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I am out of town for work but I get back tomorrow so I will take apart the most recent broken opti, then I will strip everything down and take some pictures of the timing cover, cam dowel, etc. I'll also double check the vacuum setup to make sure that its right.
Looking at shbox it looks like the dowel pin should be between like .620" and .685" -With this being a brand new motor that has done nothing but eat optis, I wonder if the cam dowel is not right like you guys are suggesting. I'll measure and send that along with the pics tomorrow when I get home.
Lol I just sent my dad a pic of this car off Google yesterday to show what the blackbirds stripes would look like on his car... anyway Non vented, vented, delco,msd,locktite the rotor screws.. .. all failed for me. I did the 24x swap, here's my problem with that tho, why should you have to pay 2k+ for your car to run how it should(you won't gain any power just reliability)..
So my car ran great after the 24x but I was already at 600hp 13.1 lt4 on e85 and still wanted to grow.. well with the ls2 I'm making 700+ wheel which is what I was lookin for. That said there's nothing wring with the lt1/4 with 24x swap but don't expect to pick up any power from it.. I say put that 2k toward a ls motor. ... here's my old lt4 with 24x for sale in a buddy's car. I can't believe it ain't sold yet.. http://madison.craigslist.org/cto/4657895320.html
^^^ btw my motor only had 4k miles when I sold it to him under a year ago,, 383 fully built, 13.5:1, e85,24x, he's basically giving it away considering what he gave me for the motor/trans. . And the fact that he personally built this car and he's a certified mechanic and has 3+ high HP cars of his own he built. Garunteed this car is sound coming from him
You guys really think its possible for engine vacuum to flex the cap? I'd love to see pictures of OP's destruction.
So much engine vacuum it sucked the injection molded cap and deflected enough to contact the rotor, but didn't suck in or collapse the cheesey soft rubber hose running to the opti.
^^^ btw my motor only had 4k miles when I sold it to him under a year ago,, 383 fully built, 13.5:1, e85,24x, he's basically giving it away considering what he gave me for the motor/trans. . And the fact that he personally built this car and he's a certified mechanic and has 3+ high HP cars of his own he built. Garunteed this car is sound coming from him
Seems like a good deal. Just hard to sell 4th gens.... it would cost more than that easily to build any LT1/4... then it narrows things down because "no egr junk".... Lots of places in the country have to have emissions testing to get registered.
I just moved from wi to co and there were no emissions either place.. I have had my car worked on here in co at h&d motorsports. The owners are father n son( father is a federal Marshall and son is a sheriff here) they have a contract with the county so when I go to there shop there's always cop cars there... n they love working on my car and riding in it to. Some cops are cool with modified cars I guess!!! The son todd has a 57 Chevy big block blower alcohol car. The dad Jim has a 69 camaro and plans to brake land speed record in his class at Bonneville at 250mph...
Anyway yea I say if you can afford the little extra for a ls motor and have something else to drive in the meantime I'd look for a ls.. you can sell the lt to pay for the ls. Or keep the lt just tackle that opti problem.. plenty of ppl have. ..
I just wouldn't put 2k in a ignition system when you can buy a motor swap(ls) with the same ignition for not much more
Seems like a good deal. Just hard to sell 4th gens.... it would cost more than that easily to build any LT1/4... then it narrows things down because "no egr junk".... Lots of places in the country have to have emissions testing to get registered.
Dam I just realized it in co too.. where at? Any chance ur in southern co? Seems like the car seen is dead down here.. I need my car tuned after moving here and I can't find a place to tune my ls2. .. only Dyno near me is stett performance in farmington nm which is 1 hour but he don't has software fir ls.
Where abouts in Colorado are you? Im near the Royal Gorge Bridge.. Canon City
Durango. Trying to get the car seen up and running down here... one other guy in town here has a ss trailblazer and is building a 67 boosted ls Chevelle. . Other than me and him it's all jeep,diesels, and yuppies with porches, ciphers and stuff... although the subaru/tuner crowd seems pretty thick here... I moved here only to find out there is no e85 for 2 hours away.. now I need a tune
certainly confirm dowel pin length as with the 383 whatever cam is in it the pin may have not been cut to right length
BUT!!!... first confirm you have a correctly installed vac harness. One without the check valves (reducers) installed will allow full engine vacuum...which is way to much
and FWIW back when my 96 was still under warranty and Mr Goodwrench was replacing a WP & Opti he reversed the check valves causing no venting....SEVERAL Optis later that the dealer put in were killed in 500-800 mi each. All due to condensation building up inside the Opti (not wp coolant leak) the crap would almost just pour out.
I happened to notice the reversed check valve myself...flipped it over...still have same Opti now. So point is a non venting system will quickly kill Optis.
Confirm Opti vent system works and the cam dowel pin is not to long
Durango. Trying to get the car seen up and running down here... one other guy in town here has a ss trailblazer and is building a 67 boosted ls Chevelle. . Other than me and him it's all jeep,diesels, and yuppies with porches, ciphers and stuff... although the subaru/tuner crowd seems pretty thick here... I moved here only to find out there is no e85 for 2 hours away.. now I need a tune
Had to go clear up to north Denver to get my 2002 Z06 tuned. I heard there were a couple places in Colorado Springs....
Carnage Pics! Let me know what you guys think. Also, the rotor screws were kind of loose, the rotor had some play in it. But I think this may have been caused by the internal collision.
Also, now you will see what I meant about there only being one vent line. the opti is vented but the cap is not. And this vent was hooked up to the DS intake manifold. There is a check valve on this line and it is installed with the blue side to the opti, white side to the intake manifold.
So I just pulled the vac line from the intake manifold and tried sucking on it. It was very difficult. I fliped the restrictor around and it was very easy. So i think i have that part installed correctly. Also, looking at the marks in the pin drive area of the failed opti, it looks like marks from the dowel go about 75% of the way down into the groove which leads me to believe that the dowel is the correct length. I hate to pull it apart just to confirm that
very happy i saw this thread...the opti on my car only has one vent as well and it isnt hooked up to anyvent tubes and also have the msd 2al put on by the previous owner. after sitting for a couple years i went to start it the other day and it would just crank and back fire. thought the timing was off, but now i think i know the culprite. so i am going to get the msd cap/rotor kit and a delco ignition coil. but before i buy anything i will pull the opti to check it out and make sure that is the problem. thanks for all the good info guys!
10-30-2014, 09:44 AM
You guys are good! I just put a vacuum pump on mine and blocked off the intake side. You can't pull vacuum on it! Is my opti broken? Should I go ls1? 
