erikthegoalie

iTrader: (29)

Tech guys, this one is for you...


I have been reading a **** load of posts and it seems as if though things like DCR and QUENCH and SCR (spelling, sorry if I got the acronyms incorrect) are rather important things to consider when selecting heads and cam packages..actually they are VERY important to getting the most out of your set up!

HOWEVER, for the average guy who just wants to hook his ride up, give it some "*****" and have a good time, does it REALLLYYYYY matter how nitty gritty you get with these three measurements?

DO NOT get me wrong, I do NOT want to half *** anything. If it means measuring my quench and all I will, it just seems that those are three variables that make for an EXTREMELY difficult time of choosing just the right set up...

I mean as if PRICE wasn't enough of a factor-now I have three more very difficult elemsnts to deal with....

I guess what I am asking is, how much emphasis should the "average" F body/LSx enthusiast put into these elements when selecting a head/cam combo?

Thank you very much
Erik

Beast96Z

iTrader: (21)

The thing is, is that measuring those parameters can be done with simple calculators and the only thing that will cost you any extra is the head gaskets. Your gunna buy heads/cam/gaskets anyway, so why not get them at the correct specs?

Here, I did it for you: 224 XE-R cam on a 112+2, .040"/3.910 bore cometic head gaskets, and 64cc heads. Equates to 11:0 SCR, 8.6 DCR, and .033" quench. Could run 62cc heads for a bit more umph if you have good 93 octane gas and a good tuner.

erikthegoalie

iTrader: (29)

I agree. Ok, so onto my next BROAD question (I know), what tools should I purchase so I can make these correct measurements, OR what formulas should I find...
I realize that I could probably just ask a sponsor, but I have gotten some not so clear answers in the past, and I would like to do it on my own, or at least learn...

I appreciate it!

Erik

Beast96Z

iTrader: (21)

Edited my above post, read that 2nd paragraph.

erikthegoalie

iTrader: (29)

Hey man thanks a lot...
If you could, maybe determine those specs for my set up in the works...(only if you want to man I know youre probably busy haha)
MS3 113 LSA, PRC stage 2.5 5.3L heads, milled to a 59cc chamber, 3.910 bore/.040" cometics

My concern with this set up is that the compression will be a bit high for the 93 octane we have around here....and I DO NOT want to have to mill heads, fly cut pistons and buy $$ gaskets only to hurt my engine by detonation when I could run a set up that require little or no modification to get it to fit with comprable numbers...

You see?

Erik

Ryan02SS

iTrader: (3)

Send me a PM with your email and I can send you some DCR/SCR Microsoft Excel calculators. You punch in the info and it will compute it for you. Like was stated above it's easy to learn and is the proper way to go about making a complete setup.
Once you start plugging in cam specs and learning what will make power you might find yourself with a cam to better suit your goals.

383Z4ME

http://members.uia.net/pkelley2/DynamicCR.html

erikthegoalie

iTrader: (29)

great thanks!

Z O SICK

iTrader: (1)

Good link! Lots of info!

The Alchemist

iTrader: (19)

On this same topic, how much can you mill a set of 241 heads and run an 0.040" gasket with a TR224 112lsa cam?

The reason I ask is I need to pull a head and have a broken header bolt drilled out and the hole filled and retapped. While I have the head off, I'd like to replace the factory gaskets (0.056") with something tighter to get my DCA up and quench down.

Here's my problem. As my signature states, I have a set of JPR heads with 2.05" intake valves that I'm not certain how much was milled off them. It might have been just a cleanup minimal amount, or it could have been 0.030 - 0.040 off them. So my question is how tight of a gasket can I go with having the TR 224/224 112lsa cam without having issues of piston to valve clearance.

I plan to put clay on the #1 piston and bolt the head back on with no gasket and manually turn the motor over to see how much clearance I actually have. But does anyone have experience with the TR224 cam with respect to PtoV?

I plan on calling Thunder Racing and talking to them as well.

DONAIMIAN

iTrader: (18)

Once the heads are off the car, send them to a machine shop and have them CC the combustion chambers. That'll tell you the chamber volume and will let you know if you need/want to mill anymore.

J-Rod

see sticky at the top of the page for DCR/Quench/CR, etc... spreadsheet

The Alchemist

iTrader: (19)

Guys I understand what you are saying. I can CC the chambers myself, I have the access to the volumetric burrettes to do that, but my concern is PtoV clearance dropping the gasket thickness without knowing how much was milled off my heads.

I guess the only real way to make sure I won't have problems is to put clay on the piston and gently spin the motor over by hand and then pull the head and check to make sure I have the needed clearance.

DONAIMIAN

iTrader: (18)

lets say you CC your heads and you end up with 63cc chambers. Knowing that 1cc off an LSX head is about .006 you will know that ~.018 was taken off the head if it stared its life at 66cc.

The Alchemist

iTrader: (19)

Cool, thanks for the heads up. At this point, it just comes down to pulling the heads and taking measurements.

cantdrv65

iTrader: (3)

Id stay away from the cometics because of the sealing issues. Its not worth more than 5hp and it sucks to pull the heads again because of a leaky gasket....you'd be much better off to go with the stock GM MLS gaskets and forget about it. Im glad I did.....If you are one of those guys that likes to eek out every last hp and are willing to put up with possible issues, then go for the cometics. My car lays down 450rwhp with budget heads, small cam, stock MLS gaskets and stock Ls6 compression so im happy.

FDLS1

iTrader: (2)

OK, maybe this will help. I run 241's milled 0.030, 0.040 cometic gaskets, and a 226/230 cam without P/V clearance issues. BTW, I have no leaks either.

Nate_Taufer

iTrader: (1)

If you're worried about your head gaskets not sealing then either your heads or deck aren't true or you installed them incorrectly. You could always run the Titan SCE gaskets as they have a small gasket lip to seal the chamber and cost the same as the cometics.

Also if you like scraping gaskets off the block and heads everytime you pull it apart then go right ahead and run the stock MLS gaskets.

Nate

The Alchemist

iTrader: (19)

That's the kind of info I like to hear.

I'm not worried about the gaskets sealing. I've heard that prep is the key, use a little copper spray, and torque the heads properly and you should be okay.