NA 3.8 questions (Engine Pros please chime in)

[WH1Driver]

Is there a crank available that will give me more stroke in a 3.8 or 4.1? I have a engine I want to rebuild as a stroker for big torque but I'm not looking to Turbo it. I was also thinking of doing SFI on it as well, which leads me to ask. Does the FWD SFI 3.8 setup bolt up to a 109 block. What heads should be used with it? The FWD or the 8445? If anyone can give me answers I'd appreciate it. Thanks again.

 

[fuzzyGN]

As far as the intake goes, a friend of mine has tried it and it all bolts up fine (8445 heads, 109 block) but I don't think he ever tried to make it run. Should be a pretty easy conversion. Get the parts from a wrecking yard and give the ECM some power. I too wonder about a stroker crank but the big gotcha will be the custom pistons that are required to make it work.

 

[QuickWrench]

Some answers:

1. There is no OE Buick crank with a longer stroke that will bolt in. Strokes longer than the stock 3.4" unit put you into the aftermarket zone.

2. The 8445 heads aren't RWD-specific. Buick put them on a couple of FWD mid-80's cars.

3. As far as the SFI setup goes, I don't see why you couldn't use a FWD setup. You could probably scavenge a harness, intake, sensors, etc. from an 80-something LeSabre [or similar], or from a newer Firebird/Camaro. Most everything would bolt right up, you'd just need to work out the trans sensor, and some other details. In the end, I think you'd be in for more work than it's worth. I'd stick on the carb, dial in the distributor, and go.

 

[lc2vin7turboSix]

I agree with quickwrench, there will have to some block modification for a longer stroke crankshaft.

probably more work than it's worth. Tune what you got first and go from there. HTH, Jake.

 

[fuzzyGN]

WH1, check your PM.

 

[WH1Driver]

Great info fellas. I have alot of time to do this so I thought it would be a fun project. The whole idea is to build alot of torque via longer stroke to have a real good gas mileage 3.8. I know injection helps with fuel economy so thats my drive to do SFI. I know fuel economy is not a interest of many on this list, I like horsepower at all cost just like the rest of ya in my T but I thought this would be a fun project with my extra 3.8 109 block and heads.
It sounds like a stroker is out of the question now. What are good ingredients for a good gas mileage engine? Feel free to chime in on this one anyone. Thanks

 

[49-blues]

I thought i read somewhere that the coolant passages are reversed on the two intakes making them hard to adapt.

 

[WH1Driver]

Is that true? I have a buddy with a '87 Turbo Riv T-type that he toyed with turbo charging. If what you guys say is true and the heads and intake would bolt up that would give him a big start. He'd have to work with mounting accessories and routing the piping but it could be done it sounds.

 

[1badTTA]

I personally feel that for good gas mileage the EGR system is very important. By injecting spent exhaust gas while "cruising" you are in essence making your engine smaller since a portion of the cylinder is only holding noncombustable gasses and no fuel or oxygen.

HTH

 

[unboostedV6]

While a 3.59 or 3.625 crank from a stage motor will bolt in, the horizontal oil pickup passage in any of the production blocks gets in the way. Of course, you COULD block that passage off at the timing cover, clearance the hell out of it, and run an external pickup tube to the pan... GB

 

[WH1Driver]

Sounds like you have to go to alot of trouble to stroke a 3.8...What does a stage crank run? Probably exceeding the budget on this project.

 

[unboostedV6]

Used $1000 - $2000...New $2000- $2500 GB