Datsun Roadster Forum-311s.org

Posted: **Tue Sep 19, 2023 9:28 pm**

Stumbled upon this goodness about two weeks ago through the site here, thanks guys!
Seeing as it was written many moons ago; is there anything you guys, with the experience, would change or add in regards to the Bob Sharp Manual?

Currently have the vg project on the backburner, simmering.
Not shelved; engine and trans are mounted — harness computer is not.

My 68 that was picked up a few months back has been getting the love touch. Floor pans in, engine purring, all the brakes working, all the lights work(properly). Have gone a little crazy on the polishing any and everything aluminum, brass or copper under the hood

even the distributor haha!

As the last leg of garage time for the 68 is near, I’m wondering what the wisdom on the forum would add to the manual if they could add!

Thanks Y’all!

Posted: **Wed Sep 20, 2023 1:06 pm**

It's been so long since I read that manual that I only remember it vaguely....

How much do you want to spend?

Some big improvements all around come from losing weight. Whether it's the engine or on the chassis.
Battery - smaller lighter modern battery (Odyssey?)
Alternator - smaller lighter modern (Kubota?)
Leaf springs - Carbon composite will drop a noticeable amount of weight
Shocks - Very good modern ones available
Ignition - Programmable dizzy or Crank fired ignition (affordable solutions are out there)
Header - Available headers are better than the stock manifold, but, a 4-2-1 header would be much better. Unfortunately you would have to have it built custom. If you go custom, take the time to have it reasonably specced to your engine - too big costs performance and weight penalties.
Exhaust - If it's not already, go to 1 3/4" (1600?) exhaust with good non-restrictive muffler.
Flywheel - If it's for the street, you might not want to go super light.

Engine
Oil - make sure you use a good oil with the proper ZDDP components - Oil grade is up to you, several discussion threads on the board.
Valves - A good 3-5 angle valve job and open the throat to 88-90%. Lighter valves will increase your rpm capability without having to increase spring pressure...to a point. At a certain performance level you may want to get a slightly larger exhaust valve (1600).
Pistons/Rods - The stock pieces are extremely heavy by modern standards. Modern equivalents are 1/2 the weight (part of the reason a U20 can't compete with the SR20). It is also very expensive to replace these parts with modern pieces. Lightening and prepping the stock rods according to the manual will help somewhat. Lighter rods/pistons also contribute to a smoother running engine with less stress on the bearings.
Cam - Modern grinds make a difference! Depending on your desired use spec the cam and compression ratio to work together.
Crankshaft - Removing the casting flash and smoothing the casting lines is about all I would do, other than addressing the oiling issue (if racing). I have read that lightening the crankshaft on a 4 cyl may have detrimental effects on longevity.
Vibration Damper - I'd recommend one for every engine, especially if pushing the performance level. It protects the crank, but also dampens the vibrational effects on the valvetrain.

Posted: **Wed Sep 20, 2023 8:54 pm**

Daryl Smith wrote: Wed Sep 20, 2023 1:06 pm It's been so long since I read that manual that I only remember it vaguely....

How much do you want to spend?

Some big improvements all around come from losing weight. Whether it's the engine or on the chassis.
Battery - smaller lighter modern battery (Odyssey?)
Alternator - smaller lighter modern (Kubota?)
Leaf springs - Carbon composite will drop a noticeable amount of weight
Shocks - Very good modern ones available
Ignition - Programmable dizzy or Crank fired ignition (affordable solutions are out there)
Header - Available headers are better than the stock manifold, but, a 4-2-1 header would be much better. Unfortunately you would have to have it built custom. If you go custom, take the time to have it reasonably specced to your engine - too big costs performance and weight penalties.
Exhaust - If it's not already, go to 1 3/4" (1600?) exhaust with good non-restrictive muffler.
Flywheel - If it's for the street, you might not want to go super light.

