Re: Type 1 twin screw supercharger build / 9 yrs later I'm back at it

[Clonebug]

E85 allows for a higher compression ratio along with higher advance on ignition. What it will be is engine specific and dependent on your boosted IAT's.
I think 9.0:1 should be ok if you start out low on your ignition advance and work your way up.
The only issue I see is with a blower your low to mid range torque is going to be high resulting in high cylinder pressures in the 2500-3500 rpm range which could give you detonation issues if you are not careful.
Take it slow and listen carefully to your engine.....a good muffler is a wise idea when working through a tune.

[Piledriver]

If you are sure you wont be using anything but e85, or at least e70+, does your blower have a bypass valve you could engage if you it proved a necessity to give it a gallon or 2 of gasoline? The Eatons usually seem to have one built in.

[Alexander_Monday]

If you are sure you wont be using anything but e85, or at least e70+, does your blower have a bypass valve you could engage if you it proved a necessity to give it a gallon or 2 of gasoline? The Eatons usually seem to have one built in.

Pump E85 has been readily available many places here for many years.
The most consistent pump E85 is a few miles away from me and runs 77 / 78% consistently for summer blend.
The last fill up I did drop some, I assume due to winter blend, but it was mixed with the 77% in the tank so I don't know the %.
I have the GM ethanol sensor tied into MS3X in the return line.
It is all I plan on using, this is a fair-weather weekend warrior car not an everyday driver.

I am trying to get the local race fuel supplier to get Sunco E85 race fuel in 55-gallon barrels, but there isn't much call for it here.
The reason being that I have the E85 black goo build up from the injector spray onward in the intake tract.
The fuel lines etc. are free of any buildup as others have reported.
It is a hit and miss phenomenon that has to do with additives and the amount of overlap so affects some regions and not others.

I have a Procharger bypass plumbed between the plenum after the intercooler and the plenum after the throttle body.
It has a vacuum line from the plenum after the intercooler to sense engine vacuum / boost.
When engine vacuum is below (stronger) than 85 KPa the valve opens.
So no way to keep it open without a vacuum source.

I could certainly set up MS3X to really retard the ignition below a certain % and give me a big fat warning on the dashboard.

[Alexander_Monday]

E85 allows for a higher compression ratio along with higher advance on ignition. What it will be is engine specific and dependent on your boosted IAT's.
I think 9.0:1 should be ok if you start out low on your ignition advance and work your way up.
The only issue I see is with a blower your low to mid range torque is going to be high resulting in high cylinder pressures in the 2500-3500 rpm range which could give you detonation issues if you are not careful.
Take it slow and listen carefully to your engine.....a good muffler is a wise idea when working through a tune.

I have dual Borla ProX S mufflers so it is pretty quiet.
I don't want to draw any more attention from the police than necessary.

[Alexander_Monday]

The cam finally arrived.
This is what Mike Jones spec'ed for my 2110 supercharged.
Will have to see how it does with the 2387 supercharged.
It has 4 degrees of advance ground into it.
Less exhaust lift, but more exhaust duration than intake.
I am going to chart the profile and see how it compares to a couple of Engle profiles for area under the curve.

Hopefully there won't be a lobe clearance issue, but CB hasn't shipped my stuff yet.
I will also have to see how much clearancing there will need to be between the lobes.

Any advice on procedure to clearance?
It is an EP12 blank which I read is hardened cast iron.
I know from cutting hardened cast iron on my mill that it is not easy and doesn't like to make chips, but more like dust.
If I do it by hand I am worried about damaging a lobe or bearing surface.
My Daddy always said I was a disaster waiting to happen.

20250118_182934.jpg

[Piledriver]

You should break the edges by hand with a diamond hone or even diamond files or diamond sandpaper...
If it needs deep grinding for clearance I'd find a pro to do it.

[Alexander_Monday]

What grit or range of grits?

