The All About My 1980 Pontiac LeMans Station Wagon Thread...

[motorhead]

Well I just ordered a shit tonne of parts for this thing from Car Shop Inc (motor mount plates, tools), Speedway Motors (fuel system), Summit (fuel system, prop valve, tools), UMI Performance (roto-joint rear UCAs, LCA relocation brackets, tie rod adjusters), Speedhut (Revolution series gauges 4" tach and speedo; and 2-1/16" voltmeter, oil press, water temp and fuel gauges), Eastwood (paints and seam sealer), Amazon (car audio and fuel tank sending unit from an Astro van), and SDPC (CNC LS2 heads, gaskets and LS7 roller lifters) etc.

[SuperSix]

That's a couple hundred pounds, tops. You aren't even close to a "shit-tonne".

Step up your game, son.

[motorhead]

That's a couple hundred pounds, tops. You aren't even close to a "shit-tonne".

Step up your game, son.



 

Working on ordering a built trans/converter for the TBSS, a custom cam (and supporting mods (ie. springs, pushrods, oil pump, etc) for the wagon, and a fuel pump.  Getting closer to that tonne.

[motorhead]

Ordered the cam this morning from Speed Inc and it looks like this:

226/230 .605"/.609" 113+3

Should work very well from off idle (ish) to 6500rpm. I will likely have to run a 3000 converter with it to offset the cam and the 3.08 gears. The LXL lobes I chose from Comp are softer lobes designed for LS7 applications with a 1.8 rocker, using the LS1 1.7s softens them up even more. This made the most sense since the LS7 cam is a good swap into any LS motor, and the added advantage is the powerband is moved lower to be more usuable by advancing it 3 degrees.

"The LXL series is based off the Comp Cams LSL profiles but are optimized with lower acceleration rates and softer closing ramps for less valve train noise and better stability with the high ratio LS rocker arms. Great choice for street/strip applications and engines that see a lot of highway driving with the occasional weekend at the autocross or drag strip. For cathedral style LS heads, Comp recommends using this lobe on the exhaust and an LSL lobe on the intake when using the stock 1.7 rocker ratio. For applications using 1.8 or higher ratios or LS7 style heads, Comp recommends using this series on both the intake and exhaust lobes for applications that demand a quiet valvetrain and proven power increases. These lobe designs provide excellent torque and valvetrain durability for road race, street/strip, and endurance applications. Please consult with the SDPC Professionals to make certain you have the correct valve spring and valvetrain components to match your custom cam selection."

I chose to do the LXL/LXL vs the LSL/LXL combo to save some wear on the springs as the LSL lobes would have been a touch taller at .612" or .614"; the springs chosen are good for .625" lift.

These are the comments from a noted cam spec guru (regarding the LSA supercharged engines): "LXL is a bit slower then LSL and has softer ramp. If using Comp I like the LSL/LXL or LXL/LXL combos on these cars depending on rocker ratio and how the heads flow. Both of those lobes are easier on the valve train then some of the other designs popular in the LSx world (XER, LSK etc..) even though they have a pretty good amount of lift even with a stock rocker. The LXL lobes offer a relatively quiet valve train with proper setup (compared to many other LS lobe designs)."

Hopefully this will get us in the 8lbs/hp range once the car is all said and done.

Fun times.

[nocooler]

Speed Inc ftw 

I've got their SI5 in my bird. For an old grind with old lobes it does pretty well

I'd run no less than 3600 stall behind a stock LS1 - let alone a cammed one 

[motorhead]

Speed Inc ftw 

I've got their SI5 in my bird. For an old grind with old lobes it does pretty well

I'd run no less than 3600 stall behind a stock LS1 - let alone a cammed one 

They did try to sell me a shelf grind and I had to fight to get what I wanted.  But, otherwise it was an okay transaction.

I managed to get my credit card frozen today between them and the Level 5 trans we ordered from RPM for the TBSS

[nocooler]

Their shelf grinds have proven themselves. The thing about LS's it you really can't cam them wrong. They make good power regardless.

You'll be happy with RPM's trans - they are good dudes.

[motorhead]

Yeah the LS family of engines are cam whores.  But, that is because they are all undercammed to begin with.  My biggest concerns were where and how this motor would make power; and not just produce a cool guy dyno number.  Area under the curve and driveability were key.

[motorhead]

Spent some time running some quick simulations on the motor and potential combinations of parts.  Each of these is running stock exhaust manifolds and mufflers... but, it gives an idea of where and how it should make power.  Headers look like they will really wake this thing up (not shown).

