403 LS2 FD - LS7 Build for 2020!

[MPbdy]

Honestly I do not have a clue.  From pictures it looks like there is a slight taper down to the center of the piston.  Not a dish really, just a concave top with valve reliefs.  Their kit uses different manufacturers than they used to though, so the pistons that are coming may be different than that. 

Whatever comes I know I can make work.  An 18cc dish...that would not have worked.  I want the smallest amount of relief as possible so the quench stays tight.  With a big dish you gain a ton of quench area.

[Sabre002]

Well what is the comp ratio you are looking for?  Also what is the combustion chamber volume on your heads.   Whats the thickness of the head gasket? 

[MPbdy]

11:1.  I don't think the 91 octane out here can handle much more than that.

70cc at the moment

Stock mls gasket, I think .051 compressed?

[Sabre002]

Whats the bore?

If you have a place you can get Fuel with out 10% ethanol in it you should.  I lost my last place that cant get that for me so I'm thinking about decking my heads and building a race gas only motor. 

[MPbdy]

4 inch bore that will be honed as soon as I can measure the pistons.  It will be in the .005 to .010 range probably.

I must be out of the loop on this one, whats wrong with E10?  There has been a good % of ethanol in pump gas for a long time now.  What is so horrible about it that you will convert your engine to race gas 

[mattster03]

hey daniel.  side-tracking to your differential work... I am in the process of moving my MT companion flange to my AT diff; do I need to replace the pinion crush sleeve and oil seal (i am not planning on replacing the pinion bearing)? Also, I feel like I need three hands to set the ring gear assembly back in the housing with the bearing races not slipping off... what's the trick?

[MPbdy]

I would definitely replace the crush sleeve any time you loosen the pinion.  An oil seal and crush sleeve are cheap, like $25 shipped cheap.  It is a pretty big gamble if you don't replace the crush sleeve since it will wipe out your bearings.  Make sure you have a long ass wrench to tighten the pinion nut, and an inch pound torque wrench, preferably with a dial.

You are setting your bearing preload by compressing the sleeve a little bit at a time.  You crush it for a long time before the bearings start to drag, and then you go a little at a time.  As you compress it more, the pinion rides against the bearings harder and creates more drag.  You measure the drag with the torque wrench and get it to spec.  If you go too far, you've got to start over.

The easiest way to do it is with 3 hands lol.  The next best way is to put the two races on the bearings and hold the carrier by the races.  Rest one of the shims inside the case, and then slide the carrier in and hope it all stays together.  Then you can take a rubber mallet and knock the other shim into place. 

[frijolee]

Hey Daniel,
 
Where are you at in SoCal?  I assume you'll come out to SevenStock?  Car's looking great!
 
-Joel

[Sabre002]

4 inch bore that will be honed as soon as I can measure the pistons.  It will be in the .005 to .010 range probably.

I must be out of the loop on this one, whats wrong with E10?  There has been a good % of ethanol in pump gas for a long time now.  What is so horrible about it that you will convert your engine to race gas 

The power and compression ratio I'm working with does not leave much room for error.  I'm fear full of spark knock and pre detonation.  the 10% ethanol just adds to the possibility of that.  Also my car will be a road race time attack car I don't want to run into that problem being magnified at the track due to heat soak.  It was 100 degs this summer for like 60 days.  So If I'm to close to that threshold already I mine as well just bump up to race gas.  Its just something I have kept in my head that I might be forced to do. 

[MPbdy]

Thanks!

I went to sevenstock last year.  I may come out again for a little while.  It was really damn hot last year rofl.  I felt like I had seen it all after being there a couple hours.

I'm in Rancho Cucamonga, five miles from AAA speedway   I definitely want to meet the socal gang at some point.  Last year I talked with Mark (gnx7) while looking at Mike's car, and he told me to replace the pillowball bushings haha.  My dad and I talked with Dan for a few minutes too.  I never really introduced myself though.  We saw Mike and the ls7 car (is Ray the owner?) but didn't meet them.  I looked high and low for your FC but I couldn't find you   I really wanted to see it.

I know Marcus wants his car done for sevenstock...I hope he gets there.  If he gets it done I'll probably come for a little while.  I wish I could say the same about my car...maybe next year haha.  I've kind of stalled recently between the heat and finding stuff wrong on everything I touch.

[MPbdy]

4 inch bore that will be honed as soon as I can measure the pistons.  It will be in the .005 to .010 range probably.

I must be out of the loop on this one, whats wrong with E10?  There has been a good % of ethanol in pump gas for a long time now.  What is so horrible about it that you will convert your engine to race gas 

The power and compression ratio I'm working with does not leave much room for error.  I'm fear full of spark knock and pre detonation.  the 10% ethanol just adds to the possibility of that.  Also my car will be a road race time attack car I don't want to run into that problem being magnified at the track due to heat soak.  It was 100 degs this summer for like 60 days.  So If I'm to close to that threshold already I mine as well just bump up to race gas.  Its just something I have kept in my head that I might be forced to do.

