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Cam Shaft A12


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Yes it will fit but it is not an improvement over the old one. Just newer. Keep your eyes open for an EI distributor and matching coil from a '79 A14 or A15 engine. It has no points to adjust or wear out and has a higher voltage output.

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  • 2 weeks later...

Hi!

 

If you please i need a advice from you.

 

As you know im rebuilding a better A12 engine with some performance parts (better camshaft, twin mikunis, A14 Head, a14 Mainfold) and i thinking to improve my cranshaft.

 

It worth or i keep it in original way..

 

Please give me your advice

 

 

Many thanks on advance

 

 

Luis

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As you know im rebuilding a better A12 engine with some performance parts (better camshaft, twin mikunis, A14 Head, a14 Mainfold) and i thinking to improve my cranshaft.

 

It worth or i keep it in original way..

A12.... bore 75mm stroke... 70mm

A14.... bore 76mm stroke... 77mm

A15.... bore 76mm stroke... 82mm

 

Seems like you could bore your A12 to 76mm (or 1mm) over size and put either A14 OR A15 crankshaft, rods and pistons in it to make it, a larger displacement A14 OR A15.

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Hi
 
Many thanks for your all answers, but i want to know if i Lightened my A12 crankshaft makes a big diference on engine performance.
My doubt is: the engine with modifications will gain more HP and the standard crankshaft will support more pressure on main bearings, or the original cranshaft will support it? The rpm will basic the same. I dont want spent money for nothing...

 

In other way i bought  the A12 GX distributor R D412-53K, i want to know if i gain anything with it King Rat? Please let me know where i can find technical information about it  (I want to know if i gain some dwell angle) O

 

Once again thanks all of you

 

 

Luis 

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If you want to reduce spinning weight get an aluminum flywheel, aluminum driveshaft, magnesium rims and lighter tires. I wouldn't mess with the crank.

 

I don't know anything about the A12 GX distributor R D412-53K distributor compared to what you have. Later A series distributors are high output and electronic... without points. 

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  • 7 months later...

Hi!

 

 

I have stock valve spring on my A14 cylinder head with a regrind cam 266º total intake/exhaust time, Some menbers advice me stiffer springs (what does it meaning?)  and his is enough for the cam regrind i have?

 

Double springs is a waste for this specifications?  If i buy them i will need buy valve spring seats and retainers too? or my valve spring and retainers will fit the double springs? Im afraid if the engine take more rpm that normal and some valve spring jump out the valve and broken everything? Please advice me because im assmbing the engine and i need to assembly the cylinder head. Or the stoclk valve springs are just enough? 

 

Many thanks on advance

 

 

Luis

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Many thanks for your quicly reply.

 

Where i can find these stiffer springs to replace my stock ones.

 

Please give your technical advices. Give me the shop name? to contact them

 

 

Which are the diferences between stiffer springs and double springs. What are the best?

 

I want give to my engine a increase of some power and i need to have in safety the valves and all engine. I want to press the gas pedal at red line sometimes and dont break anything.

 

 

The standard engine i have no problem i can press the acelerator to red line and i dont have any problem, but with a difrent camshaft, twin carbs diferente distribuitor, diferente mainfolds i have my doubts?

 

Please advice me   

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Here's the thing. The springs you have now may be fine, I don't know. Generally they will work fine at lower speeds but at high speeds the valve train has a hard time staying pressed against the cam lobe and following it when closing. In effect the lifter, push rod, rocker arm and the valve are 'floating' just like a car racing over a hill can leave the ground. A higher lift cam and higher RPMs will do this. This may... or may not be the case here. 

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The valve locks can't jump out. The valve may 'float' but that's all.

 

Another thing to check is, if your stock spring may not compress enough with a high lift cam. Just install one and turn over by hand and see of you can get a proper valve lash clearance.

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Hi!

 

I have the engine completely in spare parts. The only thing that i have in order is the cylinder head. So when i go assembly the cylinder on engine i dont want take it off again. I have to do is: mount it with the original springs or buy stronger ones or double ones.

 

My doubt is the speed of intake/exhaust are increased by the duration of camshaft and the stock springs may not follow it and the engine can run well with perfect strokes

 

if i dont improve  any benefits with strong or double springs i will keep the stock ones.....

 

What do you think?

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You don't have to remove the head if you later decide you need to change the valve springs.

 

I don't think the valves will open faster but they will open farther. This is like hitting a larger bump in the road than a small one. The valve train may have trouble following the 'bump' on the cam.

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  • 1 month later...

mY a12 actual performance              ikenderian grind

 

total intake timing         248º                     266º

open before tdc              14º                       24º

close after tdc                  54º                      62º

 

totalexhaust timing

open before tdv              56º                        62º

close after tdc                 12º                        24º

 

 

with iskenderian regring can i keep the original sprocket gear? Its not necessary buy ann adjustable one?

 

I read and i know when a cam is ground, material is removed from the base cicrcle but in my case can i timing the engine with the original sprockets?. and follows the original marks on chain and sprockets? The only thing that i have to do is advance a litle on ditribuitor.

 

Many thanks on advance

 

 

Luis Colchete

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