So what happened to your 408 that you built and it only lasted 500 miles. Did it come apart or starting knocking, smoking, break the block what? was the 408 a boosted motor or N/A. what parts were used to build the motor?

 

thanks guys , great info Skeet

smokeshow , what I meant was I dont want to lose this engine too , I want to take it nice and easy for 1500-2000 miles
whats the optimum "safe" A/F ratio and timing

my SCR is 7.3~:1 my DCR is 9.5:1~

injectors are 36lbs , I asked a tunner here and he said this will get you to 550flywheel hp no problems

and I have some 72lbs@43.5psi that are ready to go dont know if the stock pump can handel them , I think with a low IDC I wont have any pressure drop below 6500rpms


ShawnSS
what happend , I dont know
broke in the motor with some 5-30 full-synt oil used and oill additve that I dont know for sure if it has the ZDDP or not but was recomended by many , bearing clearinces were on the dot over .002 on 1,2,4,5 and .0027 on # 3 main
the rod bearings were between .0018-.0021 seams to be in spec

oil pressure never droped under 42psi since day one

engine drove great , no weard sounds what so ever changed the oil after first heat cycle with filter , changed just after 200 miles , then keept the same oil from 200-530miles

just when the odo hit 800km arround 530 miles I couldent keep my foot and steped on it ( tune was not spot on but timing was droped to under 25* with 91, first was great , second had some sort of light shake , shifted to 3rd and seamed slow , and just arroun 110mph the motor just died , stoped cranked it , didnt work for 4 times
stoped for 1/2 houre , started the motor , no sounds , oil pressure was 10-15psi max and I didnt step on it just turend it off imidetly , called my cusin to tow it .
stoped for 3 days no cranking , started the engine with 20+ years experince mechanic , the engine knocked , it was the bearings he said

thought it was a rod only , but it was more

4 front rods spun , #1 main spun

components are

callies compstar 4" crank , compstar I beams , wiesco pistons
bearings are king for main and rods

oil pump is L92/L99 dod high valume & pressure pump
rollmaster double roller timing chain with spacers
the motor didnt have any oil leaks

the shop who poped up the motor couldent put their finger on the problem and the said the ARP mains were not stable like the OEMs , and the were not tightend enough , I did the motor assembly , this isnt my first motor , I always double torque 3 times at least

what went wrong I really dont know!!

 

What happened is the DOD oil pump you used drained the oil pan dry (sustained WOT runs) before it could drain back to the pan.

 

Good possibility, puking rod, main bearings usually comes from 1 having them sized wrong or 2 oiling issues in many cases. I will say it again, I have seen more high volume pumps take out engines then the factory oem pump. The oem pump can pump 60lbs of oil pressure no problem, you only need ruffly 10 lbs for every 1000 rpm to be safe..

 

Yall read what Mangled03gmc said typed again, this is 100% true.

 

that was my first thought , and thats why I posted the bigger oil pan thread

but every one I told about the pump sucking the pan dry laughed at me

 

Build two more engines, use DOD oil pump on eng #1, use non dod pump on eng #2. Then do two long wide open throttle runs on both engines and post the results.

Seriously, its the oil pump you used. Id never believe this either had I not killed an engine the exact same way. 10psi per 1000 RPM is right where the pressure needs to be, there is no need to peg the oil gauge at part throttle...max possible oil pressure is not gaining anything.

 

Stock pumps can suck a pan dry if it is slightly low on oil... That HF bs came when the old push rod pumps needed to flow more. Ls pumps work dif. No reason for a bigger oil pan and big huge pump.. Just my op.

 

I got the 10296 , sticking with it from now on

but I also will swap cams on my friends L99 camaro , will delete the DOD but not the VVT , which pump to go with?

 

I always run a high volume pump in any engine that gets used harder then stock, just fill it a bit past the full mark and the operating level will be the same as with a stock pump. As far as brake in you got 500 miles to seat your rings, if you idle around the first 500 miles it will use use oil, give the bearings a few heat cycles and 100 miles then lay the hammer down. As far as tuning, there's no such thing as a safe tune, running it rich just washs out rings and low timing just makes less power, set the af at 14.6 cruising and 12.5 wot, set timing according to setup.