[motorhead]

So while I was running simulations on the probable engine combos I could go with, it kept nagging at me as to how much potential was left on the table with the addition of headers to the mix.  The problem was that if I go with headers I would lose the ability to run cats, as I was planning on running stock F-body manifolds and cat-deletes (with the stock cats waiting on the shelf for emissions "issues"). The other issue was noise as I would see a serious increase in cabin noise (NHV) with headers.  Also, because there isn't a good stainless G-body swap header on the market, I wasn't inclined to buy a mild steel header (coated or otherwise) regardless of price, or do the same with a small tube eBay F-body header or Pacesetter. Then I saw that Speed Engineering released a set of 1-3/4" primary headers (and look like a knock-off of the Pacesetters) for cheap and got to thinking... 

After a lot of research I came to the conclusion that these headers (which I can afford to chop up to suit my application) and some 3" cats should flow/sound similarly to my previous plan of manifolds and delete pipes (not overly loud through a muffler).  However, because the kid in me hasn't left the building yet, I figured I should continue with my plan to run electric cutouts so I ordered some stainless ones off eBay.

Catco 6907 flow numbers (365cfm @ 28" H2O): http://forums.corvetteforum.com/1550686662-post3.html

Straight pipe flow numbers (doesn't list test pressure): http://www.exhaustvideos.com/faq/how-to-calculate-muffler-size-pipe-diameter/#easy

And a really long paper I read on the way a close-coupled catalytic (ie. a cat mounted on a manifold or header collector) works (hint: having a good cold side (post-cat) is mandatory to reduce any restrictions on flow):  http://www.mech.kuleuven.be/en/doctorates/persoons.pdf

***Bonus reading: http://www.mie.uth.gr/labs/ltte/grk/pubs/exhsysht.pdf

I already have some long standing experience running a headered/3" catted car and have done as much as 116mph through generic ceramic core catalysts like the Catcos using a small-shot nitrous Chevy small block.  So I know that power can be made with them in place, granted that was a full free-flowing 3" dual exhaust system and not the dual 2.25" crush-bent Flowmaster equipped system I will be attaching this to in the wagon; but, that is what the cut-outs are going to compensate for.

There is a general rule of thumb that 18" header extensions are best for most applications when using open exhaust, so these may have to be integrated into the cut-outs; as well they help prevent having the 02s wash out when the cut-outs are open (very bad for closed loop functionality). An example of the theory: http://www.headersbyed.com/hc_cheapperfgains.htm

Using a "small tube header, open exhaust" the power increase is quite notable over previous iterations (see attached); but, in no way do I expect to see 500hp at the crank - this is just a behavioural indicator.  A small single plane intake does some wonderful things too.

[nocooler]

Cats are only going to kill a few ponies Mike.

When it comes to fbody's the biggest issue is the y-pipe.

I've ran over 130mph in the 1/4 with cheap ebay longtubes (which are comparable to the speed engineering pieces) going through a non smooth 3" to 3" y-pipe - it's closer to a T that an Y.

There is a pile of hp in the y-pipe I just haven't been able to weld much the last couple years.

If you want to take the next step - vband the cats so you can swap them out for test pipes

[motorhead]

Cats are only going to kill a few ponies Mike.

When it comes to fbody's the biggest issue is the y-pipe.

I've ran over 130mph in the 1/4 with cheap ebay longtubes (which are comparable to the speed engineering pieces) going through a non smooth 3" to 3" y-pipe - it's closer to a T that an Y.

There is a pile of hp in the y-pipe I just haven't been able to weld much the last couple years.

If you want to take the next step - vband the cats so you can swap them out for test pipes

Oh I know, but I really like an un-muffled exhaust.  It was Natasha that insisted that I put cats on the car; so I had to start shopping for a means to keep the power up. To this point I can't "remove" the cats; and I've been told to find a way to put them back on the TBSS. LOL!

I've been out in the garage today working on the wagon for the first time in months when I realized that I'd overlooked that early G-bodies have that odd-ball transmission cross member and lack the frame extension for the later piece.   The reason this is important is because of where the cats will ultimately be placed, and the existing cross member: Sits. Right. There. FML... more fabrication.

[motorhead]

Updates!

Finally got the rear wheel wells finished off - shown in etching primer (seam sealer and top coat is done (no pics), waiting on undercoating).  We also got some (actually a lot) parts in the mail and waiting for more to arrive (soon?).

[motorhead]

Moar pics!

[motorhead]

And now some "cool guy" parts... including a lil' donkey dick camshaft.