with the a-14 you are competing in the next class, usually under 1600cc

putting an a14 crank into an a12 block gives what is an a13,my gregorys 120y manual gives the capacity as about 1270 or so,can't find it just at the moment to be sure.as for a10 rods,they can't be too common any more.i've been told this combination has an etremely bad harmonics problem(flywheels fall off easily).i also thought the class capacity limit was 1300cc,so if they running over they're very naughty boys.sold the a12 out of my old 1000 coupe hillclimb car to some prc rally guys,1298cc,revved off the dial,they were too afraid to go past 7000 in it,cause then all hell broke loose,& they got scared.nice to know that you can impress people with 1300 cc's. paul.

dunno but im pretty sure its the rules, and ive heard of 1200's that used to rally with them, the guy i bought my motor off poured heaps into an a12 aswell, i dont really know why. i bought it cause for the price its going heaps better than any a14 i could have bought, in the next couple of days im gonna ring cams and make 110% sure its a homolagated motor but im still sure it is

Since when have you been allowed to use A14 in a 1200 PRC rally car?? I thought they had to run with the engine that came in them.I doubt they would spend the money on building a stroker if they could just run a A14.
cheers andrew

rally guys are allowed to use a-14 block cause of that ute sold in africa but anyhow

Another good point is a lot of the rally guys are stroking the A12 engines with A14 cranks. In there class you must use the A12 block but modifications after that are open I pretty sure they use A10 rods and modify the block to clear the crank Im also pretty sure they can get just over 1430cc out of them with a big bore job. My old engine builder (JTS) in stmarys sydney has done quite a few. The extra machine work and custom pistons ect would become quite an expensive engine. Its not hard to spend $5000 aus on a hot Aseries.
cheers andrew

Thats a good point about the cast crank ,it's something I had forgotten about. My experience with stroker A series motors has involved the use of custom made cranks from Cosworth in England. I have 2nd hand one stashed away for another dream project. I still reckon you could safely modify a forged A14 crank though. Building these types of engines require very careful machining and assembly and even more careful planning.

Yes, I did contact Malvern racing about a year ago about performance parts for an A 15 engine,and he sugested going 120thousands,I have the e-mail at home,I kept it for future reference,I will look at it and check exactly what he wrote to me then.
Jaime.

When Steve a from Malvern Racing suggested boring to 1600 , I rejected the idea as not very cost effective. I have my old extremely high revving A12 but it has a burned piston and scarred cylinder wall. I have always assumed that the wall was so badly scratched that it couldn't safely be bored out without sleeving it. I really had not thought of offset boring but that may be practical for the old A12. I will have to check out the block when I get back home.

There is a notch at the top of each cylinder on the intake side that I had always assumed to be the safe boring diameter. I really haven't measured the notch to see how large the cylinder can go. There is only about .250 between 1&2 and 3&4 cylinders so boring to 1600 CCs is not practical and Steve at Malvern Racing is not what I consider reliable information.

You were very right about the A15 crank, B310GX, they are cast (and not as reliably), not forged like the early A14 and A12 cranks. I have seen a lot of 79 - 82 A14 cranks that are cast also. The only stock cranks that I would even consider using are the forged A14-H72 cranks from the 80 HP engines.

When I first contacted Malvern Racing, it was for pistons for the A14. Steve there suggested the A15 bore and I ran the idea here for input because I didn't think it was feasible. I still don't. 97mm is Chevy/Ford size, not A-series size.

I am now waiting on Malvern Racing to reply with my original question and a catalog. I think he just wants to sell more parts, not sell me what I want. I just want to have a fun motor, not a monster.

My friend that has the machine shop that I have used since the 60s has retired this year so there goes a world of knowledge that is now unusable. I have to go outside his realm now and I just do not trust everyone's knowledge. I have heard too many nightmares to take one person's opinion at this stage of life.

I love this club because there is very reliable knowledge here on the 1200. Thanks everyone.

Mareo

also noticed someone suggesting offset grinding the crank,please don't.the a15 crank isn't as tough as an a14,& by offset grinding you weaken it further.have seen too many cracked cranks,in fact the first a15 i bought came complete with one,to not mention this.looking at the crank shows how little support there is between big ends & journals,in fact i always get any a14 or a15 crank i use crack detected then nitrided as added insurance.sure they always seem to bend during nitriding,but they can be straightened afterwards(wilkins performance in seven hills has straightened all 3 of my cranks for me).