403 LS2 FD - LS7 Build for 2020!

[kinger]

Holy hell that is a cam!! Racecah!  Love it!  5000+ RPM in that thing will be stupid, absurd, craziness!  Did I say I love it yet? 

[MPbdy]

You got it!  The goal is to make 5800-7800 pull like a mofo.  Shift recovery is around 5800 rpm.  So long as it is driveable, this car doesn't need any more power below 5000 rpm lol.

Finally the pictures!

So the big point of stress for a lot of people with LS7's right now is the titanium rods.  The CRN coating for whatever reason is getting chipped away on the rod faces and putting titanium powder through the oil.  The failure mode is still excessive heat and a spun bearing, but also sucks that you're pumping titanium grit through your engine as well.

I was very pleased with the condition of the rods coming out of the shortblock.  Most of them looked pretty much virgin, and a few had some witness marks - but nothing that even closely resembles a coating failure.





The crank was also in good shape with no visible signs of wear or damage.  It has since been mag'ed, checked for straightness, and polished with a clean bill of health.



The block did have a couple bores with some grooves that actually needed to be cut out.  Nothing major, but it looks like some junk made its way through the engine for sure.



Same as the bores, the bearings had a little bit of crud in them.  Probably what all of these things look like coming apart.



One surprise tool purchase I needed to make was a main cap puller for the LS7 block.  I highly recommend this thing.  Here's my dad modeling it lmao.  The LS7 has billet steel main caps and have dowel bushings for alignment.  They do not come off easily unless you have the right tool.

[MPbdy]

This was kind of crazy lol, but we drilled and tapped the block for oil squirters.  With the plan to be running high compression with sometimes questionable octane fuel, and also hopefully run road race and full mile events, I wanted to help this thing out as much as possible.

Also with the dry sump I want to run some serious crankcase vacuum.  It is a concern to run high vacuum as you lose the splash oiling on the pins and you might wind up welding a pin to the rod and throwing it out the block.

This was a nice kit, but rather sketchy lol.  Thankfully...no harm no foul and the block is drilled and tapped for 8 squirters.







The hole is drilled into the main journal for oil feed, and an oil squirter jet is screwed into there.  It protrudes through the other side of the web, and the angle of the jet makes it spray the underside of the piston.  It cools the entire underside of the piston as it goes up and down the oil crosses back and forth.


So this was the final step needed before sending the block out to machining.  Didn't exactly want to have the block machined and then break a tap off in the main web or something stupid....

We use Dougan's Race Engines in Socal for our race engines.  These guys are CRUSHING it in trophy truck races right now.  They pretty much have booked themselves solid with their own race engine program and have turned away outside work.  Luckily my dad was able to call them up and they agreed to keep doing our race engines.  These guys are the ones out front coming 1, 2, and 3 every event.

http://dougansracing.com/

Machine work wasn't too serious.  We had them clip the deck to true it up, honed the bores to the new pistons, and they needed to hone the rods to fit the new pins.  When I torqued the ARP bolts in the rods they didn't distort so the big end did not need to be machined.  The mains were also true and did not need an align hone.

Everything is done with machining and we've started with mock up.  Once everything checks out the rotating assembly can go out for balance.

[MPbdy]

I started mocking up the block the last couple weekends.  I am pushing to get to the point of checking valve drop so I know my piston to valve clearance.  That will tell me if 1, the cam fits, and 2, if I can cut the heads another .060" to bring the compression up where I want it.  I may be able to flycut the pistons if I need a little more clearance, but we'll see.  I have a nice engineering contact at Mahle that will probably answer me if I write to him.

I went a little crazy after I ordered the pistons...a small dome would've made things easier, but I got these for an absolute steal on eBay with one of those $100 rebate offers that were going on, and the pistons were already marked under summit pricing.  A more race/custom oriented piston would've been triple the price, and I love the quality of Mahle parts.  They make it very apparent why they're a top tier 1 supplier to the auto manufacturers.

I got a little stuck right before the moment of truth and haven't been able to get my answer yet regarding PTV.

So like I mentioned before, Billy Godbold is a G and posted on his facebook (if you aren't friends and follow him, you should...you see some cool ass shit) about some prototype low shock solid roller lobes that he's developed recently.  I reached out to him and he sent me his unpublished lobe lift and let me grind my cam from them. 

