Assistance Required-Oval Track Race Car

[MR88]

Hi

 

Need assistance or at least guidance.

 

I compete in oval track racing in South Africa and compete in the 1660 class(Maximum 1660cc allowed).

Obviously there are rules to what you may and may not do on the mod side of things.

 

I have built up an A15 motor and spent loads on getting it to the max,it roars down the straights and is extremely competitive. I have managed to squeeze out 88kw/141nm at 5500rpm which is class leading,but like any other petrolhead,I want more!!!!

 

The question is,will the L16 motor give me more with the specs that I have to stay within? From reading earlier posts,I have picked up that the L16 has alot of lag before it gets going, can this be improved?

 

I have added the rules section, hope someone will be able to guide me to another powerhouse engine!

SS 3.

3.1

3.2

3.3

3.4

3.5

3.5.1

3.5.2

3.5.3

3.5.4

3.5.5

3.5.6

3.5.7

3.5.8

3.5.9

3.5.10

3.5.11

3.5.12

3.5.13

3.5.14

3.5.15

3.5.16

SS 3.6

No aftermarket electronic ignition system may be used

SS 3.7

3.7.1

3.7.2

3.7.3

3.7.4

3.7.5

The following items are in particular not permitted:

Dry sump lubrication not permitted;

No racing type forged pistons may be used;

Flex plates are not allowed;

Electronic Water Pumps not permitted;

Roller rockers not permitted.

General Racing Modifications

The following listed modifications shall be accepted as racing modifications in the class:

The following items are permitted:

Flywheels may be lightened and cast flywheels may be replaced with steel or Aluminium fly wheels, no flex plates.

From 31 December 2011 fly wheels are free but no flex plates.

The following items are free:

Pulley sizes;

Pistons and piston rings (no race forged pistons allowed)

Connecting rods to remain standard. Balancing will be permitted for that purpose only;

Crankshafts;

Compression ratios;

Bore and stroke ratios;

Valve and tappet covers are free with the condition that the cover does not form part of the valve train;

Sumps are free in respect of volume and design;

Fuel pumps are free with regards of operation and capacity;

Camshaft profiles are free as long as the number of lobes and their location are not altered;

Flexible engine mountings may be made solid;

Fuel pressure regulators;

Dellorto and Weber carburetors parts may be interchanged;

Induction and ram tubes;

The method of camshaft drive may not change;

Pressure plates and button clutches are free.

[datzenmike]

88Kw is 117 hp. not too shabby for a A series.

 

 

The question is,will the L16 motor give me more with the specs that I have to stay within? From reading earlier posts,I have picked up that the L16 has alot of lag before it gets going, can this be improved?

 

Lag? I don't think so. It's overhead cam, short stroke and likes to rev. Came with a high compression closed chamber head with larger valves and ports and flattop pistons and the exhaust is basically a cast iron header. Other L series heads will fit it. There were factory camshafts available. 1mm oversize stock pistons will give a 1632cc motor. (L18 pistons go over the limit 1671cc)

[MR88]

What is the weight difference between the A15 and L16 engines? And will the L16 fit inside the engine compartment of the GX? Figure I should build up a L16 and see what I'll get.

[datzenmike]

The L16 weighs about 250 pounds. If a 4 cylinder fits, then an L16 will. You'll need a transmission for that.

[MR88]

A quick scan through my local classifieds show L16 engine and Transmission for R2500, thats roughly $300. Includes intake and branch! Would you say thats a fair price?

[ggzilla]

Track racers here get 150+ HP out of A-series. If built cleverly the A15 @ 1660cc will make as much peak HP as an L16 @ 1660cc. But it will be easier to do with the L-series as there are large heads commonly available.

 

Weight

A15: 205 pounds

L16: 250 pounds

 

The factory put L-series engines in B110 GX, so no worries there.

[ggzilla]

$300 is what one goes for here that needs no rebuilding. Take a starter, transmission and battery, and perform a compression test before you buy it.

[MR88]

Will do! Any advice on what I should do,eg Skim Head and porting,pistons,flywheel etc. I usually do the full balancing thing and port matching and so on,but what is the other little secrets that will make the difference?

[ggzilla]

L16 is fully balanced from the factory.

