Rebuilding Dad's Panoz; LS1 swap

[NZGTRA17]

Originally Posted by Cobra4B

Haven't taken the pan off... got the engine/trans out and put it on a tire. First order of business is to get the chassis ready for the powdercoater which means test fitting the new engine/trans and doing any/all welding i.e. filling holes, relocating mounts/brackets, and welding in a proper harness bar.

~Brian

Coming along nicely Brian.

You know you have to put the stock 5.0 block Ford runners out of their collective misery at some stage though..........so they get to weep over those broken main webs that most likely caused the demise of the crank as well!!

Will post a photo of my new "bronze" calipers at some stage. They will get the same treatment this weekend as running an hour long race at another tight circuit.

Kel.

[Cobra4B]

Got the engine out of the crate and onto the stand. Need to do some basic prep for road course duty:
1. LS6 springs
2. LS2 timing chain
3. LS4 high volume oil pump
4. ATI balancer
5. Kevco baffled oil pan
etc. etc.

[Cobra4B]

Edelbrock valley cover (no knock sensors)


Old-style LS1 coolant pipe and Performer RPM manifold

[Blue Streak 21]

Brian;
Why did you pick the Performer RPM maniflod? Did you consider the Victor Jr?

[Cobra4B]

Originally Posted by Blue Streak 21

Brian;
Why did you pick the Performer RPM maniflod? Did you consider the Victor Jr?

Yep... but every single post I read on LS1tech and every single magazine comparison pushed me to the dual plane setup for this application. The performer RPM makes mower power/torque in the 4000-6000 rpm range. It's really only over 6000 rpms that the Victor Jr. takes over. This engine will be shifted at 6200 with a 6500 rpm rev limiter.

http://www.vetteweb.com/tech/vemp_0612_ls2_crate_motor/

http://www.carcraft.com/techarticles...e/viewall.html

[Cobra4B]

Snap goes the crankshaft. The mains are all intact, rods banged up but all intact as well.

[NZGTRA17]

Originally Posted by Cobra4B

Snap goes the crankshaft. The mains are all intact, rods banged up but all intact as well.

I guess what you will never know Brian (unless crank breaks are looked at under electron microscope......) is whether the crank went before No 2 main web or vice versa. There are quite a few 302/347 failure pics on the web that look very much the same as yours. Common factor is crank and web breakage and usually at no 2 main.

Nice looking rods. Way to good to put into a stock block!! Any idea what the crank was? What balance was the engine, 28oz or 50oz?

Kel.

[Cobra4B]

What causes the breakage? The engine was only making around 370 rwhp. Is that simply too much for the actual block to to point the main bearing web fractured? What would cause a crankshaft to just snap other than bad harmonics? This was only a 6000 rpm motor. I don't know what crank it was, but I know it was quality stuff. I think the engine was 28oz balance.

[PanozDuke]

Originally Posted by Cobra4B

What causes the breakage? The engine was only making around 370 rwhp. Is that simply too much for the actual block to to point the main bearing web fractured? What would cause a crankshaft to just snap other than bad harmonics? This was only a 6000 rpm motor. I don't know what crank it was, but I know it was quality stuff. I think the engine was 28oz balance.

What I have been told by an experienced 5.0 engine builder is that the production block, properly deburred and with the 50 oz imbalance is all done at about 400 hp. I believe that was flywheel hp. He was addressing motors used in drag racing where the shock loads are higher than road racing. An internally balanced crank with studs or 28.2 imbalance and stud girdle raise that to 450hp. I'd say your motor was within those limits. If the block had been previously tweaked or had an undetected flaw, that would better explain this failure. Even high dollar cranks can be defective. Cobrafang had a forged and carefully assembled 347 break the crank at the number 1 main at less than 4000 rpm. The block was intact. The crank was an Eagle and they replaced it free after examination. Stand up company. Those failures of quality parts are rare, but happen.

Mike

[NZGTRA17]

Originally Posted by Cobra4B

What causes the breakage? The engine was only making around 370 rwhp. Is that simply too much for the actual block to to point the main bearing web fractured? What would cause a crankshaft to just snap other than bad harmonics? This was only a 6000 rpm motor. I don't know what crank it was, but I know it was quality stuff. I think the engine was 28oz balance.

I think the first thing to bear in mind is the "only" 370 rwhp bit. These blocks are emmissions era parts that have been optimised at the factory to be cost effective to make (i.e. as little material as possible) and to withstand thier design loads. The factory hp rating for these engines would be lucky to be over 210 rwhp. So with a litte rounding we are at nearly double the factory output at 370 rwhp. I ran mine to 390 rwhp and did a 6 hour endurance race on it but pulled it after that as I expected it to chernobyl shortly thereafter.

The actual failure mode is debatable. I am sure that some are crank failures and others are web failures that cause the crank to fail. If you look at the common aftermarket band aids available (botton end and valley girdles) they target a common issue. Lack of torsional rigidity in the standard block. This is caused by the main webs having insufficient material to handle large torque loads.

If you compare the standard block to a Dart or World Products block it is night and day. The Dart block I am using has so much more material in the critical areas that it is easy to see why the standard block is a failure waiting to happen. At the end of the day there is prep that can be done to assist but the block will always be a weak link that can and is likely to lead to failure. There is loads and loads of speculative guff on the web about what the 5.0 block can and cant withstand. The best advice I saw written was why put H beam rods into a block that will fail before the benefits of the H beam rods are required.............(ditto for forged cranks as the block flex is likely to aid in breaking a forged crank).

Just one ex 5.0 stockblock runners views.........(and I never broke one)!!

Kel.

[Cobra4B]

Finally got the chassis completely stripped. Ready for a power-washing then going to do some welding and then off to the powdercoater.

[Cobra4B]

Chassis degreased and powerwashed. Doesn't look like much but getting all the adhesive residue from the old heat insulation on the tub was a chore. Time for welding. Going to weld up all the holes from the rivets that held on the old heat insulation panels, weld in a proper harness bar, and relocate the steering column a little etc.

[Cobra4B]

TKO 600 and QuickTime bellhousing from Liberty Gears showed up today

[NZGTRA17]

Originally Posted by Cobra4B

TKO 600 and QuickTime bellhousing from Liberty Gears showed up today

Nice. Did you get standard synchro TKO?

Make sure you clock up the trans mounting faces on the back of the bellhousing Brian. Flat on back face under .005" and concentricity of location hole. Cant speak for Quicktime products but many need eccentric dowel pins to get them within tolerace for racing. Otherwise you can have shifting and input bearing probs.

Kel.

[Cobra4B]

Originally Posted by NZGTRA17

Nice. Did you get standard synchro TKO?

Make sure you clock up the trans mounting faces on the back of the bellhousing Brian. Flat on back face under .005" and concentricity of location hole. Cant speak for Quicktime products but many need eccentric dowel pins to get them within tolerace for racing. Otherwise you can have shifting and input bearing probs.

Kel.

It has Liberty's synchro package and the optional .82 5th gear. QuickTime has a good reputation and for the price of that bellhousing I sure hope it's square and oriented correctly. Any tips on how to measure this stuff? Are you looking for flatness of the rear of the bellhousing, or parallelism between the engine face and rear of the housing, or both? How do you go about checking to verify everything is centered up perfectly?