AlkyIROC

Went out for some track time tonight during the street legal night. Traction wasn't great. On the first pass, I lost traction before the 330' mark, tried to get back into it then just coasted across the finish line with a 11.873 @ 78.55 mph.

Went up for a second pass. By then the deck truck had already carried back 2 other cars. I spun a little off the line with only a 1.411 60' time. I stayed in it and managed to keep it powered after I shifted. Just as I crossed the finish line, something popped and the engine had a clatter. I killed the engine, moved to the side of the lane and coasted all the way down to the end of the track.

The oil containment pan had some oil in it but I couldn't see where it was coming from. Pulling the dipstick, I could see it was bent so I knew there was some sort of bottom end damage. Deck truck picked me up and a bunch of guys helped push the car into the trailer. When I got home, I cranked the engine over and there were no noises but it was hard to start. Once started, there was a noticeable vibration and some slight noise but I was still able to drive into the garage running on 7 cylinders.

I saw a trail of oil coming out on the drivers side. Once in the garage, I was able to get a better look under the engine and could see a hole in the oil pan right about at #7 cylinder. Looks like it threw a rod. Since there was no indications of anything wrong before it happened, best guess is it snapped the rod bolts. I won't know the extend of the damage until the engine gets stripped down. This isn't the first rod thrown in this engine but I haven't blown an engine since 2006. The block already has 2 sleeves in it.

I crossed the finish line with only a 9.415 but a record setting 150.45 mph so the engine was making a lot of power for that MPH. I took the car across the scales before heading to the track and the race weight is 3020 pounds. 1785 on the front and 1235 on the rear. With that MPH, the engine was making 802 HP uncorrected and 904 HP corrected for altitude. The DA was just under 5000' on that run.

mw66nova

iTrader: (13)

so what's the plan now?

AlkyIROC

Depends on the damage. Rebuild but not sure if going to an overbore to make a 555 or 565 is worth it yet. I'll probably need to get at least one new con rod. I can almost expect a bent valve and possibly crank damage. Might need another sleeve. Tear it down, get replacement parts. Get it all balanced and machined again and put it back together. Hopefully I'll be back on the track before the end of the season.

The 8740 rod bolts will have to go and be upgraded to L19 rod bots.

I really wanted to race in next weeks Father's day race. It's an Iron man race.

mw66nova

iTrader: (13)

with all the trouble you have with that bbc...i'm thinking a turbo 5.3...it'll be just as fast

greezemonkey

iTrader: (14)

awh man..sorry to hear that. your season just started out too. Those 8740 are rated for 800 hp. I always have used the 2000`s, I`m skeptical of the l19`s because of the care needed around them, but they are or were the top bolt, guess arp has something later and greater now. What rods were you running in that and how many passes on them? Hope all is okay with the block/crank

AlkyIROC

Eagle H-beam rods. Looking back through my logs, the rods have 166 passes on them.

Hmmm. Just looked through the ARP catalog about the L19 bolts. Must be kept well oiled and not exposed to moisture. Even with the vacuum pump on the engine, there will always be some moisture in the crankcase. It's not like my engine is used in a boat. Maybe the 2000's would be a better upgrade.

There are a few better bolts than L19's now. Crower and Carrillo makes some H-11 tool steel bolts but I think they're only designed for their rods.

I think the 800 HP rating is a little high for 8740 rod bolts even though I may have pushed it to that. The rating can also be as low as 700 hp. The L19 rod bolts are rated at 1500 HP. From what I can find, the 2000's are rated around 900 HP but may be higher.

greezemonkey

iTrader: (14)

Wow I have twice that on my eagles rods...6.385 with arp 2000`s and Ive regularly put 11-1200 hp to them, lucky I guess. You know that makes me think, I`m building that 548 right now and I bought the Callies I beam rods and they are rated to 1400 hp and they have the arp 2000 bolt. With the alcohol motor moisture is always present is it not?

