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1969 L78 396 375 HP Dyno Test
Thought some might be interested in this build: factory 1969 L78 396 375HP. 3.760 stroke std, 4.134 bore, Speedpro L78 pistons, sealed power moly rings, resized 3/8 dimple rods, factory L78 oil pump, factory oil pan, factory GM card board tube L78 L72 cam, installed @ 108, isky lifters, factory pushrods, factory rocker arms. 4.250 bore steel shim head gaskets, factory M head bolts, 840 heads, bronze guides, race valve job, CCs set to 108, factory 163 intake along with the factory L78 carb, factory L78 points dist setup by Harold Bettes. Tested with 2 inch headers into 3 inch mufflers, gas used was VP C-12. Basically very close to a factory L78.
Corrected HP 4500 379.8 4600 382.3 4700 385.5 4800 389.8 4900 395.2 5000 406.3 5100 415.3 5200 423.4 5300 431.4 5400 438.6 5500 444 5600 446.5 5700 451.7 5800 452.3 5900 451.2 6000 453.9 6100 454.9 __________________ |
Re: 1969 L78 396 375 HP Dyno Test
Thats wicked pissa
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Re: 1969 L78 396 375 HP Dyno Test
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: AMANOCC</div><div class="ubbcode-body">Thats wicked pissa </div></div>
OK, thanks......I think. |
Re: 1969 L78 396 375 HP Dyno Test
Factory jetting?
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Re: 1969 L78 396 375 HP Dyno Test
I love it
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Re: 1969 L78 396 375 HP Dyno Test
Nice work as usual. [img]<<GRAEMLIN_URL>>/beers.gif[/img]
Almost mirrors the L78 I built for Donnie Cornelis back in 2012. (Donnie's had a touch of headwork done but we never got the chance to really lean on it, ran out of time on the dyno.) It's a shame so many people are so quick to disparage these baby rats. With a little refinement 500+ HP is in the bag. [img]<<GRAEMLIN_URL>>/biggthumpup.gif[/img] |
Re: 1969 L78 396 375 HP Dyno Test
At what RPM did it actually make the advertised rating of 375? [img]<<GRAEMLIN_URL>>/grin.gif[/img]
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Re: 1969 L78 396 375 HP Dyno Test
"Tested with 2 inch headers into 3 inch mufflers"
I assume this WILL NOT be your street set-up? |
Re: 1969 L78 396 375 HP Dyno Test
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: VintageMusclecar</div><div class="ubbcode-body">Nice work as usual. [img]<<GRAEMLIN_URL>>/beers.gif[/img]
Almost mirrors the L78 I built for Donnie Cornelis back in 2012. (Donnie's had a touch of headwork done but we never got the chance to really lean on it, ran out of time on the dyno.) It's a shame so many people are so quick to disparage these baby rats. With a little refinement 500+ HP is in the bag. [img]<<GRAEMLIN_URL>>/biggthumpup.gif[/img]</div></div> The wife and I have had two 396 power cars (67 SS Chevelle & 69 Pace Car - both three pedal). They ran just fine for a "baby rat" ... TAZ |
Re: 1969 L78 396 375 HP Dyno Test
Just don`t make the same first test drive video as Donnie made.....Priceless [img]<<GRAEMLIN_URL>>/biggthumpup.gif[/img] [img]<<GRAEMLIN_URL>>/burnout.gif[/img]
Dan |
Re: 1969 L78 396 375 HP Dyno Test
Long Live L78's! The unsung hero and road warrior of the Big Block Kingdom.
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Re: 1969 L78 396 375 HP Dyno Test
Nice numbers on that L78. [img]<<GRAEMLIN_URL>>/biggthumpup.gif[/img]
I have a similar build that is nearly done, although it is .070 over, with a bit more aggressive cam. I hope to make a little more power, but the dyno will tell. |
Re: 1969 L78 396 375 HP Dyno Test
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: bbbentley</div><div class="ubbcode-body">Long Live L78's! The unsung hero and road warrior of the Big Block Kingdom. </div></div>
You`re my Unsung Hero [img]<<GRAEMLIN_URL>>/biggthumpup.gif[/img] Dan |
Re: 1969 L78 396 375 HP Dyno Test
So is it safe to say that these cars when new had this kind of HP with a set of headers bolted to them?
