LT1 compared to L79

[black69]

Had innocent question: Are the LT1 and L79 motors close enough in idle behavior that if you could get an auto with one (LT1=yes?), why not the other. I heard a L79 could never keep an automatic happy, so thats why one was never offered, but is an LT1 that much different really at idle in gear? same HP with just a little more displacement?
curious on how different they really are.
-bob

[YENKO DEUCE REGISTRY]

I think they are night and day, LT1's rock and the L79's are junk! JK of course, [img]<<GRAEMLIN_URL>>/grin.gif[/img]

Good question, and one that my ole buddy Neal and I debated at length. I was on the LT1 side, but had never driven an L79 where Neal owned 4 Yenko Deuces and a '66 L79 Nova. He felt that the L79 might be the better combo, even given the small carb and hydraulic cam - just short on cubes.

[kwhizz]

In 66 I bought a new L-79 Nova.....with just slicks and headers the car ran a best of 13.12.........3:73 and a close ratio...........

Ken

[Mr.Nickey Nova]

The L79's if tuned right with a good driver would beat up on the big block cars including some Hemi's.I was told this by someone who street raced back in the day with a L79 ChevyII,also read it somewhere too.

[Bill Pritchard]

Keep the time frame in mind here...in 65 and 66, when the L79 was at the peak of its popularity, the most popular automatic in a Chevy was the Powerglide. The T400 was a new transmission at the time, and restricted to use behind the tamer big blocks (which were also 'new'). I feel pretty confident in saying that an L79/PG combo would not be the hot setup [img]<<GRAEMLIN_URL>>/no.gif[/img] , which could be the major reason it was never offered. By 1969, when automatics became relatively common behind high performance Chevy engines, the L79 was history.

[Jeff H]

If you're talking stock, I don't think you can really compare a solid lifter engine to a hydraulic lifter engine, especially idle quality, vacuum and putting behind an auto trans.

[jbsides]

I'm with Jeff. In '71 I was turning in 14 flat with a bone stock '70 Z LT-1 T-400 combo, went to slicks and headers for consistent low 12's.

JB

[markjohnson]

I recently sold an original 1968 Nova L-79 327-325 HP 4-Speed that I had purchased from the original owner. It still had it's original motor, tranny and 3.55 gear'ed 12-bolt. Even though the L-79 was tamed down a bit in 1968 with a Q-Jet/cast iron intake, it still had all the good stuff underneath: 11.00:1 Compression, 2.02 heads and that famous #151 camshaft. It even came with the original Blue Streak slicks in the trunk that were purchased for it when it was brand new! It's kinda like a prehistoric Yenko Deuce! Anyway, I would have loved to turn it into a Pure Stock car and seen just how fast it would have been capable of. It would have been a great race between a '68 Nova L-79 vs. '70 Yenko Deuce LT-1.

[black69]

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Jeff H</div><div class="ubbcode-body">If you're talking stock, I don't think you can really compare a solid lifter engine to a hydraulic lifter engine, especially idle quality, vacuum and putting behind an auto trans.</div></div>

wouldn't hydraulic vs solid lifter be irrelavant at idle? doesn't the lifter type difference come in to play at the top end of the rpm curve (solid lifters win). I am still stumped on why some say a L79 can't idle smoothly while in gear with an PG (the main reason it was not offered). I agreed with that until I noticed the LT1 came with autos, so thus the questions above. GM offered a 409 340hp (not a performance slouch) with a PG, as one example that was 10HP down from a L79. I picture a L79 to be hard to manage to keep at idle at lower RPMs. The LT1 has to be happier down in the lower RPMs when in drive in an auto application.
The vacuum difference I do not get at all between the 2 engines.

[SuperNovaSS]

I don't believe it has anything to do with the differences between the L79 and LT1 or hydraulic vs. solid lifters. The fact is, there was not not a production trans ready for the higher shift points and heavy duty usage to readily handle the L79. Couple that with the fact that the low shift point between first and second would take the L79 out of its power band and its a recipe for low performance and warranty work due to self shifting and back yard tinkering.

The torque converter would allow the engine to idle with no problem no matter what the cam was. It is the fact that it was not logical to put a low RPM shifting 2 speed auto behind an aggresive V8 that stopped the L79 from being coupled with an auto. I for one am glad it never was.

Jason