newc3

1977 stingray l48 350 automatic...would like to add more power to the stock engine, what do I need? would like more hp and make it sound louder and meaner lol

in the mean time - here's a video of my buddies doing a test drive after we got it running, nsfw as there's an F-bomb or two in there

newc3

would these fit ? are they a good deal?

http://www.kijiji.ca/v-engines-and-e...ationFlag=true

http://www.kijiji.ca/v-engines-and-e...ationFlag=true

Conrad Celinski

If you're looking for a lot more performance then I wouldn't go for either of those engines. Look for something in the 350-400hp range for a little bit more do a search on the forum. You'll find PLENTY of people looking for more power out of an l48 and plenty of engine swap threads. Oh, and as for meaner sound and performance...make sure you go with a good set of full length headers and true duals with some new mufflers. That'll liven it up a little and your muffler choice will match the sound to your liking

jb78L-82

If you are looking for more HP from your l-48, by far, the biggest bang for the buck would be a dual exhaust with headers but I definitely would not go for LTH's on a stock motor on the street-I have done that route on other cars.

My 78 stock L-82 (220 Stock NET HP) with Mcjacks shorty headers and 2.5 inch duals produced 233 RWHP on the dyno which is about 275 NET HP(15% RWHP to NET)-a 42 HP increase-with a leaky #6 valve. Karol on the forum produced 248 RWHP with his 78 L-82 with a performer intake/Cam of unknown origin, 2.5 magna flow duals with stock exhaust manifolds-no headers, which is about 290 NET HP-70 HP increase.

The CC magnaflow 2.5 inch duals with Block hugger headers is a great deal. Skip the LTH headers on a Stock L-48-it will do little for your power gains versus shorty's for a stock street car-Not worth the hassles of heat issues, noise, engine clearance, road clearance, etc.

jb78L-82

Remember that both of these engines are rated as GROSS HP, not Net, not RWHP. The 260 HP engine looks to be an L-48 clone, barely. The 290 Gross HP is NOT even a stock L-82 which about 315-320 Gross HP. The 290 HP looks to have an L-82 cam-.450/.460, 222 duration BUT ONLY has a compression ratio of 8:1 versus the L-82's 9:1. That cam with a 8:1 compression will make the engine a dog-stay away! The heads use the small valves as well.

I am today about to start dismantling the top end of my L-82 with 66,000 miles on it. Going with AFR 180 65 CC heads and a Howards roller cam-.525/.525, 219/225 duration LSA 110 which will should net me a BIG increase in power BUT my engine is an L-82, not an L-48. I am doing the work myself and am all in for about $2,500 BUT you can do substantial improvements on your engine using much less expensive heads-cast iron, with a flat tappet cam probably for about $1,200-$1,500.

Just some ideas!

resdoggie

I would put a set of aluminium heads on selected to increase compression at the same time provided your current engine is up to it. Put in a cam and a freer flowing exhaust.

77Driver

I purchased the 2.5 in dual exhaust manga flow muffler kit from corvette central but left the stock rams horns on. It made a noticeable difference. My question is how is the oil pressure on your L48? What are your plans for the car? My plan is to leave the bottom end alone and put in an Edelbrock Performer/Estreet package headers and a new carb. I've had the car for 13 years and the engin was rebuilt sometime before I got it I suspect and it doesn't burn much oil. The plugs are clean and cylinder pressure is good. I know I don't have the technical skills to match up a heads cam and intake so I'm partial to paying extra to get something like that. I think summit racing has some good combos too.

MrJlr

Heads, cam and exhaust.
Oh, and a good tune up

scottyp99

1). Re-curve distributor:

http://www.jegs.com/i/Mr-Gasket/720/929G/10002/-1

E-mail Lars Grimsrud v8fastcars@msn.com and ask him for his paper on How To Set Timing. Follow the instructions, and your car's ignition timing curve will be optimized for performance. It will make a difference that you can definitely notice in the seat of your pants. Best 9 bucks you'll ever spend.

2). Dual exhaust. I'm with jb78L-82 on this one. The Corvette Central exhaust kit is a good deal.

3). Pick up a used Edelbrock Performer 2101 intake manifold. You can find them on ebay or craigslist for 50 bucks. For 50 bucks, it's worth doing. A little more power, and a little less weight on the front end.

4). Carb tune. When you e-mail Lars, ask him for his paper on How To Tune A Qjet. (I'm assuming you have the original Qjet carb.)

5). Past all this, you are looking at a cam & head swap.

