My '59 Enfield /Indian 750cc Chief High Compression Build

[Scottie J]

Those of you running an Aisin, did you install any kind of intercooler?

[Nortonist 592]

I'm still in the early stages of installing my Aisin.  There will be a long inlet tract from the blower to the head.  I plan an intercooler along the line.  But its still in the  thinking stage.  I may come up with something better than I have in mind.

[generatorshovel]

I can start out with 180 degrees water temp, and after a test run of 2 x 1/2 mile flogs and return with a cool engine, not registering on the temp gauge 
Using methanol with a draw thru aisin setup seems to be fine without an intercooler 
http://youtu.be/Gppco3aKYe0
Tiny

[thefrenchowl]

As a rule,

No intercooler with methanol
Intercooler with gasoline

Patrick

[Briz]

You really dont want an intercooler on a draw-thru setup. At all. With any fuel.
Its basically a bomb!
One backfire and BOOM!

[Scottie J]

Page 11 everyone says I have to worry about air charge temps.  Page 12 everyone is saying I don't need an intercooler?   

[SPARKY]

What they are trying to tell you is with a draw through--NO it is an air fuel bomb---with efi or blow through yes!!

[Scottie J]

I do plan on running an aftermarket EFI system.  Should I still stay away from an intercooler?

[DaveB]

I have done a little more reading and number crunching on blowers and there effect on intake air temperature. The increase in air temperatures bears out in practice as well as thermodynamically. Is it enough of an increase to warrant an intercooler? That's the beauty of all the experienced builders on this site. Based on your specific build and their experience, you can get a good idea.

On the topic of using methanol as a fuel. It will typically result in lower intake temperatures when compared to gasoline. Two of the experienced racers here have implied this. The properties of methanol vs gasoline bear this out. When fuel goes thru the carburetor or fuel injection it must change from liquid to gaseous state; evaporation. When this change of state happens thermal energy is absorbed. The amount absorbed is called the "latent heat of vaporization". This well established attribute is far higher for methanol than it is for gasoline meaning methanol absorbs more heat than gas when it evaporates. Generally, even with a blower the intake air temperature is lower with methanol than gasoline. There is a paper on methanol as fuel here: http://web.anl.gov/PCS/acsfuel/preprint%20archive/Files/20_2_PHILADELPHIA_04-75_0059.pdf . If you add nitromethane to your methanol this and other things change.

One caution when using methanol is, a methanol fire is virtually invisible compared to a gasoline fire that you can see.

I have hear how bad using a blower with pull thru carbonation or fuel injection is. I think I understand why but would like to see if my explanation is correct. All the air after the carburetor or fuel injection now is mixed with fuel and is explosive. If we put a blower and intercooler after fuel mixing we have a considerable volume of pressurized air/fuel mix heading for the engine. A backfire would ignite this and possibly rupture something like the intercooler. Also while the blower wound down it would keep making air fuel mix, that is on fire.

[Sumner]

I do plan on running an aftermarket EFI system.  Should I still stay away from an intercooler?

If the EFI throttle body is on the pressure side along with the injectors then run the intercooler between the blower and the throttle body.  I looked at images....

https://www.google.com/search?q=Aisin+Model+AMR500&safe=off&client=firefox-a&hs=bRk&rls=org.mozilla:en-US:official&source=lnms&tbm=isch&sa=X&ei=J1LhUqSdGJP7yAGk8oCYCQ&ved=0CAkQ_AUoAQ&biw=1143&bih=668&dpr=0.9#imgdii=_

and if this ....



..... is it then I'd think doing the above would work fine.  So where are your injectors going to be?  I'm pretty much on the turbo bandwagon for B'ville but it looks like an interesting supercharger (I'd still go the turbo route myself though  ),

Sum

[Koncretekid]

Scottie,
Just remember, you don't have to build the next world's fastest Indian in one year.  I started studying the supercharging thing, which led to the electronic fuel injection thing, which quickly led to "information overload".  Maybe your 35 year old brain is quicker than mine, but the more I study these subjects, the less I seem to know! 

