Carb/exhaust question
Thread Starter
3rd Gear
Joined: May 2012
Posts: 3
Likes: 0
Carb/exhaust question
I recently picked up 74 stingray with an original l48 (rebuilt a few years ago) and I am looking for some ways to increase power. I'm a novice but have some handy friends. One has recommended replacing the stock carbureter as an easy project to increase horse power. Any suggestions on one?
I'm also looking for a recommendation on exhaust system? Im in Cali but pre smog year. Went by a shop today and he said stick with 2 inch pipes and a new flow master would sound better but I won't see any increase in performance.
I appreciate any tips!
I'm also looking for a recommendation on exhaust system? Im in Cali but pre smog year. Went by a shop today and he said stick with 2 inch pipes and a new flow master would sound better but I won't see any increase in performance.
I appreciate any tips!
Team Owner
Joined: Jan 2006
Posts: 37,637
Likes: 3,114
From: Crossville TN
There is no "functional" reason to change carbs. You may need to rebuild yours, but that costs about $30 and 4 hours of your time (for the first one). The Q-Jet will equal [or better] any other carb on performance and it is the best of the bunch on efficiency (economy) under normal driving conditions.
To increase performance, tune the carb and distributor {re-curve it for performance}, which is essentially FREE hp; then change heads, cam, and exhaust on existing engine. Just make sure the heads and cam are compatible and will work together well.
To increase performance, tune the carb and distributor {re-curve it for performance}, which is essentially FREE hp; then change heads, cam, and exhaust on existing engine. Just make sure the heads and cam are compatible and will work together well.
Last edited by 7T1vette; May 8, 2012 at 08:16 AM.
Melting Slicks
Joined: Jul 2009
Posts: 3,264
Likes: 3
From: Vero Beach FL
There is no "functional" reason to change carbs. You may need to rebuild yours, but that costs about $30 and 4 hours of your time (for the first one). The Q-Jet will equal [or better] any other carb on performance and it is the best of the bunch on efficiency (economy) under normal driving conditions.
To increase performance, tune the carb and distributor {re-curve it for performance}, which is essentially FREE hp; then change heads, cam, and exhaust on existing engine. Just make sure the heads and cam are compatible and will work together well.
To increase performance, tune the carb and distributor {re-curve it for performance}, which is essentially FREE hp; then change heads, cam, and exhaust on existing engine. Just make sure the heads and cam are compatible and will work together well.
Just about every performance modification has a trade off. Be aware of them before you start making them. Headers will increase horse power and require exhaust modifications . They may also require different brackets for mounting A/C and your alternator. Then there is the heat factor, they produce more heat.
One change leads to another.
Thread Starter
3rd Gear
Joined: May 2012
Posts: 3
Likes: 0
Thanks guys, I was reading about carb rebuilds last night and am going to give that a shot. As for the exhaust it sounds like I need to figure out what I'm going to do with the heads first. I think I can tackle replacing those but a friend warned me about screwing up my engine compression?
Team Owner
Joined: Jun 2000
Posts: 38,923
Likes: 1,481
From: Southbound
Cruise-In II Veteran
Why not keep the car stock? After all, it has somehow managed to survive all these years with no major changes made to it. The stock 195hp L-48 will take you anywhere you want to go without problems.
Le Mans Master
Joined: Jun 2004
Posts: 6,231
Likes: 65
From: Seattle WA
St. Jude Donor '14
Have the Q-Jet rebuilt and tuned by a professional shop - there's nothing overly complex about doing it at home, but tasks that will need to be done such as rebushing the main throttle shaft are best left to the pros. At the very least, get the parts from one of these places and don't try to use the garbage "one size fits all" Q-jet rebuild kits.
http://www.cliffshighperformance.com/
http://www.smicarburetor.com/
From there, exhaust is your next step along with a mild cam upgrade and timing set replacement - both fairly inexpensive. Last step is a dyno tune...which will be the best $300 or so you ever spend. You'll end up with the best the engine can deliver - which is pretty good
Otherwise, you'll need to dig deeper into the engine which - as you note - is going to compete with other things that need attention. Figure on $1,500 or so for a mild head swap...if that's in the budget, then let's chat
http://www.cliffshighperformance.com/
http://www.smicarburetor.com/
From there, exhaust is your next step along with a mild cam upgrade and timing set replacement - both fairly inexpensive. Last step is a dyno tune...which will be the best $300 or so you ever spend. You'll end up with the best the engine can deliver - which is pretty good
Otherwise, you'll need to dig deeper into the engine which - as you note - is going to compete with other things that need attention. Figure on $1,500 or so for a mild head swap...if that's in the budget, then let's chat
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Melting Slicks
Joined: Sep 2004
Posts: 3,221
Likes: 665
From: Northeast
Before you start tearing down the carb, who told you that you have a carb problem? It could have been properly rebuilt last year. What is happening to make you think it needs a rebuild?
Also, you said the engine was rebuilt a few years ago. Have you been to a dyno or have any information about the rebuild. He might have done what people have said to do in this thread. You need more info from the PO.
Also, you said the engine was rebuilt a few years ago. Have you been to a dyno or have any information about the rebuild. He might have done what people have said to do in this thread. You need more info from the PO.
Melting Slicks
Joined: Jul 2009
Posts: 3,264
Likes: 3
From: Vero Beach FL
I am with Mike on this one. My 71 is a non-matching #'s has headers, aftermarket carburetor, intake, distributor, radiator only because it did not have any of those parts (I mean like nothing was there) when I got it. If your car is original and running it would keep it that way. Just my thoughts and I am an old hot rodder at heart. 
Racer
Joined: Nov 2004
Posts: 485
Likes: 1
From: Oakville ON
original l48 (rebuilt a few years ago)
Your first step should be to find out what was used in the rebuild, especially cam and pistons. To prove he spent the $ the PO should provide the build bill. That should list parts used. If he can't, find out where the rebuild was done and they may be able to tell you what they "normally" use. They may even have the build sheet on fille.
