Lance,

Do you see any signs of detonation?

Pappy

A lot on #4, the one that cracked and burned and just a couple small pits on #1. Tops of all the rest of the pistons look great, including #8 with broken ring land.

Same situation with mine. Just upgraded the weak parts. Rods, crank. One thing we did was replace all 8 sleeves (Brodix aluminum block). We needed to replace 4. Then we would have needed to bore them .030" over, to match the other 4. Or, replace all 8, and now have a standard bore block, which will allow for some freedom in the future.

Only money... :G-Dub:

Might want to investigate the source of the detonation - usually an octane, timing, or AFR problem. Cast pistons tend to give up early (broken ring lands or cracks at the wrist pin), but even good forged pistons don't like detonation. Were you running an AFR gage or monitoring EGTs? With a nominal compression ratio, octane should not have been a problem, barring excessive timing advance. Sounds like there might have been something in the tune at some point that was causing problems - just my opinion.

Pappy

I was not data logging at the time, but I have plenty of WOT logs showing the tune performing as desired.

I'm still leaning more toward something happening in that cylinder that raised compression or lowered octane enough to cause the melting of the edge of the piston. There were several mechanical failures there and all of the rest of the cylinders were fine.

We may have been close to the edge and a minor variance put it over, not discounting that...but if it truly was only tune related, it would have shown more damage across the board and most likely would have happened earlier.

It had been pushing antifreeze out recovery tank for two events prior, indicating the start of the real problem. The burnt piston is more of a result of that problem than the tune.

But yes, I probably will back it back away from the edge next go ahead.

Too bad you had to tear it apart again Lance, but addressing the possible shortcomings will continue to make your engine more bulletproof. I enjoy following your journey because except for a minor setback such as this your car is a contender amongst much higher dollar builds out there. Keep it up and let us all learn and enjoy with you as you go.

Just throwing this out there, what were the ring gaps set to?

That is on my list of things to check.

This may be the answer you are looking for. A long rev limiter hit is tough on your bottom end, especially with cast pistons. When I had my ZL-1 built, my engine builder preferred I raise the rev limiter vs. bounce it off repeatedly.

OMG Todd, I had forgotten all about that incident.

You very well may be onto something there.

It appears it got wicked lean too.

Yes it did, but keep in mind that the zoom in on the chart represents just a little over 1 second. That said, it was still a brutal hit on the internals for sure.

And me... :D Can't believe I forgot about that until you brought it up.

That is what I was concerned about. Lean leads to detonation which is very hard on cast pistons. Melted pistons, cracked wrist pin bosses, and broken ring lands are common indicators.

Pappy

Edit: Lance, is your ECU's rev limiter ignition or fuel based? If it is fuel based (cuts the fuel), some builders recommend adding an MSD spark rev limiter set just below the ECU limit to avoid a lean condition when the engine is on the limiter.

Pappy, the ECU is set to pull spark at 6200 and when it hits 6400 it pulls spark and fuel.

That should be about perfect.

Pappy

It has now been 48 days since I hurt the engine in Barney taking it off the road.

I typically try to not take it off the road for longer than 3 weeks at any one time. Careful planning and working fast helps me get the car back on the road ready to enjoy quickly. The EFI swap took about 7 weeks which was longer than normal, but it was a HUGE job.

I have to say, it is really starting to bug me that I haven't even decided on a path to repair yet, much less actually started buying parts and getting things done. This will be the longest this car has been down since I first restored the underside of it back in 2008. I said there would be no hurry as race season was basically done for me anyway, then this whole Covid-19 deal happened...but I'm ready to get it moving forward soon I hope.

I've met a local machinist that is working on some pricing for me. Soon then after I'll be making some final decision on which path to take.

Meanwhile...I'll keep working on the Jeep.

Stay safe everyone...