Engine
Oil - make sure you use a good oil with the proper ZDDP components - Oil grade is up to you, several discussion threads on the board.
Valves - A good 3-5 angle valve job and open the throat to 88-90%. Lighter valves will increase your rpm capability without having to increase spring pressure...to a point. At a certain performance level you may want to get a slightly larger exhaust valve (1600).
Pistons/Rods - The stock pieces are extremely heavy by modern standards. Modern equivalents are 1/2 the weight (part of the reason a U20 can't compete with the SR20). It is also very expensive to replace these parts with modern pieces. Lightening and prepping the stock rods according to the manual will help somewhat. Lighter rods/pistons also contribute to a smoother running engine with less stress on the bearings.
Cam - Modern grinds make a difference! Depending on your desired use spec the cam and compression ratio to work together.
Crankshaft - Removing the casting flash and smoothing the casting lines is about all I would do, other than addressing the oiling issue (if racing). I have read that lightening the crankshaft on a 4 cyl may have detrimental effects on longevity.
Vibration Damper - I'd recommend one for every engine, especially if pushing the performance level. It protects the crank, but also dampens the vibrational effects on the valvetrain.

Interesting, some really nice pointers I’m going to look into
I’ve seen a few Bluetooth distributors online
Haven’t thought of looking into those
But shucks I might have to; and the composite springs interesting!

Posted: **Thu Sep 21, 2023 11:58 am**

Forgot to mention:
Electric Fan - Many benefits!
- lighter than stock fan/shroud
- only on when needed, decreasing parasitic drag
- easier removal of fan/radiator - with my set up I unplug the fan, disconnect the hoses, and undo 4 bolts to remove both the fan and radiator as an assembly. The fan is bolted to the radiator bracket (engine side - puller).
- MUCH easier access to the front of the engine. Setting timing? No problem, easy to see and point the timing light. Replace the water pump? It is all exposed. Loosen the belt and get it done - no metal shroud to remove before hand.

Downsides?
You have to do some wiring (for some that's a downside....)
Someone is going to say electric fans fail....and that is true! The failure rate however is negligble. Do a search for 'failure rate of automotive electric fans' and see what you come up with....
https://www.onallcylinders.com/2012/07/ ... r-vehicle/

Posted: **Sat Sep 23, 2023 7:39 am**

Daryl Smith wrote: Thu Sep 21, 2023 11:58 am Forgot to mention:
Electric Fan - Many benefits!
- lighter than stock fan/shroud
- only on when needed, decreasing parasitic drag
- easier removal of fan/radiator - with my set up I unplug the fan, disconnect the hoses, and undo 4 bolts to remove both the fan and radiator as an assembly. The fan is bolted to the radiator bracket (engine side - puller).
- MUCH easier access to the front of the engine. Setting timing? No problem, easy to see and point the timing light. Replace the water pump? It is all exposed. Loosen the belt and get it done - no metal shroud to remove before hand.

Downsides?
You have to do some wiring (for some that's a downside....)
Someone is going to say electric fans fail....and that is true! The failure rate however is negligble. Do a search for 'failure rate of automotive electric fans' and see what you come up with....
https://www.onallcylinders.com/2012/07/ ... r-vehicle/

Interesting, I think I have one lying around, it’s a four blade
I’ll take a picture later and send it
Hmmm I might be able to do this

Posted: **Sat Sep 23, 2023 10:15 am**

Second the electric, thermostatically controlled, puller fan. Rig a cutout for hot starts with the fan nominally running.

Posted: **Sat Sep 23, 2023 10:34 am**

rwmann wrote: Sat Sep 23, 2023 10:15 am Second the electric, thermostatically controlled, puller fan. Rig a cutout for hot starts with the fan nominally running.

Ok shucks, I might have found something new to do to roadster#2 this weekend
Thanks for that

Posted: **Sat Sep 23, 2023 5:29 pm**

rwmann wrote: Sat Sep 23, 2023 10:15 am Second the electric, thermostatically controlled, puller fan. Rig a cutout for hot starts with the fan nominally running.

Does anyone have a wiring diagram for the standalone fan?
One roadster seems to have the harness for it
My other one does not
The schematic I have doesn’t show the electric fan

Posted: **Sat Sep 23, 2023 6:26 pm**

Battery +12V —> [Manual Cutout —>] Thermostatic Relay —> Fan —> Ground

Posted: **Sat Sep 23, 2023 7:32 pm**

rwmann wrote: Sat Sep 23, 2023 6:26 pm Battery +12V —> [Manual Cutout —>] Thermostatic Relay —> Fan —> Ground

Thanks for that

greatly appreciated
On the four blade I have it has a plug
Should I just cut the plug and wire it up as describe above?

