But do you know of anyone actually getting that good? I am serously curious. I have driven an Impy SS, and man that thing hauled ***** (even the 3800 S/C's haul *****!) and am curious of the actual mpg numbers

Oh I know that LS1 numbers are fantastic, but I was curious on the 5.3 V8 used in Impy/Monte SS cars nowadays

Nope the 305TPI's were rated at that, and higher other years. 350 TPI's were rated at 245hp and 345 lb's of torque

 

I stand corrected!! I knew they had a high TQ rating, but knew that their HP rating was significantly lower. I thought there was closer to ~60 HP difference between the L98 and the LT1 though (mostly to do with the intake design? ). Although I don't trust that the 275/285 HP rating of the LT1's are exactly spec-on either??

 

The LT5 debuted at 375HP/370lbft (90-92), then was bumped to 405HP/385lbft for 1993.

 

Does anyone have the bore/stroke dimensions for the L98? Or any other dimensions for it at least? I knew the L989 made low HP #'s but I didn't think they were that low! W/ a TQ rating like that, I think the intake had a lot to do w/ it... like they said.. FAT intake runners, w/ a big plenum.

And yes, I did mean the LT5, I was just unsure of the RPO.

 

The mid 80s- early 90s L98 was 4.00 x 3.48 like every Chevy 350 (that was really a 350).

The problem is that it didn't breathe well, compared to a modern engine. The TPI has those tuned length intake runners that gave it a torque spike at peak torque RPM (3200?). But it
was all over at about 5500 RPM, and well down from the peak torque.

 

^ I wonder what happened to the Flue 91 or 92 Formula that GMHTP was building?

 

Lowest 305 TPI went ws 190ish hp after 85. From 87 to 92, the most powerful engine you could get with a manual was a 305 TPI equiped with the L98's camshaft. It made 210 in the first few years, but as the cam got a bit bigger, so did the hp. By 92, the 305 TPI with the G92 and 5spd manual was packing 230hp and 330ftlbs, not too far off L98 standards.
LONG LIVE THE LB9!!

 

It's cool Bro But EVERYONE underestimates the third gen. Know whats even funnier though (and even MORE unknown). The 305 TPI 5spd's were just as quick as the 350tpi's, if not quicker

**** ya! Even though they are rated at lower hp, the 5spd's kept right up with the 350's

 

Hooray Thirdgens. I too am a fan of the 305 / 5-speed, which is why I own one.

Back to the original topic, I don't imagine there will be a major switch away from cam-in-block designs at GM unless OHC and DOHC becomes cheap enough to produce in high volume.

Smooth engines are a must in Cadillacs and the like but obviously GM puts most of its v8s in trucks and SUVs.

 

Why even talk about cams??? There was talk a while back about camless engines where each valve is run by a servo... Talk about refinement! You could have a completely docile smooth running engine for everyday life and mileage and when you want to have fun you simply flip a switch and walla! a fire breathing dragon appears!!!

It's comming... just not for quite some time

 

I think there's a fine line between under-estimation and over-exaggeration though . I've seen a couple 3rd-gens at the track running low 15's, and the driver of one of them seemed thrilled with the time he got?!

Under-estimated?? Maybe . But that's still 2 seconds off my low 13-second LS1 .

 

Check the Third Gen section sometime. Many people are running 14's. Zepher, with a minor carb/distributor change, was running low 14's @ mid 90mph