my origional engine blew up so i got another 305 block out of a 1989 caprice that was tbi. i put my origional tpi cam in and swaped intakes. everything is the way it was with my origional engine, but it wont stop pinging under load.mods: this car is airfoil, exahst, and custom cold air induction. it has brand new injectors, timing is set at 6*, i've tryed the timming every where and the more retard the better the pinging gets but i loose power. this is the second engine i've put in this car and they were both tbi blocks, and they both ping the same. i am a audi tech at a porsche, audi dealership and me or the guys i work with can't figure it out. i've tryed a fuel filter, adjusting the tps, unplugging the vac. to the egr, top engine cleaner, checking for vac. leaks, your name it i've tryed it. anyone ever had the same problem, or suggestions? please help?

 

i may not be 100% correct but did u take out the knocke sensor form the original block and put it in the "new" one

 

i checked the part #'s and the knock sensors are the same

 

do you have the tpi heads on it or tbi heads? both were 305's right? i'm not to sure but if the LO3(TBI) has a lower compression, with the TPI(LB9) PROM i would think the timing is too aggressive for the comp ratio. just shooting ideas out. come on guys lets help him out.

 

yes the heads are the TBI heads. i got the origional TPI heads in my garage. after the origional engine went i had it rebuilt, put it back in, and it didn't ping, but i found out it was no good, the block was cracked. i think it's got to be something different between the TBI block, heads, pistons, ect. and the TPI. but i thought the engine internals were the same. so your saying the TBI heads are less comp. i really don't want to have to change the heads unless i have to. but i think your right that could be my problem. also i forgot, the guy i bought the car from said it had a prom in it, but i don' t really know for sure. does anyone know the differances between the TBI internals and the TPI internals?

 

the tbi and tpi block are essentially the same. the parts that go in them are slightly different. the heads on the tbi are swirlport. the are good for low end torque and fuel efficiency. but they suck. you cannot get too much power out them. tpi heads have 58cc chambers. tbi i am unsure of. the cam between the tbi and tpi is different. the tpi cam has more lift. the pistons i am also not sure of. the tpi LB9 has 9.5 : 1 comp ratio w/ 58cc heads. the tbi on the other hand (that came out of the caprice i am unsure of. since you have all the tpi stuff on the engine with the exception of the heads, i can't see much else besides what i previously wrote. the timing being to aggressive. check fuel pressure and make sure it's not dropping on you and leaning out.

 

thanks i'll check the fuel press. at work on monday. i think i am gonna be swaping heads soon.

 

my fuel press. is good. i think i'll have to swap heads. i have a 350 in my garage. it's a 1979 engine. can i put my TPI heads, intake, ect. on it and put it in? what kind of cam should i run, it's not a roller engine? can all my 305 parts swap over?