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95 Buick Roadmaster

Skydrol

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I though some of you guys want to see this USA Made Land Yatch (build in Texas). Is my mum in law, had it since new. Has a LT1 5.7L Multiport Fuel Injection and some that perhaps nobody seen it in the Holden world as far I know. Is an interesting piece, a distributor called "Optispark", you guys can search on it. I am working on it because it has 117,000 miles and a weird hesitation at light loads at about 63 MPH/80 KPH. The engine seems to have a slight miss, very anoying.

Anyway, here are some pics of this boat.

20200822-191316.jpg


Check the engine bay. That is a LT1 5.7 V8 and how much room has between the engine and the fans.

You see the crank pulley? On top is the water pump, behind that, the dreaded Optispark. I hope is fine because is a bitch to get to it and a very expensive timing device. Not sure, but I think this is a milder version of the Corvette engine, this big boat can move. I bet, a nice 427 Big Block or a ProCharger with an Intercooler will fit nicely.

20200822-191421.jpg



20200822-191458.jpg
 
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Skydrol

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Indeed... not sure where this guy is going to end but if I get it, the LT1 is out.
 

shane_3800

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That engine is yuk. My old chevy power book had a chapter on LT1 tuned port engines the gen two was a nice engine in sports cars this one looks like poo to work on. I can see EGR and a few other annoying things then you mention the optispark is driven by the cam sprocket mount yuk yuk yuk.
 

Skydrol

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Yes, is directly mated to the cam sprocket. In theory is a great idea, 0 maintenance and all timing is done by the PCM. Also, the light sensor is much more accurate. The problem is Ozone created by the rotor. On earlier models were sealed, later ones, has a vaccum line to vent the Ozone. Saw a kit that replace the distributor for a 4 coil Waste Spark system, but still uses the Opticspark sensor for timing.

Another thing, the plug wires... another PITA to get to them. They run from behind the Waterpump to the cilinders housed on some sort of Tubes and Plastic conduits. No easy task from above, can hardly see them, I bet is done from the bottom of the engine. Also the Plugs, the manifold is upside down and covers the view to some plugs. #2 is impossible to see and to reach it, you need like 60 cm extension with flex joints and do it only by touch.

I am afraid to wash this engine and start acting up.

The top on the intake manifold, that triangular thing. Is not a filter, is a hollow cavity. I bet is for noise reduction and nothing else.
 

Skydrol

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Today, tried a little troubleshooting on the beast. After changing the fuel filter, some hesitation went away, still there some. Thinking about replacing the plug wires. Looks like they are the factory ones. Took some pics of the Optispark and the leads.

That is one bank.

20200823-144652.jpg


The other bank.
20200823-144748.jpg


If you want to do a show car build and want to hide the plug wires, consider an Optispark. They are hidden from plain sight.

Is going to be a bitch to replace them and most definite, from the bottom of the car. I wonder, how much a mechanic will charge for the job?

Took other pics.

The EGR and the FPR are located at the back of the intake. The big valves on the sides are for the Smog Air Pump. Is dual exhaust with dual cats. Checked for vaccum leaks, could not find any.

20200823-144813.jpg


Went to check the ECM with my code scaner, to see what the sensors read. Turned out, the ECM is ODB1, perhaps is the last year of the ODB1. Read at the bottom right, no wonder the plug (ODB Port) is different, I thought it was a proprietary port of the era. Only maintenance, plugs and "mind the gap".

20200823-144912.jpg


Some interior pictures. Keep in mind, this was a premium car in the mid 90s. On the passenger door, there is an ashtray and also on the rear on each side. Some that is not available on any car now days.

20200823-145644.jpg


20200823-145712.jpg


20200823-145657.jpg


More room in front of thr radiator... a nice intercooler will fit with no much drama. That is a factory heavy duty transmission cooler (towing package).

Would be nice if Al and Woody get their hands on this car.

20200823-145822.jpg
 
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the_boozer

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If you want to do a show car build and want to hide the plug wires, consider an Optispark. They are hidden from plain sight
thats no show car engine haha . Looks like a job from hell has it ever had a set of leads in its life? You got alot of work to do to fix that thing properly all reading I've ever done about Optispark says it was **** when it was new, an engine the GM workshop manual says not to put the hose on isn't something I would ever want to put my hands on lots of plastic pieces to break is what pisses me off about 90's cars.
 

Skydrol

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Of course is no show car engine... I said, if you want a show car and the plug wires hidden, out of sight, to consider (keyword "consider") an Optispark. Is just for the looks.

Oh no, as daily driver, no way in hell will put that in.

I understand the design but GM already had a reliable waste spark system and why not install it in this engine is beyond me. All I can think of why they decided to do it is the accuracy on the light sensor approach, instead of magnetic sensors and maybe, snatch a powerplant package from the Camaro/Firebird assembly line and call it a day.
 
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shane_3800

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Of course is no show car engine... I said, if you want a show car and the plug wires hidden, out of sight, to consider (keyword "consider") an Optispark. Is just for the looks.

Oh no, as daily driver, no way in hell will put that in.

I understand the design but GM already had a reliable waste spark system and why not install it in this engine is beyond me. All I can think of why they decided to do it is the accuracy on the light sensor approach, instead of magnetic sensors and maybe, snatch a powerplant package from the Camaro/Firebird assembly line and call it a day.

AC Delco probably designed it and they decided to do a run to see if it was a better option. The accuracy is on par to LS1 reluctor wheels.
 

Skydrol

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Perhaps, agree that is like a real time test. A good idea, not a good design and that is why they are gone for good.
 
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