"Will it Go Round in Circles, Like a Bird Like a Bird Up In The Sky" Engine Choices.

To paraphrase a Billy Preston song I find myself in a circular pattern yet again.

The overarching philosophy behind most of my fleet, be it the old bicycles, motorcycles or cars, is that the driving or riding experience be what it was back in the day.

This typically works well with the sole exception of my Datsun 1200. At least once a year I get the urge to make it faster but there is always a fundamental hitch. 

The current plan is to simply install the best bits I have. After this coming weekend's race we'll be installing my so called race motor, which will bump the power up to around 90hp at the wheels. At this level there motors go 5-6 seasons. The only hitch to this option is the car is still slow. Basically it will just keep up with a bone stock NA Miata down the straights.

For track days and SCCA time trials I can build a full 1600cc engine using an A15 block and get around 125hp at the wheels. This is almost 50hp more than it has now. I can also with a much modified Sentra E16 crank get a 1700cc motor that would like net around 135whp

The issue with 1600-1700cc motor is will may knock me out of the run group I'm in at vintage races. It puts me in B-sedan with cars that are running between 185-220whp and that sort of defeats the purpose of making if faster.

I could do a 2.0 motor swap and run with the B-sedan cars but frankly with all that I have going in my personal life I don't have a motor swap in me. I'm also way to cheap to pay to have it done. 

If I am going to motor swap it then a V8 makes the most sense (I even have an extra 5.0 motor).

So once more, like a bird in up the sky, I go round in circles.

I figured many folks here could relate to this.

Could you do the 1600cc engine and tune it to where it just keeps you in your current class? 

There is a certain west coast Miata shop known for tuning their engines to limit of hp:weight class limits and ending up with the correct peak number, but much more "under the curve."

In reply to z31maniac :

Sadly the class, C-Sedan, has a 1300cc limit.

From 2012 to 2018 I was running a 1500cc engine that put out about the same horsepower as a fully built 1200cc race engine; so the performance was what one would expect for the car.

I simply ran in vintage GT-lite within the same run group; I was the only car in that class so I would see how far up the overall I could get. Unfortunately other GTL cars started showing up and they were running the 2.0 engines that the class allowed and we got put in with the medium bore cars.

I prefer the small bore group.  

How about using an A12 crank in an A15 block to get a high RPM screamer - does that have any advantage over the current motor?

Or just get a 500 hp LS crate motor and add a dry sump. 

MadScientistMatt said:

How about using an A12 crank in an A15 block to get a high RPM screamer - does that have any advantage over the current motor?

Or just get a 500 hp LS crate motor and add a dry sump. 

I did some figuring and if I use Kawasaki 1000 pistons I can build a long rod motor that way. No clue if it's worth extra power.

What will all that power do to transmission life?

That's a serious question.  I haven't seen the transmissions that these small Datsuns came with, but I've handled the trans for an Opel 1.1l four and I bet the whole thing, case and all, would fit inside an empty T5 and rattle around.  The gears in there have to be watch-like, fluid capacity measured in cups.  And the T5 is not a transmission known for its strength.

I don't see Datsun putting the 240Z transmission behind an engine half its size and a quarter the power.

As a fellow vintage racer of a slow car, what I most want is a good race.  It could be driving the wheels off my car to keep up with a less skilled driver in a faster car.  It could be barely keeping up with a much better driver in a slower car while I drive a faster one.  The first is more satisfying, but only barely.  It could be that we're evenly matched.  I don't care about winning at all--I've never done it.  I may never.  I'm just as happy racing for second-to-last as I am the lead, if we're well-matched.  I recently bought a much more modern FV (Mysterian that's barely legal for vintage in my club) in hopes of racing with the other folks with modern FVs near the front of the pack.  Different class, same run group.  While it's true that 1st in class generally feels exactly like 3rd overall in a mixed rungroup, my motivation for a faster car is just to switch things up and a learn a new, more capable car and have different races.  I might make the Zink into a monoposto car, which would make it slower and mean racing in the back of the pack.  I'm just looking for fresh, good, wheel to wheel racing.  Improve my skills and dance with my friends on track.

Where are you likely to have the best races?  If running around in a different class (and/or run group) is worth spicing it up, add 50hp and see what the racing is like.  I will say that, all else being equal (and it never is) the quality of the opposition is better at the pointy end of the run group.  You'll notice 50hp for sure, but you and I both know that hp and fun on the track might actually be inversely related.  What are you looking for?  Maybe save the money you were going to toss into an engine and go to a race somewhere new...

I don't, however, know how you feel about competition.  My anti-competitive spirit is more at home in vintage racing than most racing groups, but I'm less competitive than most of my fellow racers.  If winning is important, pick the thing that will make you win.  I'm guessing that's not a Datsun, though:)

In reply to Berck :

When the car had the 1500 that 99hp to wheels I was running 5th overall in the small bore group.

The 1200 in the car now makes between 76-80hp at the rear wheels and I'm managing between 9-12th overall.  There are typically 4-5 cars in my class. I manage to finish between 2nd and 4th in class. It totally depends on how many of the Minis break. They have more money in their motors then I do in my car.