Progress?

https://photos.smugmug.com/photos/i-...5xC9tX4-XL.jpg

Lance, that’s not an LS engine. You grabbed the wrong stuff! 😜

What?!?! :D

Big beautiful pistons that have been ordered...

https://www.jepistons.com/media/cust...170817-BAC.png

https://www.jepistons.com/media/cust...817-SID-01.png

https://www.jepistons.com/pistons-130974

With this ring set...

https://www.cnc-motorsports.com/je-p...08-4010-5.html

Which will be hung on these rods...

https://www.cnc-motorsports.com/medi.../scathbeam.jpg

Scat H-beam connecting rods are the strongest Scat connecting rods available by Scat. These Scat H-beam connecting rods are perfect for supercharged and nitrous applications. These rods incorporate a special doweled cap for specific cap-to-rod alignment and are profiled with extra clearance for stroker applications. Forged 4340 material with ARP 7/16 8740 rod bolts make them very strong and affordable. H Beam rods with ARP 8740 Bolts are rated to 750 horsepower on small blocks and 850 on big blocks.

https://www.cnc-motorsports.com/scat...ting-rods.html

The new rod length and comp height on the new pistons will put the top of the piston at the same height as the OE pistons. The OE piston had a 18 cc dish and the new piston has a 14 cc dish so that along with maybe a touch of decking and cleanup on the heads might make for just a bump in compression ratio but not a big deal. Bottom end should be safe to 7,000 RPM, it'll be interesting to see how high the top end can go now.

The rods and rings are on their way to me already, the pistons have to be special cut because of a bore size change, JE said 3-4 weeks, CNC said 5 weeks... We'll see. Block is disassembled ready to clean. Builder won't start machine work on block until pistons are in hand to be sure it gets cut perfectly. He can get started freshening the heads up though.

Glad to have this decision making part out of the way, now just have to find the money to pay for it all and wait in parts jail for a bit.

So I finally uploaded all of the pics I pulled down from photobucket a couple of years ago...and ran across some doozies.

Here she was in all her glory not long after I bought it...

https://photos.smugmug.com/1985-Mont.../L/Pose2-L.jpg

I had cleaned up and restored the bottom side before this picture was taken but hadn't touched much else.

305 vs 383

https://photos.smugmug.com/1985-Mont...L/OldNew-L.jpg

Newly tinted windows

https://photos.smugmug.com/1985-Mont...8160369-XL.jpg

GTO seat install

https://photos.smugmug.com/1985-Mont...6060920-XL.jpg

New Billet Wheels

https://photos.smugmug.com/1985-Mont...6060905-XL.jpg

Then I discovered racing...

These was taken at my very first test N tune...

https://photos.smugmug.com/1985-Mont...6180448-XL.jpg

https://photos.smugmug.com/1985-Mont...6180439-XL.jpg

It was all downhill after that... :D Thanks everyone for going along on this crazy ride with me.

New pistons have been cut and are on the way to me. Stay tuned...

I'm glad you got rid of the 4x4 look, Lance. It's a great looking car.

Lance,

Did the GTO seats require a lot of work to fit? Can you share some info. on how you fit them in? Seat tracks etc.

Thanks

Seats look very nice by the way!

Yes, they took some very custom brackets to make them fit. Its a tight squeeze for sure. Main obstacle is the crossmember on the floor on the passenger side, you have to raise the rear mounts up pretty high to get the seat tracks over the crossmember.

I'll look for the pictures of the brackets and post them up. As far as I know, I was the first to do this swap bit several others followed after and we all loved them. Search on montecarloss.com board and you'll see them.

Here are some pics of the brackets we made to adapt the GTO seats in.

Passenger seat

https://photos.smugmug.com/1985-Mont...ssseat3-XL.jpg

https://photos.smugmug.com/1985-Mont...ssseat2-XL.jpg

https://photos.smugmug.com/1985-Mont...ssseat1-XL.jpg

The driver's seat didn't have to be raised as much as you can see here.

https://photos.smugmug.com/1985-Mont...rsseat3-XL.jpg

https://photos.smugmug.com/1985-Mont...rsseat2-XL.jpg

Full power function was kept, here is the driver seat all the way back.

https://photos.smugmug.com/1985-Mont...alled04-XL.jpg

And all the way forward

https://photos.smugmug.com/1985-Mont...alled03-XL.jpg

They just touched the arm rest on the door panel and the center console and folded forward just like the stock seats for rear seat access. And the stock seatbelts worked great with them. I LOVED them...way better than the OEM seats. They just wouldn't work with the harnesses I wanted to run so they went to a new home.

Well done!

Thank you Lance for posting the seat info.

Got a big brown truck delivery at 930 pm last night


https://photos.smugmug.com/photos/i-...DvHLwLc-X2.jpg

https://photos.smugmug.com/photos/i-...BXfhXzj-X2.jpg

Parts are at the builders, work starts this week prepping everything.

