1963 AP5's dirty old '82 Sigma SE

[1963 AP5]

Please share your comments

[oldrx7]

Two tone is sweet! 

[Valiant]

Slant six power to come?

[MaxPower]

Thanks for the springs help, are they sitting right in that pic thou? 

[bigfoot]

1 minute ago, 1963 AP5 said:

If anybody knows where I might find an inlet manifold for a RWD SOHC Mitsubishi 4G63 engine please let me know.

I will need one to hack about (modify) in order to make this work.

Injected or carb? I'm keen on the weber setup if you get rid of it

[1963 AP5]

I'm trying to keep things as simple as possible so I am planning on building a draw through set up using the Weber.

[RUNAMUCK]

I spy an sc14 from an estima Van!

[RUNAMUCK]

Also if your engine is 2000cc, please run the blower at 1:1 ratio.

I assume you're sticking with the carb? If so, Please go drawthrough. 

I ran a 32/36 for a while on an SC14. But I found a 350cfm Holley used truckloads less gas.

[JustHarry]

There is a manifold on. 4g63 in a l300 at my house that belongs to @DoBro Jesus 

In chch though

[1963 AP5]

On 06/04/2021 at 18:01, RUNAMUCK said:

Also if your engine is 2000cc, please run the blower at 1:1 ratio.

I assume you're sticking with the carb? If so, Please go drawthrough. 

I ran a 32/36 for a while on an SC14. But I found a 350cfm Holley used truckloads less gas.

Thanks

Yep I am planning on doing a draw through set up using the 32/36 that I already have. I am pretty sure that the Holley would be better for this application but I have the Weber so I will give it a try. I am assuming you set up your Holley with an externally referenced power valve.

It is a 2000cc so I will start with a 1:1 ratio.

[RUNAMUCK]

Yes, yes it was. 

The power valve set up is probably what made it so good on gas.

[1963 AP5]

I have yet to properly investigate the power valve set up on the Weber but I expect the principle is similar to the Holley. I believe it lives under the top plate and maybe it can be tuned or modified to work with the van supercharger. We will see I guess.......

[RUNAMUCK]

Theres a port in the underside of the power valve chamber which takes its signal from a hole in the base plate. You plug this up. (My book said to use lead shot, but I say fuck that! Better off locktiting in a tiny grub screw imho.*

*tbh, I can remember how big that hole was, so that might not fly. 

Then you cross drill a hole through the side of the base plate (theres a black boss cast in for this) on an angle to intersect the feed up to the power valve chamber.  Add a wee hose tail to this new port, and run a feed from after the supercharger. 

The rule of thumb for powervqlve selection (iirc) is half your idle vacuum figure.

But my engine made boost so furiously with even the lightest touch of the pedal than I ran a 2.0" valve. It stayed shut untill the vacuum fell below 2". But even driving like a total bitch it was next to impossible not to have the vacuum fall to zero or below.  (Obviously below zero is into boost)

[RUNAMUCK]

Yes yes yes!

Most excellent progress Bevan!

Did I mention Holley accelatator pump nozzle dribble earlier? 

If not we can save that chT for once it's running.

[Valiant]

Very cool.

I really like your intake manifold, and the use of a lay shaft im looking forward to seeing how that progresses.

My only complaint is that carb flange. It's not for an Impco gas carb, which would be fantastic in my opinion. Imagine supping that high octane low price goodness.

[RUNAMUCK]

My 2c,

Make sure you have lots of bracing from the block to the supercharger. The torsional load of driving the blower will put serious strain on your manifold mounting.

[RUNAMUCK]

Does the "carb" have provision to run a post supercharger signal to its map sensor? 

[RUNAMUCK]

@1963 AP5

Have you given it wide open throttle yet? You wont see the peak boost figure without having the holes wide open so the blower can move its maximum volume of air per revolution. 

I would have thought 5psi was a bit low if you're running 1:1 atm.

Running 1:1 on a 1500cc donk I made 11.  Unless your motor has some really crisp flow characteristics, I would have expected a number closer to 7.

[1963 AP5]

Yep I have certainly run it at WOT.

I have my doubts about the accuracy of the gauge, you can see in the picture below that it doesn’t sit at zero without the engine running so it is probably under reading by a couple of pounds.

The real number could easily be closer to 7.

[CUL8R]

Well done, sounds even better with the wide belt too!

Im impressed its running that smoothly straight off the bat! Have heard varying stories about how easy they are or aren't. Id say most is operator error tbh