Gen I and Gen II small block differences
My guess as to why people go to Gen II from I, is the similarity between them. Other than a few external block changes (timing area basically), they're pretty much the same damn motor. Many parts still interchange, or with a bit of work, are able to be used still on a Gen II.
If you really want to know the differences, I'd say hit up the Newbie FAQ and Wiki.
I have personally put about 170K miles on my two LT1 vehicles, and only once id I ever have a problem and it was just a worn out cap and rotor which just caused it too run poor in the rain and the cap and rotor are wear items on EVERY engine that has them.
The LT1 has much better heads than any factory GM ones, this is the single biggest advantage, then the reverse flow cooling and very flexible injection system combine to allow us to run some pretty step compression.
The iron head stock LT1 in my wagon cranked 200psi at 180K miles, is 10:1 static, runs on 87 octane wonderfully, the one in my Caprice with 100K on it and raised compression(11.2-3 milled heads and thin gasket) and custom cam cranked 230psi. Don't know of too many gen 1s that can handle that, 12:1 is not unheard of for a street LT1.
The ONLY drawback to the LT1 injection system is the pcm can not go past about 7000-7200, but we still manage to make some pretty serious HP below that, the times in my sig are with a 6150rpm shift point, so it is making substantial power without revving too high.
the one in my Caprice with 100K on it and raised compression(11.2-3 milled heads and thin gasket) and custom cam cranked 230psi. Don't know of too many gen 1s that can handle that, 12:1 is not unheard of for a street LT1.
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Sorry Dude, but many of the opti problems come from simple maintenance neglect. Like a new cap and rotor, and a new vent harness (on vented optis) I had 150K on my original opti. Only reason I replaced it was because I was tearing off the waterpump and figured it'd be nice to have a spare. Friend of mine has 250K on an original optispark. Sure it could use a new cap/rotor, but it's still running. IMO the opti gets a lot of it's bad rep from the unvented versions.
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LT1s run 12:1 with premium and no detonation
Gen 1s can run 12:1, but good luck doing that with pump gas
Obviously not all are going to have a 100% survival rate. A lot of guys spinem over 6500rpm. Heck I recall Ellis going back to an Opti.
No the thing is these forums are filled with STUPID kids that just repeat everything they hear so when 1 in 10 optis goes bad they blow it out of proportion and neglect to mention it was 100K old.
None of the LT1 cars I have ever worked on have ever had a quality or design issue with the opti, I have a lot of friends with LT1s, hell I have a lot of friends that own multiple LT1 cars. A friend and his wife both daily drive modified Caprices, had tranny problems, axle problems, brakes, but never an opti.
I think people are also too quick to want too overev, my car runs what it does and has never seen above 6500 rpms even during a shift, the opti on it has 80K on the base and 12K on the MSD cap and rotor every bit of that with this heads and cam package.
I am speaking from actual experiance here, not some kid who read something once, not some kid who did something WRONG and blames the parts.
I had mentioned the reverse flow cooling already too, I just think that the credit for the compression capabilities needs to be shared with the injection system and the opti for that matter, it is much more accurate than the HEIs due too the shorter drive system with one less set of gears.
I also recognize the similarities between the motors, I have actually pointed out to folks that 2 piece rear main cranks can be used in this block, and I have many times told people who wanted to carb an LT1 that without the injection the LT1 is little more than a gen 1 with reduced head and intake selection. Like I said here the reason it makes power over factory gen 1s is simply better heads, otherwise they are very similar.
I have struck a better balance of research and experiance than most of you, some of you just slap all kinds of junk together without research, others get all caught up in the bad info presented my the majority of posters on forums, the guys that actually go fast for a reasonable amount of money strike a balance between research and experiance. Have too be able to sort through the 10 kids who just bought the car a week ago saying the opti is crap and realize the 3 guys who have had their cars for 5-10 years might know a bit more, that is why the SEARCH function is not the best source of info. You have to put the time in to know who is a stupid kid and who has the experiance and knowledge to backup their opinions.
I was one of the stupid kids at one point, I am just man enough to admit and learn from my mistakes and then identify who is posting good info and learn from them.
My 3rd gen Camaro, just stopped running one day without warning, after walking to work for 3 days until I could work on the car at weekend, it turned out to be the Ignition module (in the HEI).
Sara Lou
dh IIRC I think nissan used a very similiar unit to the optispark on one of their older engines. Its doom was placement. Somewhere near hot oil IIRC.


