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To all that know the saga that is blowing up the BSP car, i took some pictures of the carnage.  I managed to spin 6 of the 8 rod bearings and 1 main bearing.  Somewhere along the line I also cracked the crank.  The engine is currently at the machine shop getting a guestimation of the total damage.  I didn't think the pistons or cylinders were marred up at all, so they should still be fine.  The machine shop (Borchardt's Speed) will let us know what the real damage is.

 This is the worst of the rod bearings.  It and it's other half eventually got dis-formed enough that they kind of meshed together and formed a 1 piece rod bearing.

 

The section on the crank these bearings came from:

Some other bearings:

 

So, does anyone have a spare LT4 laying around? 

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It's going to an interesting season...

Hope a baffle oil pan!!!!!!!!

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MIKE MACHI
CREW CHIEF
USGUYS RACING
IM IN SHAPE! ROUND IS A SHAPE

Nice work.  I have not heard many, if any good things that I can recall about Bochardts...might want to shop around.  Get some more opinions...

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Erik B.
Wisconsin Autocrossers, Inc
www.waiautox.org ___/\___/\___/\___/\___/\___
2007 Mazda6
2000 "Fozda" ZX2 S/R--ST unCivic

I cant wait to see the shiny new oil pressure warning light that your going to have on the dash!  Pops is probably going want something in the 6" 200 Watt range before you get to drive it again.  :)

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Chris Shay, 2004 Z06

Ditto Erik's thoughts on Borchardt's.  They're probably cheap, but file that under you get what you pay for.  I asked the boss about Milwaukee area shops, and his recommendations, in order are: C&S Performance and AMS.

Have you looked into getting a short block from GM?  With a spun main you're going to need to have the block line bored to true it back up, plus I can't believe you didn't score up the cylinders with as much debris (formerly rod bearings) as the crank pins must have been throwing off.  Plus, from the strict perspective, you're going to need to see how much material you can remove per the shop manual for SP legality.  From the practical perspective, you really aren't adding performance, so the vast majority won't care.

Have fun!

-Steve

Also, remember to be VERY SPECIFIC with the shop about what is allowed by our rules for the engine prep.  Basic things that shops do, like bead blasting the ports, are not allowed in street prepared.  Familiarize yourself with section 15 (street prepared) and 13 (stock, which SP inherits) before the builder starts making chips.

-Steve

Thanks steve, I appreciate the input.  We sent our 66 to Borchardts, but they're being a little lazy with the 96 right now.  I'll give the other machine shops a call.  I've gone through the new rule book about rebuilds, we can go 30 over on the block, and the crank and rods need to be stock or no lighter than stock.  There are a few other small things, but that's the gist of it.  It's going to be an interesting few months, I'm hoping to get all of the machine work done by March 16th at the latest so I can re-assemble during my spring break.

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It's going to an interesting season...

Brad - not to add to your stress level, but from personal experience, many if not all performance / race shops, especially the good ones, are already under pressure with engine projects that people are expecting by the "beginning of the season".  Hopefully you'll be able to find a shop that is up to the task.  Possibly the global economic downturn will work to your advantage.  Your odds also improve by doing the assembly yourself.  My impression of the boys on South 27th Street is that they do good work on their own cars & most others get a back seat.  The "burning of the midnight oil" season will soon be upon us...

If you have some extra money to spend, rumor has it that advancing the stock cam helps the LT1 breath better up top.  I cant remember if the LT4 has the same cam.  Just a thought.  That would certainly require a retune.

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Chris Shay, 2004 Z06

The LT4 cam profile is a little different than the LT1, but not a whole lot.  I'm pretty sure advancing the cam is allowed in street prepared too... This could be a job for the computer dyno sim....

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It's going to an interesting season...

I have actually had very good luck with Weaver Auto Parts' machine shop here in Madison/Sauk City. Do a good job of building everything per my specs... built a few engines for customers that way too. They are also quick on turnaround time as well.  If you have the specs and don't need them to do too much of the digging in that department they do a really nice job for a good price.

