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Harry I said "nearly 200hp" so as not to draw exactly this sort of fire, but thanks for pulling me up as it is arguable whether 200hp from an naturally aspirated A series is actually possible.

bert, judging by your email address (rsouter@...)I assume you are the proud owner of the Vixen powered 150rwbhp 1000 2dr sedan - Rob Souter

if you would be so kind as to get the 'facts' right, I believe it is you getting his arse handed to him regularly by Craig Allen's red white and blue 108rwbhp 1200 coupe. Seems you neglected to mention that! I guess it would be quite embarrassing when you claim to have damn near 50% more power than him? And you with your lighter car too...

Yes Craig Allen in the other red white and blue coupe used to beat me when I had my 116bhp L18. We first raced together in 2002. You wouldn't know because you weren't there. I had a slight straight line advantage over their car and I had good dices with Malcolm Allen in that car, but simply couldn't match young Craig in the corners. He was too good. But he did only ever beat us on the exceptionally tight short circuit at Morgan Park, which was the only track there back in 2002, in case you didn't know. Because, remember, you weren't there. But for the record, Craig beat me by 6.7sec over 7 laps at the 2002 final, just under a second a lap which is a pretty convincing beating in racing terms. Mal and I however were seperated by 0.27sec over 7 laps. Unfortunately in his favour

In '03 the Allens and I were in different series, so there's no times to really compare there, but as i didn't make any changes to my car, the Allens would certainly have still beaten me. But again, you weren't there anyway, were you?

In 2004 you were though! And considering you claimed (and still do) to have more power than I had even with the good engine in my car that year, in a car that must be at least 100kg lighter, I am somewhat surprised you were so quick to bring results up here mate! But here they are, the QLD Super Sprint Series results from last year - you remember, the first year you competed there? This was when I borrowed the other engine you alluded to. Not sure where you would have heard about the 3rd engine you mentioned. The rumour mill might be gettng a bit excited there, mate. And for the record, I've never run anything but 1601-2000cc class. But you wouldn't know, because - that's right - you weren't there...

Anyway, this is why I asked if you remember the '04 QSSS, because here's the times which you seem to have forgotten:

Rd1 Short Circuit A 4 laps
Me 2:57.69
Craig Allen 3:00.56
bert (150rwbhp 1000 2dr sedan) did not run

Rd2 Short Circuit B 4 laps
Me 2:39.78
Craig Allen 2:42.57
bert (150rwbhp 1000 2dr sedan) 3:00.22

Rd3 Medium Cicuit C 4 laps
Me 3:45.66
Craig Allen 3:51.98
bert (150rwbhp 1000 2dr sedan) 4:06.80

Rd4 full circuit 3 laps
Me 2:41.27
Craig Allen did not run
bert (150rwbhp 1000 2dr sedan) 2:53.19

Like the saying goes, when the flag drops...


I'll be sure to come and say hi the next time we're both at the same event mate

Correct me if I am wrong. I have never raced a car in my life. But I was brought up to believe a number of things attributed to Lap Times, not just engine power.

My guess is, if I get the time, I will see these attributes at Bathurst.

hi all
sounds like my feral built motor's getting a bit of mention

the engine being mentioned is the 2nd serious A series i've had built-1st an A14, 2nd an A12.
both achieved similar results and both were built by reputable builders of the A series motors.

details are as follows :
A14 - cleaned up bottom end, pretty stock-no balancing, flat top pistons. 70/30 cam, big porting in the head and 1600 exhaust valves, double valve springs, and around 10:1 compression. Regraphed points dizzy. 4-1 extractors and 2 1/4" exhaust, single sports muffler. Dyno'd with twin 1 1/2" su's and acheived around 90hp at the wheels. Changed carbs to twin 40mm dellortos, never dyno'd it again. This motor was in a 2door 1000 sedan and extremly fun to drive, although nothing really started to happen till around 3700rpm. Engine built by Gordon Dobie at Datsun Performance Centre.


A12 - cleaned up and balanced bottom end, incl-flywheel and clutch assembly, pistons and rods, lightened flywheel, 9.78:1 compression(flat top pistons), 60/33 cam, head fully rebuilt and cleaned up, ports matched to GX gasket, cambers marginally reshaped, new double valve springs and teflon guides, flowbenched. 4-1 extractors, 2" exhaust with single sports muffler. twin 40mm webers with 30mm chokes, electronic datrats bosch dizzy regraphed no vac advance. this motor was dyno'd on the same dyno (at least 10yrs apart ) and acheived the following : all readings in 5th gear
@100kph 40kw
@120kph 47kw
@6000rpm 58kw
in second and third they wound the engine out to around 8500rpm without the power curve dropping off dramatically. Cam comes in around 3000rpm before it's really noticable. Feral calculated an approx of 68 ft/lb of torque at 6000rpm.
this engine is much nicer to drive and more responsive right across the rev range, as well as reving out alot further before things start to drop off. Engine built by Feral Errol at Datrats.

both engines "comparatively" cost around the same to build, even though 10years?? apart. The A12 did however start out as a worked ex-autocross motor.

so ........... after all that 100rwhp is achievable out of an A12.

thanks for reading and apologies for the long post but but this topic seems to come up a bit with no real figures, out come, or advice for the person who originally asked it, so hope all this helps ..... to not confuse it

100bhp or 100rwhp both very possible although the first comes much easier. So to answer the question. Yes 100hp is possible and cant be made any other way than the basics. Cam, compression, carbs, exhaust + headwork.

