lavoy

iTrader: (2)

hey all , little back ground on the car first, its a 71 datsun 240z , i first had a stock ls1 in the car with a 6 speed and a single 72 mm turbo. the car made 500 whp and ran low 10s , i then swapped in a ls6 and a 2004r and went for the stock ls6 and stock bottom ls6 record in a street car on pump gas, as of now i believe i am the fastest in a completely bone stock ls6 and second in the stock bottom ls6 records with a 9.78, perhaps the stock bottom ls6 record has shifted around and im no longer second but i have yet to find any one with a 100% stock ls6 faster then 9.78. any way i recently purchased a 5.3 to do a 5.3 turbo build and later found out its a 4.8. so rather then be all upset about it i decided to go for the stock bottom 4.8 record, not 100% sure what it is but im sure some on here or over at the truck forum does. plans are as follows leave the bottom stock , use a zo6 cam and lifters, a worked over set of 862 heads and ls9 gaskets with arp studs. a 74 mm precision turbo and run pump gas with some meth. i will be reusing my trustly dusty ls1 intake and other random sensors and peripherals from the ls6.also and most importantly i will be getting tuned by steve from tunedbyfrost so the best possible tune will be on the car. so far i have torn down the motor and cleaned it up, ordered parts and gaskets along with the new turbo. today i picked up a 2 bar gm map sensor and hope to have more parts by end of the week or early next week. here are a few photos for now and i will post updates as the build progresses.

map sensor


motor when i got it home.


motor torn down.


and a random pic of the car in question


stay tuned for updates.

Spoolin_Notch

iTrader: (8)

Subscribed! I'm a sucker for a clean Z car. always wanted to do a 510 with a ecotec.

lavoy

iTrader: (2)

thanks for looking in

lavoy

iTrader: (2)

progress update. today i took the rods and pistons out to gap the top ring and man was i shocked, this motor looks like crap!!! the rings are all sludged up and stuck and there is light rust in the cylinder bores at random spots where water must have touched. regardless i spent 6 hours cleaning every piston till it sparkled and each ring and put it all back together reusing the stock bearings and all. i used some light sand paper to remove the rust as well. the new turbo came today so i am just waiting on the heads and few odds and ends before i can finish it up. i also have concern for the 4.8 rods when i put them next to my ls6 rods they clearly look weaker, so this makes me wonder how they will hold up.

NemeSS

iTrader: (127)

Im using a 09 4.8 in my build. But iits in immaculate shape.
And has the beefier ls2/ls3 type rods. 100% gm internals. I didnt tinker with shortblock.
But going with upgraded heads,studs,ls9 head gaskets.
Dont take this the wrong way, but it doesnt count if you tamper with the bottom end. If youre going for some kind of record. It should have an asterik*. If you can accomplish your goal.
Thats why i left my internals alone. Stock oil pump,lifters,rods,chain,cam,pistons,rings and ring gaps,etc.
But im sure it will fly in that light z

BMF_Racing

iTrader: (6)

looking good, good luck with the build. How much power are you hoping for?

Daz

iTrader: (18)

I'm doing the same build for my 74' 260z ! My bottom end is stock with Arp rod bolts, 2004 LS6 cam/springs, 241's, TBSS intake, F-body oil pan. I'll be going with a 76mm and a t56 tranny !

What did you do for a rear end and axles ?

lavoy

iTrader: (2)

actually taking apart the internals to inspect them or clean them up if they sat for years and glued them selves fast like mine did doesnt negate going for a stock bottom record, stock bottom is defined as having all the correct parts as it did when it was manufactured they dont have to be the actual original parts, you can actually replace everything with new oem parts and still qualify for the title stock bottom end as long as you used 100% oem parts that are the same part numbers as the originals. the only thing i am altering is the top ring gap so that will have a asterisk beside it if i do well, other then that i reused everything from the junk yard i just de sludged it. anything to do with the valve train and heads is not part of the bottom end so that can all be modified, you may use after market cams and lifters and push rods ect. but i decided to stick with all oem stuff from gm so im using my ls6 as a doner for those parts.

today i got more work done, i was able to swap over every thing from the ls6 valve train along with the sensors, i also swapped over both timing gears and chain and to my surprise even the oil pumps are the same part number as the 4.8 so i swapped the ls6 one over as well since it has lower miles. the 4.8 does not have a provision for the timing chain dampener so i wasnt able to swap that over. now im just waiting on the heads and gaskets and i can button it up.

to answer the other question about the rear end and axles i have used many set ups including the best parts from modern motor sports and drive shaft shop but something always broke so i ended up converting to a ford 8.8/9 inch hybrid axle and havnt broke anything since.

lavoy

iTrader: (2)

thats a tough one, i am wishing for as close to 700 whp as i can get. the car went 9.7s with the stock ls6 and around 600 hp. so should really fly if i can gain 100 more hp.

NemeSS

iTrader: (127)

I see,
Im gonna leave mine alone. As much as i want to put some clevites,arp rod bolts in there.
I want to see how it will hold up as it rolled off the assembly line.
But i can understand if the one you got needs reconditioning.
Dam, my car is nowhere as light as your z.
Goin in 4th gen
Good luck

99VetteFRC

You guys should check out this aticle.

http://www.hotrod.com/techarticles/h...g_bang_theory/

philofab

Nice car, any idea on weight?

lavoy

iTrader: (2)

as you already know your 4.8 is leaps and bounds better then my gen for strength, you will be fine.

as for my weight it was around 2650 with me in it and the ls6 now i think it will be about 80ibs heavier from the cast iron block

philofab

Wow, that's a light car.

lavoy

iTrader: (2)

more updates , i got the last of the parts swapped over from the ls6 including the timing chain and gears and all the sensors, now just waiting on gaskets and heads to get here and ill button it up.

lavoy

iTrader: (2)

video time
http://www.youtube.com/watch?v=onuPy...layer_embedded

whittmotorsports

Thats awesome.. I love junkyard builds.. These LS motors sure are tough from the factory

sq_creations

iTrader: (5)

Awesome to see another turbo ls swaped z. Good luck with your goals.

BLK95-Z

iTrader: (2)

What year did they start putting the better rods in the 4.8?


I love reading about junkyard motors making good power.

Nice build

lavoy

iTrader: (2)

thanks guys , got rained out this weekend so have to wait a week to see how it runs.