....

Must have been tough to get to sleep after that delivery.

One of the things about my EFI install that bugged me was this.




Because I used an internally regulated fuel module, I ran just one fuel line up to the engine and dead headed the other end of the fuel rail.

Here you see the -6 feed line attached to the rear port on the fuel rail with a plug in the front port.

https://photos.smugmug.com/1985-Mont..._160715-XL.jpg

Apparently it is common with a dead headed system for the injector pulses to send vibrations back through the fuel line. This is what is causing my floor to vibrate. Here is how the fuel line is attached to the floor under the passenger foot well.

https://photos.smugmug.com/Other/i-K...L/61965-XL.jpg

https://photos.smugmug.com/Other/i-4...L/61966-XL.jpg

What is strange is if one or the other clamps is removed, the floor doesn't vibrate.

I heard of fuel dampers possibly working to quiet this down so after a little investigation, I picked this up.

https://photos.smugmug.com/1985-Mont..._112210-XL.jpg

http://www.radiumauto.com/Fuel-Pulse...Kits-P751.aspx

This also gave me a place to put my new Holley Fuel pressure sensor. I then built a bracket to mount the damper and sensor to the firewall.

https://photos.smugmug.com/1985-Mont..._105221-XL.jpg

The 90 degree -6 Hose fitting on the existing fuel line attaches to the input side of the damper and I'll have to make a new fuel line to go from the output side to the fuel rail once the engine is back in place. The fuel pressure sensor will plug right into the circuit on the Holley harness and then I'll be able to verify and log fuel pressure with the ECU.

Hope to have a progress report on the engine itself soon.

Wild. I've never heard of the fuel line causing an issue like that.

That's because modern EFI engine have fuel dampers built into the fuel rails.

Andrew

So, think about this as well. Modern fuel rails are all sequential fire, so 8 smaller injectors firing one at a time. This setup has 4 larger injectors operating in batch fire...so all 4 hitting at once each cycle. Much larger hammer effect back on the fuel line.

We have progress to report...look what's back on the lift once again!!

https://photos.smugmug.com/1985-Mont..._203108-X2.jpg

The builder is very happy with how the crank turned out, says they did "exactly what he asked them to do". He said it spins over very easily with the mains torqued down.

Here are some pics of the short block assembled.

https://photos.smugmug.com/1985-Mont...L/62519-XL.jpg

https://photos.smugmug.com/1985-Mont...a4/O/62521.jpg

Some of the additional clearance work he did to clear the new rods.

https://photos.smugmug.com/1985-Mont..._091125-XL.jpg

https://photos.smugmug.com/1985-Mont..._091148-XL.jpg

He should have it wrapped up by the end of this week if no more hiccups.

Looks like I need to get busy prepping the hole it's going to go back in...

Very nice! Glad to see it's coming together for you, Lance.

Took care of some piddly things today in preparation to put the new bullet back in place. I moved the oil pressure sensor from the boss above the filter to this boss up by the distributor. This keeps it away from the headers better and will give a better representation of the oil pressure on the top side of the engine.

https://photos.smugmug.com/1985-Mont..._135153-XL.jpg

Also got the distributor back in place finally...leveling the engine out helped stand the oil pump drive straight up and centered which let the distributor fall right into place.

Since I moved the oil pressure sensor and added a fuel pressure sensor, I had to dig into the bundle of wires under the AC and on the firewall and since I was there anyway, I cleaned them up a bit. The fuel pressure sensor lead to the ECU was tucked up under there last summer since it wasn't being used


https://photos.smugmug.com/1985-Mont...622_104701.jpg

May not look like much but it's MUCH neater than before.

https://photos.smugmug.com/1985-Mont...622_143825.jpg

https://photos.smugmug.com/1985-Mont...622_143841.jpg

Cleaned up the alternator plug as well.

https://photos.smugmug.com/1985-Mont...622_144240.jpg

I then used a tap to clean all the bolt holes in the heads and block and put the engine mounts on. This gets me pretty close to ready to put it in the car. Might get around to that tomorrow, we'll see how it goes.

Clean engine compartment.

15 minutes from this...

https://photos.smugmug.com/1985-Mont..._093124-XL.jpg

To this...

https://photos.smugmug.com/1985-Mont..._101744-XL.jpg

And that included taking the hood off and putting it back on and lining it up.

I might have just a bit too much practice at this...