Very impressive!! I had always heard that the 69 Z's were just as fast when geared properly. |
Re: 1969 L78 396 375 HP Dyno Test
In as-delivered condition with manifolds, I'd say the factory 375 HP rating was fairly accurate. Headers are typically worth ~30 HP on these engines.
Read this and note what JRSully stated on the last page. |
Re: 1969 L78 396 375 HP Dyno Test
Eric,
I may need to call you sometime about my stumbling issue on my 69 L78. Love the stock look but with headers! They just make these old motors run so much better. |
Re: 1969 L78 396 375 HP Dyno Test
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: L78racer</div><div class="ubbcode-body">Factory jetting? </div></div>
X2 Also what was the total timing? Great numbers! |
Re: 1969 L78 396 375 HP Dyno Test
My 70 L78 Nova with manifolds and stock exhaust with crossflow muffler is disappointing.
On the 67 L78 with headers and a Flowmaster system is like Mr Toads wild ride. |
Re: 1969 L78 396 375 HP Dyno Test
Headers worked well on this engine when they were open. Seemed like it would rev forever.
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Re: 1969 L78 396 375 HP Dyno Test
L78s MUST have headers to get everything out of them, IMO. Timing all in by 3k. I have this set up in my Nova and it just screams and has stayed VERY reliable for the past bunch of years, only deviation from stock are roller rockers, no ported heads, no larger valves, orig 569 flattie intake, orig Holley 4557, orig cam, orig compression, bored 30 over. do have a Pypes exhaust system with transverse muffler mounted in stock location. I think dyno'd at about 425 @ 5700, right about where it should be
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Re: 1969 L78 396 375 HP Dyno Test
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Survivor 69/Z28</div><div class="ubbcode-body">So is it safe to say that these cars when new had this kind of HP with a set of headers bolted to them?
Very impressive!! I had always heard that the 69 Z's were just as fast when geared properly. </div></div> Never saw a street Z that was faster then high 12s.Most needed a big cam to go that fast.I got tired of running them with my L78.Of course they were never intended to be drag cars. |
Re: 1969 L78 396 375 HP Dyno Test
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: JRSully</div><div class="ubbcode-body">L78s MUST have headers to get everything out of them, IMO. Timing all in by 3k. I have this set up in my Nova and it just screams and has stayed VERY reliable for the past bunch of years, only deviation from stock are roller rockers, no ported heads, no larger valves, orig 569 flattie intake, orig Holley 4557, orig cam, orig compression, bored 30 over. do have a Pypes exhaust system with transverse muffler mounted in stock location. I think dyno'd at about 425 @ 5700, right about where it should be </div></div>
Is there space for the back drive rod with the headers? |
Re: 1969 L78 396 375 HP Dyno Test
Not in the old days. Maybe the header people figured it out by now? Do you need the reverse lockout rod?
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Re: 1969 L78 396 375 HP Dyno Test
[quote=Survivor 69/Z28]So is it safe to say that these cars when new had this kind of HP with a set of headers bolted to them?
Very impressive!! I had always heard that the 69 Z's were just as fast when geared properly.[/quo Nope! Maybe with a plug wire pulled off they were. |
Re: 1969 L78 396 375 HP Dyno Test
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: [email protected]</div><div class="ubbcode-body">Not in the old days. Maybe the header people figured it out by now? Do you need the reverse lockout rod? </div></div>
Its good for the reverse lights and column lock but thats it. Car is bone stock. |
Re: 1969 L78 396 375 HP Dyno Test
would love to have some kind of operational reverse lock out rod, as Steve mentioned, would be good for reverse lights. Anybody fab something up to achieve this.?
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Re: 1969 L78 396 375 HP Dyno Test
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: JRSully</div><div class="ubbcode-body">would love to have some kind of operational reverse lock out rod, as Steve mentioned, would be good for reverse lights. Anybody fab something up to achieve this.? </div></div>
I remember someone either on this site or the CRG flipped the bellcrank lever and reversed it somehow and got it to work. |
Re: 1969 L78 396 375 HP Dyno Test
part of the "throw away" package in the old days.
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