balancers" delight ,spot on.
Now ,i know some would be of the opinion that 4kg is too light for the flywheel, but this setup works for me.

the engine is very torquey and will readily pull from 50 kph in 4th gear.i have never experienced a lack of "flywheel effect" even on steep hills, amazing how little throttle is required at 100 kph in 4th gear.!!!!
Idle is very good and not lumpey .just a nice lope to indicate a cam upgrade . the motors propensity to rev has to be experienced to be believed and you have to be nice and quick through the gearbox. sounds like a high powered 4 cyl motorbike when the throttle is blipped on downchangers, so lots of fun.

So a big thank you to FRANS and RAY for their guidance and support and friendship over the years. Really made this whole experience worthwhile and very enjoyable.

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You could sell those exhaust systems........
 

jaahn

Member
1000+ Posts
Hi :)
Just a comment from my experience from long ago that might be helpful to a newbie starting a project.
We found with the 1100 motor that running a big lift cam and large degrees that the cam and lifters had a very short life. It was determined in conjunction with the cam grinder that the lifters were too small a diameter and the cams were going past the edge of the lifter. So we reamed out the block and put in larger diameter lifters, possibly from a Holden. The second thing was the standard Renault lifters were not radius ground as supplied and we always had them done from new or used for any cam which increased the reliability a lot.
Any comment from you current engine modifiers ! ;)
Jaahn
 

dauphproto

Member
The valvetrain is the weak link in the 1397cc crossflow engine and the followers are on the small side, recut cams always cause issues with geometry as some of the base circle is missing. In the end I went to a new steel cam and followers which solved the problem of huge valves, high lift 0.500" and 8000 rpm
Just a quick word on valve springs. If you have a good local race engine shop they should have a valve spring tester, it looks like a mini pillar drill, you put your chosen valve springs in it and set it to the installed length and read off the seat pressure (which in the above photo should be 67lbs at 32mm installed length) then you set the stroke of the machine to the valve lift (cam lift x rocker ratio ) and read off the nose pressure
As a general rule of thumb you do not want less than 40lbs of opening pressure and around 200lbs of nose pressure less causes float, more causes premature wear
Not sure about the FF springs above, FF do not rev and don't have mad lift, as you can see above, 12mm is the safe max lift you should use with these. Plenty valvespring sets around for hot Ford crossflow motors that will be more accomodating.
 

rubyalpine

New member
I got my cam and valve springs from Kelford Cams. I gave them the "production" Alconi specs and they said the closest match they could do was a [Ford] Broadspeed profile. It's quite mild, defiitely not lumpy.
 

Frans

Member
1000+ Posts
I bought myself a vice-operated one at a good price from the USA. It works very well because of the fine adjustment you get from the vice when it operates at maybe 1% of its capacity. These are the Matra engine specs in the photos.

This is the on-seat pressure with the valve length.
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This is the on-cam pressure.

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If you are happy with the results then complete your installation. If not, then either add a spacer or remove material from the base until it is good. Luckily the Renaults have 7mm valve stems which makes it lighter than most cars and with the Titanium pushrods, you save another few grams that need to change direction.

Regards. Frans.
 

potentz

Member
if i remember correctly, titanium valve spring retainers weigh 6 grams as against 20 grams oem. So between pushrods and retainers,a huge weight difference !!!!!!
 

bowie

Member
1000+ Posts
yeah thats great! will be annoying you in ~8 years where my build is nearing finish :p
 

Reidar

Member
I have lost the piston info over the years or recently when I moved. I think it is one of the two pictured below. Rather do a comparison with a Renault stock piston and see if it will work. The dome is not as prominent as in the drawing but has a great compression ratio boost. I have added some photos for you of the Titanium pushrod manufacturing process. The mushroom ends are turned out from stock pushrods and pressed into a pre-drilled Titanium rod. (solid 6mm or 1/4") It is a bugger of a job to turn the heads because of the hardness and being so thin.

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There is a few sets of those pistons on Australian ebay at a good price.
 

HONG KONG PUGGY

Member
1000+ Posts
Oh, seriously? The Datsun manifolds fitted. I'd have been more encouraged to go that route if I had known and might have even finished my R10. Argh. Sachre-blur HAHAHA
 

hulot

New member
Question re an earlier post on this thread.
Someone reported that 1289 liners won't fit a 842.01 block (1250 I believe)without machining. Can anyone confirm what needs to be done in this situation? Thanks
Rob
 
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