The argument on the 200bhp A-series. I believe it. The dyno sheet showed it and i really cant see why vixen and bert would lie about it. What would they gain. Absolutally nothing. Im sure mush more could be had from this engine. A high horsepower figure, especially in small motors usually means a preaky torque/power curve which in turn to be benefitted from needs suitable gearing. You dont see formula 1 drop back almost out of the power curve each time. Same with v8 supercars. 500rpm drop per gear keeping it where it counts. Berts car still has street gearbox ratios with street diff ratios making for a not overly exciting gearchanges. Each gear i assume would be almost if not out of the power band just about. With fine tuning of ratios in particular im sure it would be a very quick car.

And not to get too involved but Harry are you not in the 1600-2000cc class yet comparing your times to the under 1600cc class. Seems hardly fair and although your saying it should be quicker torque of the L im sure would be greater even with less HP. In my opinion its hardly a fair comparrison. Torque is easier to tune than horsepower for the amature. Most highly competitive forms of racing use horsepower yet they have the ability and mainly $$$ to do endless testing on ratios and what not to make the power useable.

The GREAT DEBATE, 200BHP or NOT? WHY NOT?

I'm nearly there (A15)
Once I change back to some pistons with compression rather than these fairy type ones that are in there now we'll be over the 100 mark for sure.
We only turn it to 6500 at the moment and there should be more in it despite the dip in the graph
Now if only I had the money for the injection setup for sale we'd piss in the 200 at the fly.... haw haw

yes phunkdoktaspok, there's more to laptimes than power, obviously. But when a 150rwbhp 1000 is visibly slower than a 108rwbhp 1200 in a straight line (both of them use production gearboxes with no fancy ratios), and the laptimes back up the fact that its slower, it tends to indicate that it doesn't in fact have as much power as claimed. And there's other similarly developed A series powered 1200's up here such as Adam's and Brendon Pingel's that also developed similar power to Craig's car and are also faster than the Vixen powered cars. And given that Vixen has been involved with the factory Datsun race team and really knows his stuff, if would be fair to assume that they also have these other factors covered off, phunkdoktaspok. I've seen thier 1000 in action and can tell you its strength is its handling, not its power. Its cornering speed is good, and it never does anything nasty. Looks nice and nuetral and responsive on the track.

Freak, I only compared those times for the sake of correcting bert's statements. At the time I was always dicing with the leaders of the 2001-3000 and over 3001cc classes. And more interested to see how I was going against the big sport sedans and sports cars on their slicks.

And as for the fairness of the comparison, I'd say you're right, its not fair to compare my car to one that weighs well over 100kg less (probably over 150kg less) with more bhp. It would have a massive advantage. If it were true, that is.

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simple mate. Volumetric Efficiency, Brake Mean Effective Pressure (BMEP), and 35 years of people playing with these engines all show that it is not realistically achievable. Go dig up the other threads where it has been discussed for starters.

The magic 200hp figure i believe has to be possible. It may not be reliable by any means but im sure its possible. I have read the other threads and no-one said its impossible. Its not like anyone has really experienced it first hand anyhow. Nor have i but by what somepeople say you'd think they have although you can smell the utter bullshi-t.

By this stage the little a-series is basically at its uttermost horsepower potential. You cant tell me that just that little bit bigger cam with maybe just that tad more flow with revs now well exceeding anything somewhat reliable can not do it or at least have a damn well decent crack at it. I believe nothing is ever at its peak until its broken. Thats when the line is crossed.

We need someone with plenty off folding stuff to give it a crack. Make the little A-series hit the 200mark or if not may we be proven wrong.

I just think its wrong to say its totally impossible. I couldnt see it just hitting a certain figure on the dyno and saying, Yep thats it. Handgrenade or not.

I agree with you Freak!
I just done some number crunching. I hope I've got this right...

200HP out of an A15 bored to 79mm requires something like:
1) BMEP = 200psi at 8100 rpm
2) BMEP = 210psi at 7700 rpm

strength issues aside, these BMEP's are definately possible but to get them at those rpms will require some serious porting and compression.

I'm still a believer!!!

I think you would be challenging bock integrity at those power outputs, so. . .

We will need for starters, a ceramic filled block, methanol injection and 15:1 compression(maybe more?).

What about crank flex?

Weld the main caps on?

Who has a few spare $$$'s ?

(of course there is a little more involved, I have only got just over 1/2 way there myself. . .)