You do this regularly?

 

I shifted the cam only at 6700-6800. Ran it like that for 10,000+ miles and never had any problems. Hit the 7k ecm limiter a few times too

 

Do y'all guys who spin up to 6400-6800 still use the stock timing chain?

 

No, cloyes double roller for me.

 

I still have a stocker, :-(

 

LT4 extreme duty here

 

I've hit the 7,200 rev limit on mine a few more times than I'd like to. I've made quite a few passes where I've had my shift points at 6,800 without a problem. The only thing changed from stock in the bottom of the engine was the oil pump, Melling HV55, nothing in the rotating assembly was touched. As for a timing chain I'm running a Roll Master true double roller... best damn chain I've ever used on ANY small block I've run to date. The valve train was also set up for the rpm as well... fresh springs, geometery checked, and a rev kit. All this was on a 80,000+ miles engine.
Turning ANY stock bottomend engine up this high and it surviving is actually a bit of the luck of the draw so to speak (with out going into them and checking tolerances). Some of these engines come out of the factory put together VERY well and on others... you'd swear the workers tied one on a bit too much the night before, LOL.
Steve...

 

I've spun mine to 6,900 on the dyno. Power didn't fall off at all. I usually shift at 6,600 though.

 

So is the stock oil pump incapable of providing adequate pressure up at those rpms?

 

i also have a LT4 extreme duty and i have smacked into my 6800 rpm red line a few times. For me, at the end of the track i either have to stay in the gas in the 3rd gear for the last part of the track or just barely get into 4th gear. When i stay in 3rd gear and take it all the way up to 6800, my mph goes up by ~1mph or so. When i just grab 4th i'm a little slower. 4.10's should fix this problem, hehehe.


trav

 

During racing season I'm racing every weekend, that's just a tad over 40 weekend's a year. 6400 is the norm for me. Pulled the motor out this winter bearings and crank look great since we tore it down two years ago.

 

I used to spin my stock heads, cc306 to 6600 with 100K miles on it (upgraded valvetrain)

 

I took mine up to 6500 RPM on a chassis dyno after I installed TEA stage 3 ported LT1 heads, XE 230/236, and a rod bearing let go on the first pull. It was OK for 3K miles street driving before this. The cam/heads peaked at 6300.


Nick