Posted: **Sat Sep 23, 2023 8:40 pm**

If you have the mating plug, you can retain what you have, or replace the plug with a set of mating plugs, or cut the plug and butt splice the wiring per the above.

Posted: **Sat Sep 23, 2023 11:37 pm**

rwmann wrote: Sat Sep 23, 2023 8:40 pm If you have the mating plug, you can retain what you have, or replace the plug with a set of mating plugs, or cut the plug and butt splice the wiring per the above.

Well the 4 blade fan has the plug (wish I would have taken a picture earlier) the roadster I would/could put it on doesn’t seem to have any spare/additional wiring

Come to think of it; the red roadster(donor for this part) had the plug in its wiring harness
Should I just cut the harness and pull the plug and wires out?

Would I then run the wires (mated plugs) on the recipient roadster as described previously?

Eventually the red roadster will be running vg30 factory comp and harness

Not going to lie, pretty novice with this stuff
Apologize if my question(s) are lowIQ
I sincerely appreciate any advice / direction

Posted: **Sun Sep 24, 2023 8:05 am**

There was no roadster wiring harness for an electric fan, and you don’t want to use the existing thermostat wiring for this purpose, so you are adding a complete separate assembly of power, electronic thermostat, [cutout switch], fan and ground leads, as efficiently and neatly as you can.

I mounted the electronic thermostat temperature sensor lead dry, to the radiator header tank, but it could be mounted wet, within the radiator supply (top) tube.

Posted: **Sun Sep 24, 2023 12:47 pm**

As rwmann says you have to run a complete wiring circuit for the electric fan. No roadster came with an electric fan or any wiring to accommodate it.
Here is a wiring diagram from Motor Trend. The Temperature switch is used to ground the circuit and switch on the relay. It has 2 positive 12v supplies.
1st is the power for the fan, which can be in the double digit amperage, and 2nd is switched power that comes on with the ignition for the switching cct.
https://www.motortrend.com/how-to/how-t ... h-a-relay/

Please also ensure you have a large enough wire for the amperage draw of the fan.
https://www.google.ca/search?q=amperage ... nt=gws-wiz

Don't ever worry about the questions, we all started not knowing. Some learned earlier and more than others. Some are still learning after many years (me). Change is a constant, we all have different ways of learning and retaining information. It is a privilege to pass on some information without judgement or recompense. Perhaps, in time, you will be able to do the same.

Posted: **Sun Sep 24, 2023 8:28 pm**

Daryl Smith wrote: Sun Sep 24, 2023 12:47 pm As rwmann says you have to run a complete wiring circuit for the electric fan. No roadster came with an electric fan or any wiring to accommodate it.
Here is a wiring diagram from Motor Trend. The Temperature switch is used to ground the circuit and switch on the relay. It has 2 positive 12v supplies.
1st is the power for the fan, which can be in the double digit amperage, and 2nd is switched power that comes on with the ignition for the switching cct.
https://www.motortrend.com/how-to/how-t ... h-a-relay/

Please also ensure you have a large enough wire for the amperage draw of the fan.
https://www.google.ca/search?q=amperage ... nt=gws-wiz

Don't ever worry about the questions, we all started not knowing. Some learned earlier and more than others. Some are still learning after many years (me). Change is a constant, we all have different ways of learning and retaining information. It is a privilege to pass on some information without judgement or recompense. Perhaps, in time, you will be able to do the same.

Thank you for the additional information and links, much appreciated! I hope to one day gain the knowledge and be able to pass it on to my children; who are 3 and 1 now!
My three year old loves “fixing” the roadster with me. The 1 year old wants to join in but wants to swing the tools at the moment haha!

Was going to start figuring up the fan today—previously ran all the fuel lines got everything hooked up, waited until today to get gas and coolant and fire it up after everything had been gone over etc. Up to this point we had been using a gas jug with the lines running from and to it. Well, gas tank has 3 decent holes; gas was justa running

So todays plans were pushed back, however on a positive note I have some additional materials now before I jump into it!

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