 

You are giving up over 50 pounds by switching to the L16. How did you get 1660 cc from the A15? Normally it would need a slight offset ground crankshaft and custom cast pistons. Although with sonic checking you might get it all with an overbore. I wouldn't go over 8500 RPM on cast pistons, but maybe that's enough for 150hp. Contact peterzekert.com for parts and advice for getting 150hp from an A15 track race engine..

[datzenmike]

There are lots of head choices with big ports and valves. http://www.olddatsuns.com/html/tech/head_ID_2.htm

 

A '78 and up L20B intake has larger runners.

[MR88]

I'm only pushing 1528cc with the current motor(the 88kw/141nm at 5500rpm), 77mm pistons, Mazda E5 pistons,3mm off the head,porting,316 degree cam etc. Been told by the old timers that going bigger on the bore will kill my torque, my back up engine is at 1598cc ,79.5mm bore with all the same works as the 1528cc and only pushing 85kw/132nm.

 

Ran a 3:9 diff ratio with the 1598cc and a 3:54 ratio on the 1528cc motor, the 3:9 runs out of revs before I hit the bend and the 3:54 has loads of revs but just not enough straight left, thinking of trying the 3:7 diff,which models came out with these?

[ggzilla]

Run out of revs? Are you revving it to 8500 or 6000? What's your engine built for?

 

You can get 1608 cc with a common 79mm cast piston in an A15. So you are giving up CC to the competition...

[datzenmike]

Don't know much about your cars. Have you thought of changing the tire diameter size to get you nearer to ideal revs? Smaller tire higher revs, larger tire lower revs.

 

What is your maximum revs? Because 3.54 sounds kind of low. I know a turbo car with 4.625 diff and at 7,500- 8,000 RPMs he's close to 140. Uh about 230KPH

[MR88]

Ok, let me go into more detail:

 

The engine is built for Oval track racing, the track has two straights at around 120m (think 393 feet) and two bends of around 140m(459 feet), its all about acceleration out of the bends,top speed into next and skill getting it around the corners. I dont have a video for you but if you go onto Facebook and look up ZA Racing Gallery there are loads of pics which would give you an idea of the track layout. The car is lowered to 0.495 feet off the ground,and running on 13 inch tyres,the 14's are just too big and I lose quite a bit of grip and to be honest havent tried 12 inch wheels yet.

 

The class I race in is 1660cc,I have built two engines:A- 1-1528cc (88kw/141nm at 5500rpm Dyno tested) 77mm pistons

2-I come out of the bends at 5500rpm and hit the next bend at 7500rpm

3- I run on sidedraughts DOCE 40 using Menthanol

4- The straights are around 120m long and using the 3:54 diff ratio there is not enough straight to reach max revs

5- The other guys in my class run at 8000 - 9500 rpms with Mazda and VW engines,this said, illegally as the rules clearly state that 1800 and 2lt heads are not permitted. Scrutineers not very bright this side of the world!!!

 

B- 1 -1628cc (85kw/132nm at 5500rpm Dyno tested) 79.5mm pistons Mazda flat top pistons

2-I come out of the bends at 5500rpm and hit the next bend almost touching 9000rpm

3- I run on sidedraughts DOCE 40 using Menthanol

4- The straights are around 120m long and using the 3:9 diff ratio,I run out of revs halfway down the straight

5- There are actually still a few things that I need to do to this engine,could possibly top the other.

 

Hope the additional info helps a bit more, my main aim is just to whip the illegal cars in my class soo bad that it just has to hurt!!!!

No Turbo

No Gas

Just a Datsun

Kicking your ass!!!

[datzenmike]

Depends on the tire but you can get 13" tires that are taller than 14".

[ggzilla]

ah, methanol is lower output than gasoline, isn't it?

 

1628 cc is much better.

 

If 3.9 is too high and 3.54 is too low, why not try 3.70?

[banzai510(hainz)]

"Zed" on here is from S Africa. Has a L18 which has same block height(Blocks same on outside)

Maybe he can help

 

you can swap around soem L16/18 to cheat a little if you just got to have a L16 stamping on the block.

L18/20 cranks are counter weighted

 

L16s are NOT