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-   -   difference in engines (https://www.thirdgen.org/forums/tech-general-engine/513137-difference-engines.html)

IROCmatt 02-23-2009 12:49 PM

difference in engines
 
whats the difference between these engines, my cars a LB9 v8 and the one ive bought to go in mine is either a LG4 v8 or a L69 v8, i take it its just the power differences

rockit 02-23-2009 12:52 PM

Re: difference in engines
 
uh, whats the condition of the lb9?

here's what's the same on all these engines, not worth it.

ill be more detailed, all are 5.0's, and thus are shunned for displacement inadequacy and short windedness.
depending on what year your lb9 is, the l69 might be the same engine with a different intake.

unless the lb9 you have is toasted, it's the most valuable of all three, but still, 350's aren't hard to find cheap anywhere on this planet, neither are 305/5.0's but the rule of thumb is build the biggest engine you can afford to build, and a 350's within spitting distance of the cost of a 305, does that make sense?

safemode 02-23-2009 12:59 PM

Re: difference in engines
 
L69 is the high output 5.0 maybe cam difference?

rockit 02-23-2009 01:03 PM

Re: difference in engines
 

Originally Posted by safemode (Post 4055210)
L69 is the high output 5.0 maybe cam difference?

l69 had a vette cam i beleive and okay heads, i had an 85 lb9 which was actually a tpi'd l69, and that engine had seen better days, but i got it to go 15.4's before i swapped it for the l98, i liked the lb9, it wasn't a thrill in a straight line, but it had a nice arrangement for the powercurve that made it predictable and a blast around the corners, the l98 just wants the rear end to go first wherever you are. needs to be stealth ramm'd.

IROCmatt 02-23-2009 01:33 PM

Re: difference in engines
 
basicaly my lb9 is tpi and engines beyond repair, the donor car ive bought has a lg4 or a l69 i cant tell which one, im just checking on this coz i want the new engine to run tpi

IROCmatt 02-23-2009 01:36 PM

Re: difference in engines
 
the car ive bought for parts has the fan bolted on the water pump, the car the engines going in is a tpi iroc early 86 so manifold bolts are the same

rockit 02-23-2009 01:37 PM

Re: difference in engines
 
what year is the donor car?

IROCmatt 02-23-2009 02:07 PM

Re: difference in engines
 
im pretty sure its a 83 but may be an 84 the reg certificate does not show it. and does not have age related plate, its got a fiber glass hood its blue with silver skirts has a fan on the water pump, but does say z28 on it and had a holley carb

IROCmatt 02-23-2009 02:33 PM

Re: difference in engines
 
ive got the engine number here does any one know how to tell which one it is from it?

five7kid 02-23-2009 02:47 PM

There's a sticky on the FAQ forum about the differences between 305's.

In summary, from '82-'86, all f-body 305's got the same heads. Cam, compression, and exhaust were the primary factors that affected power. L69 and LB9 had 9.5:1, as did LG4 in '85 & '86 - flat top w/valve relief pistons vs. dished pistons in the '82-'84 LG4.

If your "new" 305 is an '83 LG4, it has low 8.5 compression and a lame cam. If you have the car, look at the 8th character of the VIN - H = LG4, G = L69. If it's the L69, it will have (had) a dual snorkel air cleaner. The long block is basically the same as your LB9.

IROCmatt 02-23-2009 02:52 PM

Re: difference in engines
 
ideal yep its a lg4, so will this still be ok to just drop the tpi on to as my cars a tpi iroc


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