[Alexander_Monday]

Didn't get a lot done this weekend.
I did get the ring gaps set at the recommend .018" top & .020" 2nd and checked the oil scrapers for .010" minimum.
Checked the cylinders for bore and roundness.
CB did a really good job of honing them, all within .0003" spread checked 3 ways at 3 depths.
Calculated average piston to wall clearance of .00225"

However, the labeled piston weights from Wiseco are off.
I have 2 that are 389.7g & 389.5g.
And 2 that are 388.7g & 386.8g.
I can pair them up since it is a boxer engine, but 1.9g is a lot to remove for the oddball pair..
Not sure where would be best.
Here is a chunk of aluminum the width of the walls from the pin to the skirts that weighs 1.9g.
Perhaps a 1/4 from each wall?
Don't think I want to take any from the pin areas?

20250119_144824.jpg

A pic from above:

20250119_150551.jpg

[Piledriver]

What grit or range of grits?

Grit ~ doesn't matter, the goal is to knock off the super hard nitride at the lobe edges so it doesn't get knocked off while running and go through your oil system or dig into a lifter. It concentrates at the sharp edges, very close to diamond hardness.

Coarse faster than fine.

May only matter for nitrided cams. I don't know if the one you have is nitrided. Won't use anything else, personally, lost 2 motor builds in a row from non-nitrided " highly regarded brand name" cams many moons ago, sucked.

Still suspect sharp edges will be harder and more liable to dig in/chip off.

Recently invested in two sets of Thorstens tool steel t1 lifters and T4 lifter bore inserts... Have a set of Schubek SiN lifters I'm hesitant to use as they have the glued on SiN puck.

[Clonebug]

You should really work on getting your idle and cruise VE close before going into boost. Your tune is important in that all your cold start and accell settings are based on a percentage of your idle and cruise......and somewhat possibly into your boost zone.
Once your cruise area is set you can estimate how much more fuel to give it in boost without running pig rich......Running pig rich will make your engine do a hard hesitation going into boost......I've had it happen before.

[Alexander_Monday]

I will be starting over, but with the knowledge I have gained tuning the 2110.
Starting with my largest supercharger pulley: 1st idle, 2nd cruise, 4th cold enrichment, 3rd acceleration enrichment (With MAF AE is negligible), then boost, then reiterate with a progression of smaller pulleys.
I am using MAF instead of speed density so fueling is mainly a process of adjusting the MAF curve and fine tuning the MAF % correction table (VE1).
VE1 doesn't vary nearly as much with MAF, less than 10% if the MAF curve is close because it isn't a VE table.
Variations generally correlate with load more than with RPM.
However, due to the change in engine stroke and bore, compression ratio (Going to bump up from 8 to 9.2 to 1), MAF, injectors, and intake I will be starting fresh.
I will be using a 93 Cobra MAF (Ford X3Z ECU transfer curve) instead of the 95 Cobra MAF because I almost maxed out the 95 Cobra MAF with the 2110 at 4.97V.
The 93 MAF will be about 4.45V at the same air flow as the 95 was at 4.97V
I saw a max duty cycle of 85.3% (although it was a little rich) with the 2110 850cc injectors so I purchased ID 1050cc injectors to use.
I am considering adding secondary plenums closer to the heads than the main plenum and injecting there instead of right above the head to change the resonance of the intake and improve fuel atomization.
I am going to add ducting to get the air intake further from the engine.

Edit, : Lol forgot to mention another big change, the cam.

[Alexander_Monday]

You should break the edges by hand with a diamond hone or even diamond files or diamond sandpaper...
If it needs deep grinding for clearance I'd find a pro to do it.

Like so?

20250126_151855.jpg

[Alexander_Monday]

Got the pistons balanced into sets today.

20250126_114044.jpg

20250126_114103.jpg

20250126_152614.jpg

20250126_152655.jpg

[Piledriver]

Looks about right.

[Alexander_Monday]

Didn't feel good this weekend so didn't get anything done out in the shop.
Since I am going to "cam doctor" this cam I did take all the dimensions and made an EP12 cam blank in CAD.
I'll CAD a "cam doctor" using the cam blank as a reference.
I have a spare 2000p optical encoder and a dial indicator with data output to incorporate into it.

VW Type 1 Camshaft Blank.gif