Yeah that makes sense.  In California we've just got to work with the piss they give us.  In your case it makes sense to go to race gas.  I'd sooner DD my car when its done then turn it into a race car at this point.  My engine is going to make "bad" peak power numbers...well in the range of cam only ls2 setups.  The power curve is going to be pretty nuts though.  It should be a great street engine, which is the main goal.

With 10.9 or 11:1 the engine will be easy enough to tune to run on 91, even if its e10.  The LSA cylinder heads have a really good combustion chamber design.  It should safely take quite a bit more spark timing than a 243 or L92 head.  In my case we'll probably step the timing back a degree or two and richen it slightly from peak power and call it a day.

Do you have HP tuners?  It would be interesting to find out if you're making the best power right on that threshold.  Sometimes you can step it back a degree or two and make the same power.

[Sabre002]

No I do not have HP tuners.  I"m not good enough at that yet, so I pay for a tune.  I'm going to have Speed Fab do that on my car.  I'm looking to have 11.3:1 or a little more out of it.   I will be using a really ported 853 head or swaping to something else if I dont make the power I want. 

[MPbdy]

Well the fuel system is as done as it can be right now.  I still haven't found a fuel pump tree.

I replaced all the old rubber lines with new EFI hose.  The rotary fuel injection ran at 40 psi, and the ls engines run at 58 psi.  I don't know if the old lines were rated to 58psi.  They were also 15 years old.  Its pretty cheap insurance to replace them now...especially since you can't get to any of it with the suspension in the car.

Here is the corvette FPR and some parts from the GTO.  Parting out a whole car is nice when it comes to these kinds of things.  You can recycle parts instead of getting nickel and dimed so bad.  For those that don't know, the corvette FPR is a fuel filter and regulator in one.  It regulates to 58 psi and bypasses the excess back to the tank.



I'm using the stock fuel filter mount to build the new setup around.  The regulator fits perfectly, and everything is rubber isolated.  If Mazda felt the need to rubber isolate this stuff its probably a good idea to keep it that way.  It probably could transmit a lot of noise into the car with fuel going through it.



Here it is in the car.  This completes the fuel lines from the tank to the engine bay.  I just need a fuel tank in the car and something in the engine bay to hook lines to and it will be complete.  What's nice about this setup is you can bypass fuel right at the tank so you only need high pressure feed running up to the engine bay. 

Don't yell at me.  Those are not hose clamps.



Here the charcoal canister is back in place.  The tank feeds vapor to the canister, and the canister feeds one of the hard lines going up to the engine bay.  That hardline then connects to the intake so the gas vapors don't kill babies and flowers and stuff. 

The mazda has a much simpler evap system compared to newer cars.  The mazda canister vents to atmosphere all the time.  The engine still sucks the vapor from the tank, but it never completely seals.

I'm going to hook the bottom vent on the canister to the now unused hardline going up to the engine bay.  The middle line used to be the bypass from the rotary fuel rail.  Up in the engine bay somewhere I will hook up the purge solonoid for the canister that I got from the GTO.  With the solenoid hooked up, the engine should pull vacuum on the tank and everything should work great.  I will just need to drill a hole for the vacuum sensor from the GTO and wire it up to make the computer happy.

I think I will be able to pass smog with this setup.  A hardass ref will want the GTO canister in the car.  I hope they will see the effort that went into making it work and allow it.



Holy crap its back in the car!

[Steve]

Hey Dan how are you going to pass the sniffer with the motor work? Im conteplating a ls2 now because ls6 carries a premium.. your stroker Idea sounds great but Im worried that theyre no going to notice if its modded???

[MPbdy]

Its going to pass because of a tiny tiny camshaft   210/218 on 116 with .560 and .558 lift or something.  Its also on the GM lobe profiles.  The stock ls7 cam is 210/230...but that is way too much of a split.  This cam is an ls7 intake lobe and the bigger ls6 exhaust lobe on stock lsa.

With lots of overlap your hydrocarbons go through the roof.  I think people have passed smog with the right 224/224 cam, but its all about overlap.

The next issue you can run into is NOX emissions.  NOX goes up with power.  More power, hotter combustion, more NOX.  There isn't really a way to get around that, but I should be no where near that point at this power level.

There is no way to tell from the outside that the engine is actually a 6.6 instead of a 6.0.  Except for the rotating assembly, every part I'm using is OEM. 

Like I've said before, it definitely won't be the fastest stroker ever, but I've not read about any that are able to pass smog.  However, a 400rwhp cam only ls2 vs this thing should be a night and day difference.