This is a little strange. I picked up a brand new 3.4 dohc v6 at a small engine dealer/rebuilder in middle Georgia, today. They had bought it from GM in a bulk inventory (Mostly 4.3, v6's) sale. It has a 12 month/12k mi. warranty. This is my fourth 3.4 dohc engine, but the first new one. When I got it home this evening, I noticed some tags on the engine that show the part number as 10192561. The tags, also, indicate that the engine has never been run and requires valve lash adjustments before running (intake .002/exhaust .026.) One tag says to "Use 100+ octane fuel, only; heavy-duty, off-road use, only." Another tag says "Not recommended for marine use."
Does anyone know what I've stumbled on to?

Also, I'm selling two of my used 3.4 dohc's. If anyone is interested. "One from a '93 Lumina, ~45K mi. and one from a '95 Cutlass, milage unknown. Both engines have good compression, oil pressure and run smooth.

Sorry- The intake valve lash is .022, not .002.
Please help me solve this mystery.
Rick

Never heard of valve lash adjustments on these engines, they have hydraulic lifter/followers and should not require lash adjustment. Do you have any pictures you could post?

Sounds like a freak racing engine.... could be one of those "mysterious 280" horsepower beasts. Can you photograph the tags, and even better, remove one of the valve covers and get a pic, as best as you can of where the cam contacts the lifter, that will confirm if its hydraulic (no lash) or mechanical (ajustable lash) as darth said, no 3.4 DOHC or any other pre Y2k DOHC engine from GM had adjustable lash.

quote Originally posted by Darth Fiero: Never heard of valve lash adjustments on these engines, they have hydraulic lifter/followers and should not require lash adjustment. Do you have any pictures you could post?

hehehe... eeexactly! I'll give you double what you paid for it!!

do what it says.... then put it in and dyno it... it HAS to be a beast if GM put a label that says only use 100+octane...

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'86 Fiero GT

My Fiero XoticRydz Mid-Rear Madness

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I'll get some pictures later today, but I've never posted any jpeg's before. I'll have to figure that out. Also, I e-mailed GM parts Direct to see if they could shed some light.

Rick

Any updates?

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Alan Frazier
'88 coupe auto 74k miles for sale
'86 GT-'92 3.4 TDC 5 speed(sold)
'84 2m4 daily driver

valve lash means solid lifters on a dohc setup - 100+ octane means higher compression.. i'll bet the cams are either not stock or are timed differently.. this has GOT to be a nice NA build up.. we need specs.. need cam specs.. stick it in a car and dyno the thing.. PLEASE!!!

quote Originally posted by ricksmastermix: ... Also, I'm selling two of my used 3.4 dohc's. If anyone is interested. "One from a '93 Lumina, ~45K mi. and one from a '95 Cutlass, milage unknown. Both engines have good compression, oil pressure and run smooth.

I'd be interested in the low milage motor. Please contact me. My profile have my current email or you can use Pennock's PM. I check both daily. I'll also send you a PM.

Thanks,
Roy

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Roy

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I'm back home from a business trip and hope to get some photos up tomorrow. I hate to remove anything other than the cam cover. Could you tell anything from a photo of the cams? I've checked with a couple of chevy dealer parts depts. - no one has been able to find the part number. GM Parts Direct simply told me the part had been discontinued.

The search for a positive I.D. continues.

Rick

The cam itself is irrevelant, But the appearance of the top of the lifters is more what I am looking for. There would be a step on the edge where an adjustable lifter pad would be placed. If in fact it is an adjustable lifter.
Heres a pic of what I'm looking for. This is inside the cam cover of my crate 3.4 (note the factory assembly grease)

Bump, any word on this yet?

Here are the tags from the new mystery 3.4 dohc engine.

That's really intriguing! The label that advises setting valve lash (?!) and warns to use 100+ octane gas only (!!?!?!) and advises that it's for "Off road, heavy duty use only" (?!??!?!) really makes it sound like there's some special tricks that got included when it was rebuilt. I agree with the other guys - it sounds like it could possibly have been made with solid lifters and high compression. A hi-po race engine? Wonder what kind of power it makes? Do a swap and find out! Heh-heh-heh...