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Steve Nackers
'98 BMW 318i

Well, Borchardt Speed finally finished checking the block (kind of) and Pops is going to pick up the pieces tomorrow morning.  Crank is cracked, cylinders need at least a hone.  When the hone is done, there will be about 3 to 4 thousands of clearance.  This will probably be ok for a street motor, but for a motor that's going to live racing, is this too much clearance between the cylinder walls and the pistons?  

 

Going to a full rebuild (40 thousands over is street prepared legal) will add somewhere in the neighborhood of $750 - $1000 to the build cost (block machining, new pistons, etc.).  The short blocks were discontinued by GM in 2000, I haven't been able to find any other short blocks elsewhere, the LT4's are more rare than usual.   Right now it's looking like a full rebuild is in the works.  It's going to be an expensive 5 HP.  

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It's going to an interesting season...

The clearance depends ENTIRELY upon the piston.  For some forged pistons that isn't even quite enough clearance, for some cast pistons it is too much and can lead to some problems with rings and result in scuffed skirts on the pistons themselves. So its rather relative/specific to the engine unfortunately.  I'm not a chevy motor guy at all, so can't answer much there. 

 As long as they are not sleeving each of the cylinders it only costs about 30 bucks per cylinder usually to have them bored out and honed.   You should always deck a block when you do work on it, and I usually did an align hone on the crank mains just to improve their alignment if it was needed and to set good bearing clearances. I'd also upgrade to a nice tri-metal performance bearing (clevite should make some for you) and none of that should be real expensive.  An align hone is about 250 ish. 

 I have multiple accounts, so I can easily get you pistons at my cost if you need them.  I have accounts with CP Pistons, Mahle, Oliver Rods, and a few others. I don't do much with the domestics, so I probably have more access than I realize and can get you a few brands that I might not realize are what you need. 

Bart might be good to talk to as Pegasus may have some options for you too... but he more likely than not would need to make a profit... I don't :)

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Steve Nackers
'98 BMW 318i

Let me guess....Mobil 1 oil?

 

Same thing happened to the Camaro I had. In Peru.....And that was when I drove the car to and from. Made it home though-and that's about it.

 The shop doing the work wanted to replace the rods with GM "Pink" rods......That's just one example of things they will do that aren't legal. Maybe not an advantage but not legal....You gotta be involved in the process.

The Canton road race pans are really nice. Add an extra 1qt capacity and have a built in windage tray, scraper, and baffles to keep the pickup submerged.

DO NOT let them talk you into a high VOLUME pump. This will only try to create the same problem you had. Standard volume pump, high pressure spring. Basic stuff for those guys. Also make sure the pump comes apart. Brand new oil pumps can be downright NASTY inside. You would be surprised. Blue print a stock replacement oil pump, clean it, install a high pressure spring, and then loctite the cover bolts down.

May as well get a bolt on pickup while your add it....good news is that it comes with the Canton pan.

 

In my mind the stock hyperutectic pistons are just fine. They are more thermally stable than forged, which means better ring seal. 

 

A S/P rebuild nets you an increase in displacement with an overbore, an increase in compression due to that overbore, and from the .010 milled heads, and from much better oil control. If the engine is to the letter of the rule there isn't much to be gained. (over a stout good condition stock engine)

 

Have you found any source of replacement LT4 shortblocks?

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DSP 325IS.

Nope, we've found a source of stock replacement GM rods (from an LT4), as well as pistons and the whole works.  It will be the exact same engine as when it blew up, only .030 overbore.  By the way, stock LT4 parts are next to freaking impossible to find.  Seriously.  

We're going with the canton pan, standard volume oil pump with the high pressure spring, accusump, etc.  It is being built exactly to the rule. 

It's going to be a very reliable engine when it's all said and done, I'd rather not have to do that again.

 

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It's going to an interesting season...