Our motto for the car is "faster than a set of bleachers". I am out there to have fun and I usually have someone to race with. 

This is a typical lap of a typical race for me. There's a Fiat X1/9 hot on my heals, he gets by down the back stretch but then gets into a tank slapperand I get back by.

https://m.youtube.com/watch?v=Mj2sQYuonjc&pp=ygUOU2N1ZGVyaWEgcG9rZXk%3D

That's some pretty fantastic driving.  Seems like all I'd want out of a race!

Billy Preston had a Hammond organ gospel music side to him.

In reply to Datsun240ZGuy :

As a Catholic guy who got married in a black Baptist church I can identify with this.

In reply to Berck :

It was glorious fun as we were both trying really hard.

And your right it really was everything one could want from a race. 

Much like your Formula Vee you have to work hard to get the most .out of the car.

Tom1200 said:

Our motto for the car is "faster than a set of bleachers".

That's awesome.

OK, so you need what, about 20 HP to get results in the existing class.  Take that goal to an engine builder you trust and see how much it will cost and how many hours you will get between rebuilds.  

But it also seems you are in a BTDT moment and the end result seems to be the same.  But if you are looking for enablers this is the place.

So there appears to be four goals:

1. Want to go faster

2. No engine swap

3. Want to continue running vintage races

4. Want to continue running SCCA, etc

I don't see a solution without changing or removing at least one of these. One way is to order the requirements by importance/must-have, then deciding if you're comfortable discarding which ever one is last on the list.

porschenut said:

OK, so you need what, about 20 HP to get results in the existing class.  Take that goal to an engine builder you trust and see how much it will cost and how many hours you will get between rebuilds.  

But it also seems you are in a BTDT moment and the end result seems to be the same.  But if you are looking for enablers this is the place.

Super high compression + E85? 

Seems like your car, no matter what you do to it, will not be a contender at both the track days/time trials and the vintage races you do. 
 

so pick one and build it for that.    Track days aren't even competitions so, to me, it reduces to time trials and vintage races.   Which is more fun for you?  Which would be more fun if you were fighting for a podium?

Perhaps use/get a daily driver you can do tt/hpde events with and save the Datsun for the racing you love.  A newer mustang or Camaro or Vette or 911 or cayman or m3 (or similar) might give you what you want for the time trials and track days   

porschenut said:

But it also seems you are in a BTDT moment and the end result seems to be the same.  But if you are looking for enablers this is the place.

Yes there is a whole lot of been there done that. I briefly owned a very fast front running car.........sure setting a lap record made my ego feel great but the level of effort made racing less fun for me.

The Datsun is doing donuts in a muddy field with your mom's car at 2 AM kind of fun. 

And yes, yes I am looking for enablers..............or at least a different perspective from mine.

jfryjfry said:

Seems like your car, no matter what you do to it, will not be a contender at both the track days/time trials and the vintage races you do. 
 

so pick one and build it for that.    Track days aren't even competitions so, to me, it reduces to time trials and vintage races.   Which is more fun for you?  Which would be more fun if you were fighting for a podium?

Perhaps use/get a daily driver you can do tt/hpde events with and save the Datsun for the racing you love.  A newer mustang or Camaro or Vette or 911 or cayman or m3 (or similar) might give you what you want for the time trials and track days   

 

You nailed it; as a dual duty (vintage / time trial) car there is no way it will ever work for both.

I have the most fun at vintage races. What I care about most at vintage is seeing how high up the overall order I can finish.

Now as for buying a Mustang; I bought a 90 Foxbody last year and we're having fun running CAM-T at autocross and will be running it in the Sport Category at SCCA Time Trials. 

In reply to Tom1200 :

You seem to enjoy wringing the car out, but always think how much more fun it would be with a few more ponies.  There was a joke in the local PCA that the monday after a DE weekend was always busy time for the local performance shops.  At least you are honest about what you like, hope someone here has an idea that works for you.

When I had my 1200, I always wanted to drop an rotary engine in that had been ported mildly. A compact motor that was about the same weight, but you could get about 170 HP pretty easily. I'm sure that it would take me down the path of needing bigger and better brakes, stronger gearbox and axle, etc. But it was fun to think about!

porschenut said:

In reply to Tom1200 :

You seem to enjoy wringing the car out, but always think how much more fun it would be with a few more ponies.  There was a joke in the local PCA that the monday after a DE weekend was always busy time for the local performance shops.  At least you are honest about what you like, hope someone here has an idea that works for you.

I think jfryjfry is really on the right track.  

I need to commit.

So that means make the most of the 1200 in Vintage trim and when I'm feeling the need for something more at track days / time trials bring the Foxbody Mustang.

RacerBoy75 said:

When I had my 1200, I always wanted to drop an rotary engine in that had been ported mildly. A compact motor that was about the same weight, but you could get about 170 HP pretty easily. I'm sure that it would take me down the path of needing bigger and better brakes, stronger gearbox and axle, etc. But it was fun to think about!

My ultimate fantasy build 1200 was one with a Cosworth BDA.