hi guys, im going to be building a new race motor for the coupe. so im doing some homework.
what i would like to know is how far a A15 can be pushed in the head work department, what a deacent cam spec for an engine to rev to 8 or 9 grand, possibly 10, what is the biggest valve size that you could go, and what sort of roller rockers and push rods have you used?
and what rods and flattops are used for a 1600cc engine with a 79mm bore
some guidelines are, i will be mainly looking at a 3j improved production racing, in the 0-1600cc class, so there will be a bore size of 79mm max with std stroke
thanks for any information
also i have herd of the name jeff taylor, has anybody got a website or anyway to contact him?
cheers guys kurt.
p.s. i know with engines anything is feasable, im just after some guidelines

i could help u on items and info contact me ernie 0412 864 741 ate race engines thank you im in sydney

http://www.jtsperformanceheads.freewebspace.com/index.html

jeff taylors website, probably best to ring him (hes oldschool) very nice guy

im looking at offset grinding the crank too, what sort of grind do you do to get a stroke of 88.5mm against the standard 82mm?

Remember that the existing 82mm stroke is pushing it already, The factory had to notch the A15 oil pan to clear the rods & you want to add another quarter inch to the stroke.

If you have an A15, then I suggest that you mount it in your stand, invert it, pull the pan & turn the crank while watching very closely at how much clearance you have in there. It's not much at times.
I believe that the end of the oil pump shaft comes pretty close to something.

I suspect that to gain another 1/4" on the stroke you would need to weld & grind, but by offset grinding alone & using 1mm oversize bearings [on a 1mm undersize journal] you will gain 1mm increase in the stroke, but that would be the limit using this method.

"how long is a piece of string??"

I agree with Dodgeman...you're wasting your time trying to stroke up an A15 in the <1600cc class. Besides, if you want a reliable A15 race motor on a budget then you can't afford to replace the crank with a custom steel unit, and you can't afford to reduce the bigend journal anymore than absolutely necessary. That is a weak point in the crank. I can show you photos of cracked journals if you need proof.

you can take the headwork "all the way" and end up with a slow engine if you don't match all your components together.

So what RPM is it?? 8000, 9000, 10000 ??? I would suggest you will struggle to keep an 8000 rpm engine reliable under race conditions unless you have a big budget and/or heaps of experience. The odd excersion to 7500/8000 rpm in a road car is different to holding it flat for minutes at a time. Chris Peto "the boss" has been racing his 1200 for..um...about 15 years or so??!? Dodgeman or Aiden might correct me here. he revs his to what sounds like 8000ish but also has created a lovely collection of boat anchors over the years - and that's when you know what you're doing. We limit ours to 7000rpm and have shelves of broken bits.

There's heaps of piston options. Thats why I asked you those questions before.

You asked for a guidline - as a starting point, why don't you consider the Wade 54/86 cam with twin 40's and a nice match-port manifold and extractors plus free flowing exhaust. The 1200GX head is a great performer especially if the ports are cleaned up (not increased). But you can port a standard oval port head to the same dimensions and use cut down L16 valves if you don't have a GX head. Double valve springs are a must to avoid piston to valve contact that will destroy your engine in a blink. Get a new set. I don't use roller rockers but Yella Terra sets are available from Repco. Others on this site have experience with them - try a search.

Mazda have a lot of pistons in the 78 to 80mm range. If you want to use cast pistons then the ACL catalogue can be downloaded from their website. Check out the B6, E3, E5 and UC, just off the top of my head. You will need to increase the small end of yoru rods from 19mm to 20mm, ask your local performance shop. You will need to know what compression you want, and before that you will need to know your cam specs. Then you will need to work out what valve resesses you need in the top of your pistons to ensure adequate clearance. I use 0.060" of vertical clearance and 0.040" of circumferential clearance.

I've also heard of galant pistons with 19mm pin, but can't remember wether that was an A14 or A15.

Ernie is selling 80mm forgies - check out the classifieds.

88.5mm stroke is excessive to say the least for the a series short block height.. Unless you can increase the block height with carefully welded deck plate, sleeves and longer lightweight pushrods.

Some of the best race engines have 86 - 90mm strokes but have the right block height for longer rods to help with RS ratios.

I dont think 85-/+0.5mm is excessive though with the 133/134mm rods.
By using motorbike rods with 35-40mm journals inbuilt threads (some are titanium) and available in 133-134mm (have to research this yourself as rod dimensions of stock bikes is not easily found.) you will be able to get this slight increase in stroke and not have to overbore beyond 77 -/+0.5mm.
The midrange should be better than the 82mm stroke and longevity can be increased as can heat transfer between piston bores. If something goes wrong you can safely re-sleeve to remain within the 1.6 class limit.

In offroad racing circles where torque is favoured over hp the suzuki 1.6 with 1.533 RS ratio does wonders with durability once the rods and rod bolts are replaced with quality items and well balanced.

my mates race car is running 15 to 1 compression so my mate reckons but if u seen this thing ud probly agree

It runs on Methanol [Alky] of course.
Nobody makes a regular type of petrolium based fuel with an octane rating high enough to handle that kind of compression.

Methanol LOVES that kind of compression.