just bought 3 a13 engines over from the states and can anyone tell what when where how wtf i have bought that is "special"?????

The A13s that the united states got are reduced-bore A14s. Same crank and block as A14, but with A12-sized pistons. They were only used for one year, the 1974 model year in the first-year B210.

thanks for clearing that up dd. has anyone out there had much to do with these engines? cheers scott

In the USA these engines were used in Sports Racers, specifically SCCA D-Sports Racer. The class limit for automotive based cars is 1305cc , a lot of the race parts are floating around for these engines as most competitors have gone to 1 liter bike engines (also legal for the class).

The race prep for them is pretty much the same as other A series engines with a couple of exceptions. First instead of side draught weber carbs Keihin FCR Flat Slide carbs were commonly used, since the sports racer engine rules are more liberal so 10,000 RPM redlines were common, the next step was E-Series cylinder heads bolted to A series bottom ends...........there are a couple of those sitting around in storage in the USA. Other than that it's all the usual stuff Nismo Option 2 or similar Camshaft, 14-1 compression, Carrillo Rods, Larger Valves, Competition Head, Extractors, dry sump crank fire ignition etc. Be advised this level of prep means 4-6 hours between engine tear downs. In fact I've seen some guys with A series powered cars checking the screens in the race filters at the end of the day....just as a precaution.

The A13 might be a good nitch as those of us who run vintage run the A12 and people still running modern tube frame cars tend to run A14's so you may score some good deals on A13 hot rod parts. There is a site called SportsRacer.net (I think) but id you plug in D Sports Racer in a google search it will come up.

Tom

thanks tom. i will investigate soon. also what is good hp atw for a a12 or a14, or does a hp tread already exist?

We gave HP listed in the Performance article in the wiki. 90 HP at the flywheel is a good figure for street engines (regardless of size, A14, A12 same peak HP).

But no figures for 4-6 hour (all-out) race engines.

Keep in mind the figures I've heard are anecdotal. A12 140HP, this sounds close as PJZ has told me a couple of times that 100 horsepower at the rear wheels is a good race engine. For A13 155-160HP is what I seem to remember hearing and on A14's someone I would consider in the know said 175HP.

For the A series with E-series head I was told 180HP,I would believe that as it was from folks who had front running national cars. They would have had their engines on a dyno so I'd take that to be accurate.

Realistically if we had access to real dyno figures I would expect A12 at 135HP, the A13 at 145, and an A14 at 152ish.

The final wrinkle would be powerband, I seem to recall Jeff Wirth's A series cars ran lower RPM's 7800 and higher compression 14-1 or more with the aim of higher torque. This would make sense as I do know that 250cc 4-stroke & 125cc 2-stroke generally make the same peak power but the 4 strokes are faster overall due to the extra torque.

Tom

thanks tom, is that flywheel hp or atw hp. cheers scott

All-out racing A12:
100 at the wheels
140 at the flywheel

Remember, all car engines are rated at the flywheel. Only racing & aftermarket dynos measures it at the wheels.

Kazumasa Hitota's TS Cup Tomei car with a12 out to 1300cc makes 170hp at the fly.