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Chris

Blue 1987 GT Getrag 5 speed, 1" lowering springs, 225 50R16 rims and tires, Fiero Store 9 3/4" HD clutch
SIlver 1986 2m4 THM 125c automatic
Black 1985 2m4 SE Isuzu 5 speed (no paperwork)

Meh, untill you take it apart I dont' think this will ever be solved.

That sticker looks like a generic 100 octane race sticker for a high compression race engine.

it doesnt' even have the same part number as whats on the other tags. I am wondering if this isn't the original crate it came in and was thrown in there for shipping or whatnot.

Thats my guess

SH

Any pics of the engine you could share?

ignore me...

[This message has been edited by ltlfrari (edited 11-14-2004).]

These tags were attached to the engine. The engine is brand new, not remanufactured, according to the dealer. The dealer bought a truck load of engines (Mostly, 4.3L V-6's) in an inventory reduction sale from GM - Detroit. This was the only 3.4 dohc in the bunch.
How would you go about finding 100 plus Octane fuel? Maybe aviation fuel or a fuel supplement?
I'll get some more pictures later in the week.

IF you can find some aviation fuel from some place that is WILLING to sell it to you, I hear you can get 100 octane "hi-test" for about $2.50-$3.00/gal, at least that is what I have heard. I know that you can buy a fuel supplement from speed shops that can convert pump gas to "race gas". We are not talking about off-the-shelf octane booster here, most of those can only bump octane 10 or 20 points, which would turn 93.0 octane into 94.0 or 95.0 octane. The stuff I use is made by Klotz Lubricants and if called "Hi-trate". 1 gallon claims to turn 15-20 gallons of 93 octane pump gas into 107 octane race gas. This is the best stuff I have used and it is O2 sensor safe. Be careful what you use, most "race gas" is leaded and will quickly trash most O2 sensors in less time than it takes to empty the tank.

i need mucho info!!!

http://www.60degreev6.com/index.php?name=PNphpBB2&file=viewtopic&p=39526

I figured I'd see if any of them know anything about it?

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REMEMBER: If you cant win the race you loose the argument!!

3.4 DOHC Motor Swap-14.7 in the 1/4 mile with no hook-up, crumby exhaust and automatic chip.
Better exhaust, chip, cam retarding, and driver to come... I'm feeling lucky!
www.geocities.com/j_depies

Thanks. I'll try for some more photos over the holiday weekend.

Just pull off one cam cover... Take you 10 minutes, and you can measure the lobes, and get an idea as to what you have Don't even need to get new gaskets

When I used to race I would go to the airport and buy fuel all the time. They would bring there truck over to the fence and fill all the jugs that I wanted. If I remember right I was told the AV fuel is 130 octane. At that time it was about .50c higher then pump gas and $1.50 per gal cheaper then Turbo Blue race gas. Also AV fuel has no lubricant and you need to add power steering fluid or Marvels Mystery Oil to run it in a car. I think it would be a major pain to run 100+ octane all the time in a street car. I think the WOW factor is great with this engine but if you do have a special engine what will you do with it. Is this going to be a show car or a daily driver?
Rod

any updates?

Here are some jpg's of the engine and cams.

So far, no help. Those don't appear to be adjustable lifters. Doesn't mean they aren't but they dont have the telltale line around the top. Need more evidence i guess.

I'm guessing that the tags were placed on the engine by mistake. The engine is brand new (Not rebuilt.) At first I thought it might be one of the original GM 3.4 tdc's that had too much HP (275 - 285 hp) for the transaxles used in the z34's, but that engine, surley, would not run on 100plus Octane.
My swap is being done on an '88 cradle with new Held rear suspension, brakes, bushings, etc. I'm using an, almost new, Getrag 284 with it.
Anyone have an '88 engine mounting bracket to sell or trade?

If the dragstrip is still operating in Commerce, Georgia, you can certainly get 100+ octane fuel there.

They're busier than ever. I pass by there every weekend. I used aviation fuel in my Alfa Spiders back in the '60's.

There is no way to adjust the lifter in these engines.

As for off road use only, that is denotaded for racing engines. Certenly thats odd. Also if is a real race engine should be using +100 fuel. But, there is no real racing use before for these engines. At least I neve hear any racing category that use them, most of the race cars use v8. But I could be wrong.

Install it and dyno the car. Is the only way.

Dre