These low shock solid lobes have slightly more lash than a LLSR which has some definite benefits.  These lobes according to Billy have a "wider range of acceptable lash" meaning the cold setting isn't as critical, and if the lash does drift you're not tearing stuff up.  With a LLSR you also sometimes have to actually preload the valves slightly when cold which isn't good for the seats.

A LLSR is not as new of an idea as Cammotion wants you to think.  Really what it is is a hydraulic lobe profile with a solid roller lifter on it.  They do have some merit, and they've definitely developed new lobes specifically for LLSR apps, but people were doing this way back in the 60's.  Comp has some lobes like that too...our 415 hydraulic cam drag motor has these "hybrid" lobes from Comp and they run awesome, but for a ground up solid roller design they can optimize a bit more.

[shainiac]

That thing is going to sound wild!

[MPbdy]

The cylinder headssssss...done by BES.  BES does a lot of class engines and heads up stuff.  I got the chance to buy these pretty much at dealer cost when a customer backed out...I was quite happy.

BES and CID also partnered to make the most seriously badass cylinder heads in the world for LS engines.  Check this page out to see what level they're working on.

https://cidheadscom.myshopify.com/pages/be-ls-cylinder-heads

I'll just...give you guys a few moments





Neat to see they unshroud around the exhaust valve which is the only real weakness of the LS7 head.  The chamber hasn't been opened any more, but from a first look they need larger than a factory gasket, and should be biased away from the exhaust valve.

[MPbdy]

To go with the heads, I have brand new Del West titanium intake valves, and Ferrea solid stainless exhaust valves.  I also sprung for the Isky bushed solid lifters.  The bushings replace needle bearings in the wheel axle which have a habit of failing and destroying entire engines.  The redzone lifters are designed for endurance race applications like 24 hour races.





How about a titanium 2.200" valve that is lighter than a 1.61" stainless valve?  They are deceptively light to pick up and handle.





For the rocker arms I went with T&D steel rockers that are made for the stock eliminator class of NHRA racing.  The LS7 COPO motors retain the cast in pedestal mounts.  They're a very nice piece.  The next step from here is having the heads machined down to accept a true shaft rocker, but that'd be another $2500-3000 at this point...I'll try the pedestal mount rockers first.

[MPbdy]

So after mocking up the short block, the cam degreed in perfectly and the piston was about .008" out of the hole which is very near where I wanted it for optimal quench.  I will need to order a gasket for it anyway due to the larger bore, so once I get all the pistons in for the last time I'll be able to know the final thickness.






After all those steps I could finally get to the magic question of how much PTV do I have after grinding a huge ass cam and buying shelf pistons with small valve pockets...




And I got stuck and ran out of time.

The rockers don't clear the heads.  Not a huge deal, but need to go in and pocket them a little with a grinder for more clearance.

[MPbdy]

That thing is going to sound wild!

I can't wait for the sound!  Especially if I get it up to ~13.5:1 it is going to be gnarly.

[shainiac]

Do you plan on running pump E85? What kind of power should that head/cam combo be good for?

[MPbdy]

Do you plan on running pump E85? What kind of power should that head/cam combo be good for?

Yeah pump e85 and also 91 octane + boostane. I’ll do flex fuel with the Holley.

I think a realistic number is going to be 760 flywheel horsepower. I’ll run it on the engine dyno when it’s done.

[babillaracing]

very nice set up sir

[MPbdy]

Thanks everyone I've been really excited about this it just takes me about 5 times longer to do things.  It is fun to finally have progress to share and not just a pile of parts.

[Cobranut]

Thanks everyone I've been really excited about this it just takes me about 5 times longer to do things.  It is fun to finally have progress to share and not just a pile of parts.

Only 5x?  Boy, do I know that feeling. LOL

Nice looking project though.  I'd love to build one like that for my FD.    But $$$$$ 

[Exidous]

I'm working on a not insane version of your setup. Sleeved TSP gen 4 block. Full LS7 rotating assembly. Still working out the heads. I have a set of fresh LS7s but they've been cnc'd to 312cc on the intake. Far too big for me but the price was just too good to pass up.

Looking forward to more updates!