AlkyIROC

I don't know how much better an H-beam rod is over an I-beam. At least when an H-beam rod gets damaged, it easily breaks in 2 preventing more serious damage. An I-beam rod will bend a lot more before it breaks and could end up taking out the block. I've pulled bent I-beam rods out of diesels that have hydraulic locked.

Damage pics!

The oil containment pan did it's job but the sides beside the sump should be taller. This pan has 3" sides and the minimum requirement is 2" sides.



Holes on both sides of the oil pan and right at a couple of mounting bolts. The one bolt on the drivers side broke when it was hit and I had to fight to get the one on the passenger side off.





Parts found inside the pan. I suppose a deep sump pan is good for something. It held the parts and still had a few quarts of oil in it.



Just as I suspected. It looks like I broke the rod bolts



Crank damage and looking at the #8 rod. The picture makes it look worse than it is. The #7 piston is about half way up the cylinder. I won't know if there's any head damage until I get the head off. Probably won't do that until I get the engine pulled.



Looking up into #7 cylinder doesn't look that bad. 2 rods, maybe a new crankshaft if it can't be repaired or fails a magnaflux, balancing, bearings and gaskets. Head and valvetrain damage is unknown right now. As long as the piston didn't smack the heads or valves, it probably survived since it's up in the cylinder. Best guess is I may get it back together by mid July but that's being optimistic.

DIGGLER

iTrader: (1)

these rod bolts are listed as being good up to a certain hp.... but the real important things on rod bolts are rod/piston weight, stroke, and rpm. if you have a very heavy piston and rod, along with a big stroke turning some rpm, there is going to be alot of stress on the bolts.
sorry to see the carnage, but it looks like a fairly easy fix as long as it didnt cause any other problems than what you have pictured. crank looks fixable for sure.

Shagwell

Ouch!!!

Glad you had the containment pan, and glad it did it's job. - I've done those donuts before and they're not fun, to put it mildly.

AlkyIROC

The engine is still in the car but I got all the exhaust off, the intake and the one head. Both valves in that cylinder are bent and the piston is scrap. The exhaust valve took most of the abuse. The cylinder doesn't look too bad but a couple of nicks down near the bottom may take more than a hone to clean up.

I've been doing some research and I think I'm going to just go right to a 0.100" overbore and make a 565. The heads, cam and intake can easily support the displacement.

This may now take longer than I thought to get back together. An optimistic mid July may turn into mid August. The longest wait will be for special order parts. It always sucks because all the special order stuff needs to come across the border, takes forever and costs a lot more just to get it across the border. NAFTA does not help the small consumers trying to save a buck.

On the upside, a crank and rods with the ARP2000 rod bolts are in town and in stock. The L19 rod bolts are special order.

Orr89RocZ

iTrader: (20)

man sorry to hear about the damage but its been a good run with no issues since 06? thats not too shabby.

ARP 2000 bolts should do ok, definately better than 8740's. I'd try those and see what happens. I think its mainly piston/rod weight and rpm rather than HP that stresses rod bolts, like said above a few posts up.

AlkyIROC

One other thing I discovered last night, not all wrist pins are the same. The wrist pins that came with my JE pistons are fine for average HP race engines but they are only .150" wall thickness. For the HP level I'm at, I could use some wrist pins that are at least .170" wall thickness or even go to a tool steel wrist pin. To help reduce the weight of the thicker wall wrist pins, they're also available with a tapered wall.

It's something else I need to check when ordering new parts.

When I got the engine balanced, the weights were not that bad. The target bob weight for the crank was 2300 grams and mine was 2330.

Shagwell

Wrist pins are a grossly over-looked component, yet are also a huge key in reliability. - Wrist pin failures are likely one of biggest causes of failure in race motors, yet in most cases people will assume the rod or piston was to blame.

We run tapered tool steel in the nitrous stuff, straight heavy wall tool steel in the blown stuff.

AlkyIROC

I've been sitting on my butt most of the week but at least most of the engine is stripped down enough to know what parts are required and it's still in the car. I've done a bunch of number crunching all week on what to do for a rebuild. The cheapest route would be to just repair the damage and make it a 540 again but at this point, it's just as easy to go bigger.

