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Stock-ish L82 in a '78. Currently has no smog and headers. I want to maintain decent vacuum,(of course). I'm in search of a higher performance camshaft with a some lope. I'll be replacing the stock heads eventually with 64cc and am in need of a trans rebuild in my TH350. I will also be replacing the torque converter with something of a higher stall speed.
Eventually my goal is 450hp. Any thoughts on which cam lift & duration for the application and which TQ stall speed?
Thanks, Mike
Been here, done that. My advise: save money and time and buy yourself a rebuilt create motor with your HP/TQ figures in mind. ATK has a wide choice of power ranges with well built short blocks and good components. Their prices are good, too.
2020 Corvette of the Year Finalist (performance mods)
2019 C3 of Year Winner (performance mods)
2016 C3 of Year Finalist
Originally Posted by reno stallion
383 These heads and this cam. these are the 185cc
Im running the Comp Cams high energy cam Version of that cam with solid roller lifters and 1.6 roller rockers. It doesn’t have good vacuum at idle but builds at higher rpm. I added a Hella 15 hg vacuum pump. I only hear it when I turn the key on but not once the motor starts......it is so ridiculously fun. I run a 15 lb flywheel and it revs up really fast.
The Solid flat tapped I had before at .501/ .510 was not really close in performance but had good vacuum and was nice and sounded good....same heads And 69 2.5 sweet thunder pipes but had Summit 2.5 rams horns manifolds. It was fast and had power but the difference is very apparent
Last edited by Rescue Rogers; Jul 17, 2020 at 11:20 AM.
on my 1980 L-82 I went with a Comp XE262H (previous owner switched to a L48 cam )along with ProMaxx 183 64cc cylinder heads and Performer 2101 , side mount headers through 2.5 pipes and glass packs on a zero deck 355 with flat tops . Currently switching the T350C to a 700R4 , stock 1600 stall converter works fine with the T350C and 3.08 gear in full lock up so I'm going with stock stall for the 700R4 too , Comp cam makes 18 inches of vacuum at idle and easily operates the headlights and other vacuum systems
here’s a link with Dart stock replacement heads with 1.94 valves, add 75 hp for 64cc aluminum heads https://www.compcams.com/xe262h
The L82's biggest issue is it's low compression. Hard to build power with that. That leads to new heads so you may as well buy good ones that flow well for more power.
L82's also have very low compression pistons. You'll need 10.4 or so for best power so that means new pistons and a full rebuild. Bore, etc. As long as you are doing all that you may as well spend a couple hundred more and make it a 383, for way more TQ.
Kind of hard to get to the power level you want piecemeal. Requires a full engine build. And the static compression ratio needs to be very carefully matched to the pistons and the heads and the camshaft to give you best power and a 8.3 DCR. Which means they all need to be done at the same time.
I'd say you could get to 350HP with a piecemeal approach. Over that requires much more planning and effort.
You could plan it all now, do the top end as one step. And then rebuild the shortblock later for the final step. With a 383 450+HP is pretty easy.
2020 Corvette of the Year Finalist (performance mods)
2019 C3 of Year Winner (performance mods)
2016 C3 of Year Finalist
I see 159 to 163....wish my car stayed that cold, mines right around 180 at temp....I see that there’s no fuel pressure So it’s a magic engine......maybe this snowflake is confused or it’s the 69 degree oil that he saw, which is obviously not connected either....
guess he’s just getting excited about nothing so he can feel good about himself...very confusing
Last edited by Rescue Rogers; Jul 17, 2020 at 12:26 PM.
2020 Corvette of the Year Finalist (performance mods)
2019 C3 of Year Winner (performance mods)
2016 C3 of Year Finalist
Originally Posted by reno stallion
I have ran this blower 383 engine in a hydro and now in this flat for 25 years it doesn't smoke or burn oil. The lake temp is 68°
And no thermostat
is it a drag boat.....have you seen finnegans garage on you tube? His drag boat has twin turbos..it’s stupid fast out of the hole and looks ALMOST as cool as yours
From: Las Vegas - Just stop perpetuating myths please.
Mike, there are a lot of U-tube videos by Richard Holdener that dyno test a lot of small block chevy combinations. One to note is he compares top dollar AFR heads to cheap imports and the dyno results show you get what you pay for.
Well IMHO a good street cam that still can make enough vacuum is gonna be less than 230 degrees duration at 0.050" lift. Now lobe separation angle affects this also but the better the heads the wider the LSA can be reducing overlap and increasing effective vacuum.
You have to make the decisions for heads and cam but if you have specific questions we can be more helpful.
Good luck.
BTW the L82 is a great short block to start with. It has forged pistons and forged crankshaft. Changing to those tighter 64cc chamber heads will add plenty of compression. Heads and cam and you should be good to go for close to your 450hp goal.
Last edited by cardo0; Jul 17, 2020 at 12:40 PM.
Reason: BTW
is it a drag boat.....have you seen finnegans garage on you tube? His drag boat has twin turbos..it’s stupid fast out of the hole and looks ALMOST as cool as yours
Mine is a 65 Schiada It is a family 4 seat flatty the hull is heavy. It has a 350 turbo trans with a converter another thing that's not supposed to work. It will only go 80mph. Finnegans boat is badass.
I have ran this blower 383 engine in a hydro and now in this flat for 25 years it doesn't smoke or burn oil. The lake temp is 68°
And no thermostat
I built an engine for a un
blown fuel flat boat it set the national record at the time of 8.5 seconds at 141.73 miles an hour.
Id love to find a boat like yours but I might get myself in too much trouble
Which camshaft? Which TQ?
. It will only go 80mph. Finnegans boat is badass.