6). Last but not least, chrome valve covers. They add at least 5 horsepower!

This question is asked so often, there should be a sticky for it.

Scott

wilcar

Do the true dual exhaust, recurve distributor and tune the qjet per Lars instructions. You need a cam that will help boost your low speed cylinder pressure with your 8.0 c.r. use a short duration cam on a 108 lsa like the Isky 264 mega cam which has 214-214 @ .050, .450 lift , 108 lsa. I had a 76 L82 and used the 264 cam along with the mods listed above and had much better low and mid range punch. I even used the stock valve springs and kept the stock exhaust manifolds but headers would have yielded more power. 264 had a nice little lope to it!!

REELAV8R

This sounds like it might work pretty well with the low CR of the original bottom end if you decide to do a cam swap. You would end up with a DCR around 6.64. Still low, but better than stock.

scottyp99

It's so cold you can see these guy's breath, and they are driving around on the ice-covered roads with the T-tops off! And if you think there is anything strange about that, then you are just not a true hot-rodder. The only way this video could have been any cooler is if the hood was off.

Also, while watching the video, a thought struck me: I want a car that drives like that on dry pavement!!!!!

Scott

newc3

ya it was about -20 C out there and he was holding the gopro out the t-top with his bare hand!!!

newc3

lot of good ideas thanks guys. i only posted those ads because they were cheap, i will stay away!

is 3grand enough for a good engine? or better to put into the l48? 3k is all i have
and my mechanic is 20 bucks an hour.

scottyp99

My momma told me...ya gotta shop around! That first engine you posted a link to was for 1800 bucks. You can get the exact same engine, same part number and everything for 1500 bucks, free shipping, from Summit Racing:

http://www.summitracing.com/parts/na...FcZZ7AodQgsAsg

It's basically a brand new version of the engine you have in the car now. if your engine is tired, it could be a good deal, depending on what you want as a final product. This new engine, with headers, dual exhaust, re-curved distributor, and a Performer intake manifold, would be pretty peppy, and the 36 month warranty would still be valid.

Do a compression test on your current engine, and see what kind of compression it's making. You may be better off souping up that engine if it's still in decent shape.

Scott

Mod75

On the cheap?
Find some older heads or mill yours to get some compression.
Re-curve the dist, duals.
Keep it simple.
Enjoy.

garygnu

I am with scotty on upgrades .or do a 383 stroker ,using your current short block .shop around for a good engine machine shop locally .sbc chevys are are easy to R&R in a vette .some beer and pizza will all you need to pay some pals to help you .you can find good heads for $1000.

newc3

should i order this one? compatible ?

http://www.summitracing.com/int/part...3ct1/overview/

scottyp99

From the bottom of the page, notes:


This engine requires a 400 cid weighted harmonic balancer (external balance), and a late-style 350 cid (1-piece rear main) weighted flexplate/flywheel.

So, you'll need a new flexplate and harmonic dampener. Other than that, it should bolt right in. This engine is externally balanced, which I don't really like. Another issue that you would need to verify is whether the a mechanical fuel pump will work with this engine, because it's a one piece rear main seal engine. Many of them did not come from the factory with the necessary machine work to allow the mechanical fuel pump to work, because they were installed in cars that had in-tank electric fuel pumps. A phone call to Blueprint Engines would clear this up easily.

If you want good advice on installing an engine with a power level much different than your stock engine, You will need to provide the following: Diff gear ratio, transmission type and model, torque converter stall speed (if applicable).

Something to consider might be to make some inexpensive hop-up mods on the existing motor for about a grand, (dist re-curve, dual exhaust w/ headers, used Performer intake) and spend the rest on an overdrive transmission swap. With a 700r4 or 2004r transmission, not only will you get the advantages of having an overdrive gear for cruising down the highway, but the first gear ratios on these transmissions are lower than on the th350 and th400 transmissions that came in these cars. That will give you a little more kick in the pants in first gear, and will make for a fun driving experience. One thing to be aware of with these transmissions, though, is that the low first gear comes at the cost of having pretty widely spaced gears, which means that the engine in front of it should have a nice, wide torque curve for best performance. That means stay away from "bottom of the page" type cams and such.

Here is a link to that engine on Blueprint's web page, it give a little more detail:

http://www.blueprintengines.com/inde...1-engine-specs

Scott

MrJlr

http://forums.corvetteforum.com/c3-t...int-383-a.htmlI just installed that engine. So far I'm very happy with it.
Read about it here

Edir: link is above the quote. Tablets paste funny !