I was racing and saw this.....

[Ron Earp]

I went down to Roebling Road this past weekend to poke holes in my 260Z pistons (yes, it is a bad year for Ron and racing).

After fully accomplishing that goal I started drinking beer. Lo and behold a good looking woman comes crusing by on this (I know, as improbable as that sounds in an SCCA paddock it is 100% true and I'd only had two beers, I even got witnesses) except hers was even better and had wheelie bars. I knew then I had to have one!

You can find these things here:

Cooler Croozer, Cooler Cruiser - The Motorized Cooler, Awesome for Tailgating from Baron Bob and Wonderfully Wacky

Cheaper than racing and as far as I can tell a hell of a lot more fun!

R

[chuck smith]

saw several of those at the Walter Mitty historics this weekend

[Scott Calabro]

Burn't pistons or cooler cruisers ?

[chuck smith]

several of both

[Big-Foot]

Went a tad too lean there Ron... Sad sight... Tough beginning for your season!

I raced this last weekend at a NASA race at Iowa Speedway (NASCAR Track / Roval) with an ill handling, poorly braked Porsche 924S. Managed to stay out of trouble and didn't bend anything up but it was a frustrating time. At least the car turned left reasonably well.. Just wouldn't stop or turn right.. It's getting all new brakes, springs / torsion bars, shocks and sway-bars this week..

I hope that things will turn around soon for you ...

[Pete.]

By the mark in the top of the piston it looks like a valve might have touched also.
Bad luck Ron, you have had a tough year.

I love the bar stool cooler though, imagine having a race with those, the rules could state that each driver would start with with a cooler full of beers and be able to lighten his buggy by drinking his way through the cooler as he went.
You would have piss stops instead of pit stops and the last few laps would be hilarious.......

I doubt it would get sanctioned though.

[Ross Nicol]

Snap Ron
I did the same to my first Z motor. Is it piston 4 or 5? according to my Z expert the rear of the inline 6 motor doesn't cool as well as the front.He told me to come in if it started pinging from detonation and stupidly I stayed out. The result was a lot of blue smoke in the mirror and the end of my day. I was shown how to read the plug colours and after the SU carbs were set correctly, all was good. My 2nd motor was a lot better anyway, a proper race motor. Another good tip for the Z is to put a white marker across the front of the harmonic balancer and check for loosening after each race.The crank has resonances that shake the balancer loose. One positive Ron they are cheap motors. I'm racing the 40 next weekend.
Ross

[Ron Earp]

It is pistons one and two, and two is the one with zero compression.

a well known Z motor builder told me that #2 frequently runs hotter than #1 and #3 due to the intake manifold design and I believe him. If you look down it from the bore the port to #3 is very open, #1 partially shrouded, but #2 is almost obsecured. The air/fuel mixture will be different in each one but leaner in #2 as the air and fuel has to make a relatively sharp bend and some separation will occur.

Add to that fact that this particular car has EGTs in #1 and #6, tuning for those cylinders, and you might have a lean condition in #2 at high RPMs. It was fine to 7k, but at this one track I was avoiding a 3-4 shift and riding 3 a bit to long, to about 7500 RPM. And I bet it got lean in that range. Bang.

You can bet I'll switch the EGTs to #2 and which ever cylinder on the back three has the more shrouded port when it goes back together. Block is out, engine apart, and will go to the machine shop guy (a good local Ford builder and racer). Another Z racer is going to loan us his torque plate so we can bore while torqued up.

Your white mark trick was just told to me by another dude about 2 days ago on the IT Forum - thanks for sharing that too. My front pulley is on the way out as the rubber coupling section, that thin part, is about gone and the pulley has a bit of wobble.

They are sort cheap - about $600 in parts with all new pistons, good bearings, etc. plus some other bits I don't need but am replacing anyhow.

Good luck with the 40 in the race, don't hold those gears too long. Is this with the new motor?

Ron

[Ian K]

Yep, my mechanic also raced a sweet 280Z - 1 & 2 are known trouble spots. I
threw a rod on #2 in my 240Z.

Ian

[TimOz40]

Gosh.
Pricey go-kart with beer = pissed'n'broke
Z motor gone bang = piston broke

Think i'd prefer option (a)

[Jac Mac]

Might pay you to look into some decent dowels to locate the cyl head & particularly the Head Gasket, looks like the fire ring has been hanging over the edge of the bore in the region of the valve notch, if that is the case that may be the real culprit in your engine failure.

Jac Mac

[Ron Earp]

May need to look into that, good advice. I've got to get on it this week and get it over to the shop. I'll get a lot more pictures and see what you think.

R