performance upgrades

[1974datsun]

i have a 1974 l18. i have it bored .50 over and i still wish i could get more hp out of my motor. what other performance upgrades can i put on it

[Braden]

i have a 1974 l18. i have it bored .50 over and i still wish i could get more hp out of my motor. what other performance upgrades can i put on it

 

cam, dual sidedrafts, head, high octane fuel, etc., look for a good set of sidedrafts for sale and then go to webcamshafts.com and get a good cam, or use an l20b cam

[thisismatt]

I've been to west plains :S

[datzenmike]

You didn't say but could I guess and say you have trucks? A lighter 510/610/710 will respond to performance increases a bit better than a +- 500 pound heavier truck. Just sayn'

 

What head you have? W-53 A-87 maybe. If it isn't closed chamber you could try to hunt down one. A U-67 is open but better port sizes. You could mill it for added compression. (already has L20B can in it) Aim for a compression that you can get fuel for. No sense having 12 to 1 and paying $6 a gallon for aviation grade gas.

 

 

The stock L20B cam is basically the same as the L16SSS cam. If you go aftermarket cam you will need a bigger carb like a Weber 32/36 to make use of it. Do not over cam or over carb your engine. Too big a cam will move all the power upward in the RPM range making the motor sluggish in the range you usually drive around in. The L20B cam has a duration of 248 and a lift of .413" at the valve. For street, personally I wouldn't go above 275-290. As for lift best not to go above what the stock valves springs will handle or you will be into replacement springs and oil spray bar and the costs and wear and tear go up. Don't over do it... you will be much happier with the results.

 

Forget a header, the L18 manifold is just as good unless going total race. Install a 2" exhaust system remembering that bigger isn't always better. For an L18 2" is maximum. For the exhaust sound, you decide what you want to use for a muffler. L18 manifold with 2" exhaust pipe and maybe a turbo muffler would be a nice non restrictive system.

 

Use the money saved for a '79-'80 matchbox EI distributor, again it's more than you need for an ignition unless full race. This will give you an excellent high voltage spark and virtually no maintenance for it. I doubt this will add any power but if you add cam and carb this is the trouble free ignition you need.

 

Any engine, especially modified, deserves lots of oil to protect it. Get a high volume oil pump from any 4 cylinder WD-21 Hardbody truck '86.5-2000? This does not add power but protects your investment.

Edited October 8, 2009 by datzenmike

[1974datsun]

i have a u87 head. im not sure if its a peanut head. im thinking about saving my money to get a ca18 or sr20det. dual carbs are way too expensive for me

[datzenmike]

No such animal, must be a U-67 head. They are all open chamber.

 

You must mean a CA18ET. Not at all worth the bother. If you can't afford dual carbs you won't come anywhere near enough for a SR20DET swap. Even if you get a running motor/tranny/wire harness for EFI, you will need a high pressure fuel pump and rad. Many other things needed are custom motor/tranny mounts, drive shaft, exhaust... the list is endless and expensive even if you weld and fab your own stuff.

[1974datsun]

No such animal, must be a U-67 head. They are all open chamber.

 

You must mean a CA18ET. Not at all worth the bother. If you can't afford dual carbs you won't come anywhere near enough for a SR20DET swap. Even if you get a running motor/tranny/wire harness for EFI, you will need a high pressure fuel pump and rad. Many other things needed are custom motor/tranny mounts, drive shaft, exhaust... the list is endless and expensive even if you weld and fab your own stuff.

 

i meant a a87. what about putting a turbo on my l18?

[datzenmike]

http://forum.ratsun.net/showthread.php?t=1816

 

This is one method but requires a swap to EFI. A stock carb can be done with good results also.

 

Performance is not easy or not cheap, often it's both.

[Jesse C.]

So, let me get this straight.

 

Dual Carbs are too expensive, yet, you are willing to do an engine swap or bolt on a turbo?

 

WTF?:rolleyes:

 

First off, what have you already done to the engine, what is currently on it? Stock carb? Weber? Single Point Dist? Dizzy?

 

Just L-18 bored .50 over with an A-87 head does not cut it! What the fuck is the engine in? What do you want to do with it? Haul shit? Haul You? Chickens?

 

Tell us what you have and we can tell you what to do. Simple.

[datzenmike]

Avatar looks like a 620.

[sick620]

and im pretty sure his display name depicts the datsun he drives. lol. unless he had it in good with nissan and got him self a 720 in '74. i dont think so. :D

[1974datsun]

So, let me get this straight.

 

Dual Carbs are too expensive, yet, you are willing to do an engine swap or bolt on a turbo?

 

WTF?:rolleyes:

 

First off, what have you already done to the engine, what is currently on it? Stock carb? Weber? Single Point Dist? Dizzy?

 

Just L-18 bored .50 over with an A-87 head does not cut it! What the fuck is the engine in? What do you want to do with it? Haul shit? Haul You? Chickens?

 

Tell us what you have and we can tell you what to do. Simple.

 

it in a 1974 datsun 620. i want it to be fast. all my friends think their shitty 305's can out run my truck but i want to prove them wrong. im not sure what kind of distributor is on it.

[datzenmike]

There is no 'magic bullet' that will make an 80hp 2700 lb truck outrun a 305 chevy anything. Challenge them to an economy run.

[1974datsun]

There is no 'magic bullet' that will make an 80hp 2700 lb truck outrun a 305 chevy anything. Challenge them to an economy run.

 

but thats the reason why i want to get a ca18 for my truck

[datzenmike]

You must mean a CA18ET. Not at all worth the bother. If you can't afford dual carbs you won't come anywhere near enough for a SR20DET swap. Even if you get a running motor/tranny/wire harness for EFI, you will need a high pressure fuel pump and rad. Many other things needed are custom motor/tranny mounts, drive shaft, exhaust... the list is endless and expensive even if you weld and fab your own stuff.

 

Maybe you mean the CA18DET? About 160hp import motor? I'd swap a simple, cheap, easy to find VG30 for the same hp. Makes the same power without sweat and is a bulletproof motor. Parts everywhere unlike the CA18DET.