L48 engine mods - on the cheap
Thread Starter
Intermediate
Joined: Nov 2004
Posts: 28
Likes: 0
L48 engine mods - on the cheap
Hi guys, need a bit of advice, I have a stock L48, I have true dual exhaust which made a big difference to the performance.
What should I do next without breaking the bank ? and what HP/torque gains can I expect ? Also I know that I should probably change the cam, if so which one (mild) ?
Thanks in advance.
What should I do next without breaking the bank ? and what HP/torque gains can I expect ? Also I know that I should probably change the cam, if so which one (mild) ?
Thanks in advance.
Team Owner
Joined: Aug 2006
Posts: 24,125
Likes: 15
From: Columbia Missouri
There are a few things that can be done, but you won't see big gains until you spend the big money. An after market intake and proper carb tune will get you some small results, and a cam and lifter combo will also help. The big change will be when you swap to some better heads.
A cheap head swap option that a few guys have had good luck with is a used set of Vortec heads. Add to that a manifold that fits the Vortec heads, and a good cam and lifter combo...you won't break the bank and you'll get better results.
A cheap head swap option that a few guys have had good luck with is a used set of Vortec heads. Add to that a manifold that fits the Vortec heads, and a good cam and lifter combo...you won't break the bank and you'll get better results.
Instructor
Joined: Feb 2006
Posts: 105
Likes: 0
From: Houston Texas
Another low cost option (if you have not done this) is to spend the time making sure the car is tuned properly. Not just the cap and rotor - but setting the distributor up for 36 deg all in by 3000 rpm. Replace all the old vacuum hoses. I did this on my stock motor with Performer manifold, duals, and new carb and it woke the car up quite a bit from what it was. Maximize what is there first and then you will have a better idea of where to go next. Of course with the low power we started with there is nowhere to go but up - 
Last edited by Sweet L82; Mar 18, 2007 at 12:56 PM.
Abby Normal
Joined: Dec 2001
Posts: 53,288
Likes: 92
From: Press "2" for English
these threads always worry me when i read them. first, what is the condition of the engine now? especially the bottom end.
i agree with all about how to get more mojo but i always question the wisdom of throwing any more pressure (i.e. power) at a tired bottom end. if it's an orginal block you can pretty much bet the tops of the cylinders are going to be open like a ***** house in the red light district. whatever you would gain with a fancy set of heads and a lumpy cam will be cut in half by the blowby through the rings. not to mention the burning oil.
while i think Dboy has a good idea, the first thing i would do is check the cylinder bores with the heads off. if you have a ridge large enough to catch a nail on, you might as well pull the engine and do it right. otherwise, you'll just be doing it again in a couple years. this i know.
i agree with all about how to get more mojo but i always question the wisdom of throwing any more pressure (i.e. power) at a tired bottom end. if it's an orginal block you can pretty much bet the tops of the cylinders are going to be open like a ***** house in the red light district. whatever you would gain with a fancy set of heads and a lumpy cam will be cut in half by the blowby through the rings. not to mention the burning oil.
while i think Dboy has a good idea, the first thing i would do is check the cylinder bores with the heads off. if you have a ridge large enough to catch a nail on, you might as well pull the engine and do it right. otherwise, you'll just be doing it again in a couple years. this i know.
Team Owner
Joined: Aug 2006
Posts: 24,125
Likes: 15
From: Columbia Missouri
Very good advice.
