Stroker question

**grandkodiak** · 06-27-2007, 10:02 PM

I have heads/cam/headers done right now, and Ive been thinking about a 383 stroker kit. I might have a bent rod since it just got flooded out, but i'm thinkin positive and assuming that this is just an excuse now to have more shit done.

my question is, i went with shortened rods and the impala gasket (thinner) and i was told the compression is now at about 11.2:1 with the gasket/head combo. now, if i get a 383 kit, can i lower that compression, if so what do i need to specify or look for in the kit, or how can i calculate what it will be? i dont like it being that high as it is, but id like to eventually turbo/super so id like to bring that compression down, to at least stock if not lower...

im guessing it comes down to piston choice? sorry, there are some gaps in my engine knowledge

**5.0THIS** · 06-27-2007, 11:01 PM

What do you mean you went with shortened rods? Pushrods, as in valvetrain? That has no bearing on compression ratio, and the impala gaskets wont make that big of a difference over the stock 10.5 comp. ratio.

The short answer to your question is that you need a dished piston to lower the compression ratio, or bigger chamber aftermarket heads.

**grandkodiak** · 06-27-2007, 11:05 PM

pushrods... i was told to get 7.150" rods, and the gasket was .029" thick... what would you need to know about the heads to know the compression with that data? they are loydes LE2's think they were 205cc

**5.0THIS** · 06-27-2007, 11:17 PM

Originally Posted by grandkodiak

pushrods... i was told to get 7.150" rods, and the gasket was .029" thick... what would you need to know about the heads to know the compression with that data? they are loydes LE2's think they were 205cc

Pushrods are just about valvetrain geometry... I'm surprised you needed new ones, although you may not have.

Your combustion chambers arent 205cc... that is your intake runners. Your combustion chambers stock are 54cc, but who knows if Lloyd messed with them. To know your compression ratio for sure, you need to know combustion chamber CCs, gasket compressed thickness volume, how far your pistons are below deck, piston valve relief volume. You're probbaly right around 11:1. I wouldnt worry about it until you actually are going to build the motor.

**jasonisdn** · 06-28-2007, 03:09 AM

Originally Posted by grandkodiak

pushrods... i was told to get 7.150" rods, and the gasket was .029" thick... what would you need to know about the heads to know the compression with that data? they are loydes LE2's think they were 205cc

measure measure measure.
never put pushrods in a motor without checking for the correct length. they make a tool to check the needed length. you can use the push rods you have to see if its to far to either end of the valve stem.

as far as your compression. if you are close to 11.3 you are fine, alot of folks run way more than that. compression helps make power on a NA and a nitrous setup, you need lower compression when you turbocharge or supercharge a motor.

**grandkodiak** · 06-28-2007, 06:20 AM

well i just got back from the mechanic, insurance company is sending out the adjuster. i swear if they total my car for this shit :'(

I did so much work to the car and i have all the interior parts on order, had so much planned and if they total it now..............

mech said the adjusters gunna see the water in the back seat and flip... theres only a quarter inch or so but that wasnt even really bad i didnt think... but there is shit on the filter so there is a good chance water got in, guess ill know in a few hours.

my decision is now, that since they are likely to total it, since they dont take in account all the new parts i just put in on it that probably isnt damaged.. they are probably going to total and cut me a check for the value which wont be much (96 with 64k miles) but i can apparently buy back the car if its totalled (they issue me a value check minus some fee like 20-25%?) and take repair responsiblity on myself, which i think would be enough, everything about the car is perfect otherwise... but then the cars considered totalled on my insurance and its on the carfax forever after that... what do i do now... ugggggggggggggggg

**BlackLT1Z28** · 06-28-2007, 09:18 AM

Just take the car with the salvaged title. And you'll be surprised what you'll get for the car. I totalled my first Z. It was a 94 with 96K miles and I got $5700 after deductible. With your's being several years newer and less miles, I think you'll get more than you are expecting. But every insurance company is different. Good luck man.

**grandkodiak** · 06-28-2007, 11:16 AM

Just shopping around lookin at stuff...

why is this kit only $700

http://cgi.ebay.com/ebaymotors/SB-CH...spagenameZWDVW

where the lunati kit on some sites starts at $3000...?

**jasonisdn** · 06-28-2007, 11:29 AM

cheap parts that can't handle much stress.

**grandkodiak** · 06-28-2007, 12:51 PM

is it atleast as strong as stock, like is it least some improvement?

**BlackLT1Z28** · 06-28-2007, 05:58 PM

I wouldn't even think about putting e-bay parts in my engine. If I'm going to do it, I would do it right the first time.

**jasonisdn** · 06-28-2007, 06:35 PM

Originally Posted by grandkodiak

is it atleast as strong as stock, like is it least some improvement?

the factory crank has held more than the eagles cast cranks have. stick with what you have been looking at. quality over price, do it right the first time and have a motor that you can enjoy instead of having to repair.

**grandkodiak** · 06-29-2007, 07:16 AM

Anyone makes moderate kits near $1200-1500? I cant do any more then that on my own right now...

still havent even heard from the insurance company yet though

**jasonisdn** · 06-29-2007, 07:46 AM

Originally Posted by grandkodiak

Anyone makes moderate kits near $1200-1500? I cant do any more then that on my own right now...

still havent even heard from the insurance company yet though

go google compstar. made by callies over seas of course. they can hold more than eagles stuff but not as expensive as the top shelf items. also check dickey scroggins (i might have spelled it wrong) his prices are hard to beat.

**BlackLT1Z28** · 06-29-2007, 09:05 AM

Originally Posted by grandkodiak

Anyone makes moderate kits near $1200-1500? I cant do any more then that on my own right now...

still havent even heard from the insurance company yet though

I don't think you'll find any forged stroker bottom ends for that with a reputable name behind them brand new. Lunati's start at $2500 or so I think.

**grandkodiak** · 06-29-2007, 10:06 AM

Problem is if its more then 60% of the value of the car (book value) its an auto total, at which point I will only GET book value. They refused to account the work i've put into it, so unless i can repair it cheap, I stand to loose alot of money AND the car.

**grandkodiak** · 07-06-2007, 08:11 AM

Alright I found out for sure, the head size is 56cc.

Now with a 383 kit, what compression would I be looking at? Or do I still need more info for a guesstimate.

**jasonisdn** · 07-06-2007, 09:09 AM

now the other factors , how deep in the hole will be piston be or a zero deck height. then comes gasket thickness,head gasket bore size, piston + or - cc volume. cam timing plays a role in cyl pressure. i have a program that will get you ball park numbers, if you want it

**grandkodiak** · 07-06-2007, 09:47 AM

i have a program i just dont know what data to enter...

Heres the data i have to enter:

bore 4"
stroke 3.480
cyc volume 716.62cc
comb volume 70.26
total vol 349.8ci
piston - dome, dish and/or reliefs
head chamber volume 56cc
head gasket bore 4" (guessing?)
head gasket thickness .028
head gasket total volume 5.77cc
swept cylinder vol 716.62cc

i'm missing the following data:

piston down bore at tdc in inches
volume above piston in cc

what id like to after that is change whatever i need to to represent a 383 kit installed to see how much higher it will get

**jasonisdn** · 07-06-2007, 11:58 AM

with a bore of 4.0
stroke of 3.480
chamber 56cc
gasket thickness of .028
i did gasket bore of .010 over 4
if its a factory block and factory piston lets just say .010 in the hole and a -5cc piston (just guesses remember that) 11.4 static with out cam timing i can't give you the dynamic. thats just a ball park figure remember that.