LT1 Cam Selection?

[JoeliusZ28]

Joel, isn't it true that the amount of overlap will roughly determine the vacuum (more overlap = less vacuum [been a while since I dialed a grind in])? I know spring rate and other factors make for the end result, but on a grind level?

yes

Well, I understand the LT4 hot cam kit is everything that's necessary -- I guess my only question left is if there is anything comparable that doesn't require tons of supporting mods (read: is cheap and simple). Everything that I've googled makes the LT4 hot cam kit sound like the best option if I don't want to do head work.

I did skim through the first part of the cam sticky -- I'm kind of understanding the cam specs, but I think my biggest question is where is the line that a cam is "so big" that it requires head work and/or other supporting mods. For example, if I go with the LT4 hot cam kit, it sounds like I have everything I'd need. If I went with a different cam, will I need to purchase anything [supporting mods wise] else like larger injectors, fuel pump, etc?

There is no "line" that heads are required, just a subjective line that is stupid to cross without heads. The reason being is that you are relocating your powerband to the north... and the more power you put up there the more headflow you need to have. (IE a cam that peaks at 7k isnt a good idea on heads that start choking power at 5K). That being said people run GM847s (larger than anything you will want to run) with pretty good results.

Im still running stock injectors and fuel pump - however I havent gotten my tune dialed in yet so im not sure if ill need bigger injectors or not yet. Injectors arent that big of a deal really, theyre cheap and easy to change. fuel pump can be.

Im a big fan of the Comp 503 cam...it is suppose to be a great streetable cam that gives you great power...I actually was going to install one on mine but plans changed and i sold it. I know you said you dont want to deal with a heads package but you may consider a LE heads cam package...they are very reasonably priced.

The 503 is what I had planned on getting for over two years before Advanced Induction came around and finally started covering some of the middle ground. Its a very proven cam with stock heads, will make a little more power than a hotcam but they are comparable.

Brian if $600 is your limit, the LT4 kit is pretty much your only option.

I was reffering to the LT4 cam/heads/intake package. That is what I believe costs a shit load and doesn't do much for power.

lol ok my bad then.

My guess is that anything bigger than the LT4 HC (or similar) will require head work to get the most out of the cam.

I know too many people that install that "monster" cam to get the lope, and end up slower that what they were before.

Contrary to what most people think (because of the LS1)... LT1 heads flow pretty good. Good enough to support pretty sizeable cams and get solid gains with them. Overcamming is not so much of a problem on LT1s as is overcamming and then failing to tune the car correctly. Those are the people that completely throw their money away.

[Will]

I don't think you can even get the GMPP LT4 kit anymore. Everywhere I've seen a LT4 kit for sale says you need to find your own intake.

[JoeliusZ28]

LT4 castings are no longer in production to my knowledge.. theyre worth some nice pocket change.

[81DaytonaPaceCar]

Contrary to what most people think (because of the LS1)... LT1 heads flow pretty good. Good enough to support pretty sizeable cams and get solid gains with them. Overcamming is not so much of a problem on LT1s as is overcamming and then failing to tune the car correctly. Those are the people that completely throw their money away.

What's the combustion chamber size on a LT1?

And what's the stock compression on a LT1?

[meissen]

Sounds like the LT4 hot cam kit is what I want, then.

[JoeliusZ28]

it varied year to year from 10.1:1 - 10.5:1 and the combustion chambers are ~54cc likewise.

Sounds like the LT4 hot cam kit is what I want, then.

How concerned are you about power? LT4 is a great cam for good sound and decent power, but there are definitely better performing grinds out there.

For what its worth i figured id throw the details of my build out again, and in my opinion seems mild but thats subjective

AI 226/234 .540/.575 @ 110 LSA
~11.4:1 Compression (stock heads milled .020 w/ Impala gaskets)

Also brian while I am thinking about it... MAKE SURE you upgrade to the GM "White" oil pump spring while you have the oil pan off. VERY worth your time to do when its easy... and only a $3 part. (this was the hardest part of doing my build w/engine in the car).

[meissen]

How concerned are you about power? LT4 is a great cam for good sound and decent power, but there are definitely better performing grinds out there.

It's two fold, really. I'd definitely like "the most bang for the buck" that wouldn't be too expensive. I understand there's better performing out there, but would it fall into my price range? All said and done, I'd really like to be under $750 for the cam swap.

I guess it's really three-fold -- the question about power is really relative to me. This entire swap to a v8 is more than doubling the horsepower of Red Alert. So, in a relative world... since I've only driven an LT1 vehicle once, any cam upgrade is a plus... but I want to make sure I'm getting my money's worth... I wouldn't want to spend $550 on the LT4 Hot Cam kit and gain 50hp if I could spend $600 on a different cam and parts that the kit supplies with it and gain 75.

How much horsies are we talking about with an LT4 hot cam, anyway? At this point I'm just camming it because I'm there and it's a good time to do it, and I want something that just sounds good and is a good choice for a cam... I associate 'good choice' with "most bang for the buck" but as far as horsepower is concerned, I hadn't even thought about what kind of HP gains I'd get.

For what its worth i figured id throw the details of my build out again, and in my opinion seems mild but thats subjective

AI 226/234 .540/.575 @ 110 LSA
~11.4:1 Compression (stock heads milled .020 w/ Impala gaskets)

If you don't mind me asking, how much [round up or down $100-$200... I don't want to intrude and don't need a specific $$$ to the cent amount] did it cost for that, including the milled heads? Really, if it's over $1000, that's well enough out of my bracket for right now.

Also brian while I am thinking about it... MAKE SURE you upgrade to the GM "White" oil pump spring while you have the oil pan off. VERY worth your time to do when its easy... and only a $3 part. (this was the hardest part of doing my build w/engine in the car).

Thanks for the tip -- I didn't even know I'd be dropping the oil pan. Oh god do I have a lot of reading to do.

[Lucky SOB]

ya brian. gotta drop the oil pan to get the timing cover off.

[JoeliusZ28]

well not only that but im not sure if the vette oil pan is the same.

I cant remember what the head milling was, but it was $100 bucks tops....nowhere near 1000 lol. And just in case you didnt know, milling != porting. I had the milling, some very mild porting, and valvejob on the intake side done for $400 total from dave at engine craft in waterford.

here are some part numbers for ya:

-10128485 replacement timing chain
-3848911 white spring

[MP81]

I think they're different.

[MunsterZ28]

ya brian. gotta drop the oil pan to get the timing cover off.

this isnt true, me and my dad did my lt4 hot cam kit and never pulled the oil pan off??? got the timing cover off and everything 8-O

[JoeliusZ28]

its possible, just isnt easy.

[MunsterZ28]

its possible, just isnt easy.

lol i dont remember it being a simple task but my pops didnt wanna go threw taking the pan off

[SLPSS]

ride

if I see you at a-u sat I will take you for a ride in a 4000# rag top.Then you can fell how a lt4 hot cam, 1.6 rockers, jett hot long tube headers, no cats, and a few other things to make it go fast, bmr sub frame conc., spohn tunnel brace, dynoed by Sean picked up over 1 second at strip and spinning tires, street tires with a 2.1 60 ft like I said a 4000# car

[meissen]

You got it, Pete!