I think the ultimate supercharged motor is going to be a blow thru system with EFI, an intercooler, and an engine management system like Megasquirt which can monitor and control the EFI.  But I don't plan to jump in with both feet at once.  If I can give you just a bit of advice (please don't think I'm trying to dissuade you), it would be to build the bike using the best components you can afford, set it up for Bonneville, take it to the flats with a cart load of spare parts, sprockets, and jets, and see what it will do. Bring a camera and take about a million pictures of other bikes, then set about planning the ultimate machine.  This is basically what I have done, and now after 5 years, I'm almost ready to try EFI, then supercharging.
Tom
P.S. I will be in Lafayette, Colorado from March 15th until the end of May, so keep in touch and maybe I can come down and give you a hand.

[generatorshovel]

Some of the problems Iv'e had using a draw thru system include, borderline excessive vacuum between the blower and carb (20"), resulting in difficulty jetting correctly maintaining a clean transition from pilot, to needle jet.
Although I've had a few backfires with the BOV earning its keep (not good for the pulse rate) they usually occur during startup.
Don't expect to use the same carb jetting/carb that worked fine before adding the supercharger, blowers write their own tuning rules, 2 years, and I'm still learning.
I'm trying a wideband 02 gauge to help me get things right, but after several startup, run, test and tune rides, totaling 1 hr in total, the condensation methanol makes in the exhaust while the engine gets to operating temp has killed my sensor, even though I took every precaution to avoid this problem, which could be an on going expense if you use efi and methanol , but I feel this is the way to go.
Hey, its all FUN ! , 60 years young and still learning,,,,,
Tiny

[Sumner]

.....I'm trying a wideband 02 gauge to help me get things right, but after several startup, run, test and tune rides, totaling 1 hr in total, the condensation methanol makes in the exhaust while the engine gets to operating temp has killed my sensor, even though I took every precaution to avoid this problem, ...

We are using Innovate's....



http://www.amazon.com/Innovate-Motorsports-3729-Heat-Sink-Extender/dp/B000CO9MFI


....stand-off heatsinks with the stude with the turbo and they have worked well on gas.  I assume you have them in the top of the pipe?   You could maybe make a siphon standoff like Innovate's that had some sort of shut-off possibly.  Warm the engine with it shut-off and then open it.

Hooley has tried the O2 sensors on his drag car running alcohol with mixed results, mostly negative I think but I don't think the sensors went bad necessarily.  I'd have to talk to him or see if he reply's here but do know people use them with alcohol.

With EFI and such now available and supported I'd think I'd just bite the bullet and go with a blow-thru from the beginning.  Draw thru seems simpler at first but as you've pointed out that isn't always the case when all is said and done,

Sum

[SPARKY]

SJ  Kon---kid is giving straight UP straight advise--pls heed it--  you need to make this a journey---it can be a LONG pleasant one or a short one. What he is trying to say you need to embrace the learning curve.  B'ville is DIFFERENT and a lot of really smart folks have failed in their quest and a lot of "dumb" folks have earned a PHD in Salt Flat Racing and have the records to show for it.
 The secrete is STUDY, study, Study, learn, learn,learn, When you do all of these, you will be able to walk up to most cars, trucks, or bikes out there and you will have a clue what the builder was trying to do,, a lot of us who some may think,  hold phd's -- they see themselves as still in salt flat kindergarten 

Kk is right --baby steps--- get the seat time build a good NA eng, get a good idea just how FAR you have to go---but as the old saying goes all GREAT Journeys begin with the first step---enjoy & savor this possible great journey you have undertaken

[thefrenchowl]

Hi, I'm a bit confused now...

EFI, O2 sensors, the lot as found in modern cars, isn't that just so that you can run gasoline at the best level?

Since methanol is a lot more forgiving as for AF ratios, can't a single simple carb be the answer?

I must admit to really hating modern engines and their technology, lean, EPA and the reults, all this electronickery that's supposed to be better...

Better for the environment, I have no doubts, but better for racing, I have my doubts!!!

As for the learning curve and taking things easy and steady, it all depends how far away one lives from the Salt Flats... I'm coming from GB, I can't afford 10 years of steadyness before being in a position to beat my goals!!! So I went for broke at the 1st visit...

And as for supercharging completly screwing up the supposedly unmoveable AF ratios, I can vouch for that... My calcs were giving me .8 to 1 liter of methanol used per mn on the salt flats, 2.5 times gas usage, I'm now at 2 liters per mn and my main man, used to alky on his little Cooper racers here in GB, tells me we're still a touch on the lean side of things...

Patrick