My LG4 is about 7000 miles shy of hitting the big 100k. It's not smoking and the only other thing is the oil pump seems to be wearing out, which I'll replace while I'm changing the cam. I'd like to just put a cam in it now and not yank the motor and replace with a 350 because it'll be more expensive and I'll be putting a brand new crate motor in it when I graduate college. (5 years)

 

You run into the big "While your in there" issue though...
"While your in there," you should really rebuild the top of the motor. Five years is a long time for a motor to last with old parts and an aggressive cam.

 

SWEET Corvette!

 

I wouldn't think it would be a bad idea, just make sure to get lifters too. A timing chain would be a good idea too, the chains usually last about 150k. How many miles do you put on the car a year? And make sure not to get too big of a cam. Nice Corvette by the way.

 

i did my cam swap at 107k, no worries, no leaks, no problems, lotsw more power

later
tim

 

how much more power did you notice with the LT1 cam? all this talk about it helping so much is getting me excited lol hell for the 50$ it costs id be happy with 10hp from it and i here it helps more than that...also can you rev higher now?

 

I've heard in the past that by just rebuilding the top end that you are more likely to blow a piston ring or something, is this true?

 

No. At least, not in the 1300+ miles I've put on mine with the mods in my sig on a 143,600 mile shortblock.

 

I did a cam swap years ago in my old TA (305 LG4, Auto) at 180,000 miles. My teacher in automotive school thought I was nuts and told me I would quickly "blow the bottom end out of it" because the bottom end was "not used to that much power". What a focking idiot...

I installed the Summit cam, lifters and timing chain, and went from a 16.1 in the 1/4 to a 15.3. A GREAT under $100 mod. I sold the car w/200,000 miles to a friend. They sold the car w/ 230,000 mi to their friend, and it FINALLY blew a head gasket at 245,000 mi. That is 65,000 mi of great service. Anyway, I doubt it was the cam that caused the gasket to blow, since the engine had been SEVERELY over heated MANY times (by me).

Do the cam swap. I can assure you that you will be glad you did.

 

If I were you I would change my valve springs, and of coarse my lifters. Your springs have most likely loosened up a bit over the years and miles. Adding a cam with more duration/lift should require stronger springs than stock (when new). Im sure you will still get good results from your swap if you do not change the springs, but It would be a good idea.

oh yeah, while youre in there you may want to toss in a 350 j/k

Someone was bound to say it sooner or later. It might as well be a 305 guy.

-peace

 

It wont hurt anything. Run down to AutoZone and get a Melling MTC-1 kit $130. I love this cam! I put it in the 305 from the bird then poped the engine in my 4x4 and wow what a big difference. If that LG4 in you vett is as funkey as the one from an 82 FB it will love the MTC-1. Funkey compression, crappy heads, ect will give you fits tunning in high altitude so stick with a cam 118@.50 or below with the 305, below 115 is better.
SSC

 

Uhhh, do you mean "218 @ .050", or "115 lobe center"? The LG4 cam has around 190 duration at .050".

I don't have any trouble tuning with 216/228 duration @ .050", with 110 lobe centers. No trouble code set to date, either.

 

I swapped in a Summit cam at 127,000 or so. The car runs strong.

JamesC

 

My next question then. Which Summit cam should I use? I'm looking at the 272/282 cam here :

http://store.summitracing.com/partde...2116&part=6372

Looks like 2000-4500 is the range and it looks streetable. Just want to get some opinions so I don't do anything silly.

Matt

 

Thats probably not bad, but i would think you'd want something designed for more off idle torque... isnt 2000 a little late in the rpm band unless you have a stall convertor? (question, not sarcasm )

Those old 305's could have used a little extra torque down low in the rpms.

 

I went with Summit SUM-K1102 in my LG4 5-speed. I don't know if it's the best choice (though several articles/books suggested this range), but I'm quite happy with the results. The cam is in conjunction with an L69 dual snorkel, an Edelbrock intake (EDL-3701) and an L69 exhaust from manifolds back.

JamesC

 

118@ .50 or 115@.50. That's odd back when I wanted to keep the car legit (lived in your neck of the woods) I had greif with a larger cam 224/224@.50. It set about 10 different codes off. I moved ripped all the cc stuff out and replaced it and still it would run a oddly and pulled very low vac about 10in at idle out of gear. When I put the engine in the 4x4 I replaced the cam with an MTC-1 208/214@.50 and I gained 5in of vac at idle. Funny thing is I replaced a 4.3 with the 305 and it has a tbi sitting on top and still no codes 2 1/2 months later. So I dunnu maybee you have the magic touch. What kind of vac are you pulling with that setup? I could max it out at 12in but it would run a little funny.
SSC

 

Yea that seems like a good cam and you cant beat the price although I dident read if it came with lifters or not still $60 is a great price.
SSC

 

it depends on what the engine is like....my 305 TPI has 130K on it and it smokes like a mo fo and how less power the the new 305 sitting in the black camaro.....But my borther has a lumina with 130 on the clock and regular oil changes and it runs as good as new, so does out G20 van with a 350 in it....etc etc........If the engine is is good condition do it....if not hold off....look at the top of the heads, hopefully they are clean....mine are not....I hate ppl who don't change there oil.......what is so damned hard about it?!