New crank and rods will be purchased just to be on the safe side. Old parts can always be sold off as there's nothing really wrong with them. The simplest way to go bigger is to buy 0.100" overbore pistons, keep the same stroke and make a 565. I can go to a 4-3/8" stroke instead of 4-1/4" for the same price and with a 0.100" overbore, make a 582. The 582 rods are longer than the 540/565 rods. The rod, piston, wrist pin weight for the 582 is less than what the parts I need for the 565. The JE pistons I picked out come with 0.150" wall 51S wrist pins. I decided to upgrade with 0.180" wall 52S wrist pins instead. The weight saving by using a tapered pin isn't enough to justify the extra cost and even the straight pins with these pistons will be lighter than the 540's.

All the parts I wanted are special order which was no big surprise. Expected arrival time is about 2 weeks. Then add at least 2 weeks for machine shop work. More time for assembly and installation. There's no reason I can't get the engine back together and get back on the track before the end of August to at least finish off the race season before the track closes for good next year.

Punching in numbers into Dyno2003, the HP level stays the same from the 540 to the 582 because the software bases the output on the flow number of the heads. The 540's numbers never matched what I was getting on the dragstrip and I've never put it on a dyno. The software does show that the peak numbers will occur at a lower rpm so instead of shifting at 7500, I'll only need to shift at around 7000 with the bigger engine. Torque will be higher with the longer stroke. Dyno 2003 predicts just under 900 pounds of torque from 5000 to 5500 rpm and even at 7000 rpm, it should be making 800 pounds of torque. The HP curve is flat at 1050 from 6500 to 7500 but these are all just simulation numbers. Real world numbers are what matter the most.

When it's done, it should be a real fun ride and there's no reason it shouldn't now give me that 8 second timeslip.

I'm surprised there wasn't more damage. Both valves are bent but there's no damage to the head other than the valve seats need to be touched up and the spark plug threads need to be cleaned up after removing the damaged plug. No damaged rockers, no bent pushrods, no broken springs however the exhaust valve keepers almost failed because the exhaust valve took most of the abuse.

More pictures of sacrifices to the god of speed and acceleration.

Orr89RocZ

iTrader: (20)

ouch thats nasty

Shagwell

Was that spiro-lock knocked loose or were you starting to pull it?


- I have a 4.375x4.600 combo sitting on the stand right now as the new nitrous motor. I went with a 6.700 GRP pro-mod rod, but as an NA bracket motor it's more logical for you to stick with steel rods.

AlkyIROC

The spiro-lock was knocked loose. That's exactly the way I pulled it from the cylinder. A 6.700" rod won't fit in a short deck block.

Shagwell

Forgot you have a low-deck. I'm not a fan of the 4.375 crank in a low deck block, too much rod-to-piston angle and/or too little compression height on the pistons. - It's probably ok for an NA motor, but a ticking bomb with any power adder.

AlkyIROC

That's why the rod length is also increased. With the 540 and 4.250" stroke, I was already using 6.385" rods which are .250" longer than normal BBC rods. Increasing the stroke to 4.375" means increasing the rod length to 6.535.

The local supplier carries Probe and JE pistons. Probe doesn't make a piston for this application but JE does. I also chose a piston with the largest dome possible. Estimated compression ratio will be 14.7:1. Since I've never cc'd the heads, I don't have exact numbers.

Shagwell

The longer the rod, the shorter the compression height will be of the piston. Increased stroke further compounds that. With the 4.375 and 6.535 rod in a low deck the wrist pin will actually be into the 2nd compression ring land. - Makes for a lighweight piston, but any power adder would knock the top off of it(though, obviously not neccessarily a concern for you)

No reason not to get all the compression you can with alky. We've run 16:1 before NA on alky.

AlkyIROC

The pistons are not the nitrous series versions as I have no intention of using NOS or any other power adder. Just open chamber dome design for conventional heads but the pistons are also gas ported with low tension oil rings.

Compression height is 1.060" and the pistons are very light at 558g.