Stroker Kits

[turbotony1]

I'm thinking of going the stroker route with my rebuild. I have read many past posts about kits for our cars. Most people agreed that DLS made the best kit.
Is that still true? Do they still make a kit?

I was looking at the stroker kit from Full Throttle. My engine builder/machinist says that tons of their kits come into his shop and that they are great for quality, strength and price. Has anyone had good luck with this kit?

Approximately how many cubic inches will I gain with a .020 stroker kit? (3.625 stroker crank, 5.960 rods)

Is it worth the extra cost for the crank and machining that goes with it? (about $350 for me)

Thanks,
Anthony

 

[Reggie West]

I'm thinking of going the stroker route with my rebuild. I have read many past posts about kits for our cars. Most people agreed that DLS made the best kit.
Is that still true? Do they still make a kit?

I was looking at the stroker kit from Full Throttle. My engine builder/machinist says that tons of their kits come into his shop and that they are great for quality, strength and price. Has anyone had good luck with this kit?

Approximately how many cubic inches will I gain with a .020 stroker kit? (3.625 stroker crank, 5.960 rods)

Is it worth the extra cost for the crank and machining that goes with it? (about $350 for me)

Thanks,
Anthony

Weber racing is another source for the stroker kits as well. I would buy a forged rotating assembly meaning rods and pistons with whomever you buy the parts from.

You have to do the machining on all of the parts. The crank can be out of round right out of the box. Doing a stroker crank will require some clearancing on the skirts of the block too. Watch out for it.

Tolerances are everything with these motors. Send it to a competent BUICK machinist. Full throttle or DLS will do it right. Do not trust a small block chevy machinist with it. The results are not pretty.

Good luck

 

[Nick Micale]

First of all, the stroker "kits" all are just about the same from the various vendors. The forged cranks and rods are from China, and they are some of the very few off-shore parts that are worth the $$$.

Second, unless you plan to build an engine over the 700 HP and 7000 RPM level, you will never feel or be able to use the relatively small increase in performance with a 109 block.

Personally, I have build and used many stroker V-6's over the years and that is my findings.

Want more street torque and HP, just go with a 4.1 block with the bigger bore, better breathing. The bore vs. stroke discussion with a Buick engine traditionally has always favored bore by a large margin.

 

[turbofabricator]

First of all, the stroker "kits" all are just about the same from the various vendors. The forged cranks and rods are from China, and they are some of the very few off-shore parts that are worth the $$$.

Second, unless you plan to build an engine over the 700 HP and 7000 RPM level, you will never feel or be able to use the relatively small increase in performance with a 109 block.

Personally, I have build and used many stroker V-6's over the years and that is my findings.

Want more street torque and HP, just go with a 4.1 block with the bigger bore, better breathing. The bore vs. stroke discussion with a Buick engine traditionally has always favored bore by a large margin.

That conversation is worth visiting. Yes bore helps breathing AND it adds torque significantly. As if pressure remains the same, the force applied to the piston increases with diameter. (Force= PSI X Pi R squared) BUT........the added stroke will also increase torque due to a longer wrench turning the flywheel. PLUS the longer burn rate with a turbocharged engine (more air and more fuel= more burn time and pressure) The farther the burn rate is in relation to the torque arm of the crank (look at it this way...when you torque a bolt, do you put the wrench at 90* or do you grab the wrench with the handle away from you at 12 o'clock) So with pressure pushing a longer arm of the crank, it should, in theory, make measurably more torque. BUT.....with the typical gasoline engine reaching peak cylinder pressure at 11*-16* AFTDC, and the flame front done at 27*, all this makes for interesting debate. Then add to the mix the poor little hampsters running their asses off, what kind of hampster chow should we use?

 

[turbotony1]

Very interesting stuff! I don't think I'll be going to a 4.1, but I like the advise.

Thanks guys.

 

[Nick Micale]

...... So with pressure pushing a longer arm of the crank, it should, in theory, make measurably more torque. BUT.....with the typical gasoline engine reaching peak cylinder pressure at 11*-16* AFTDC, and the flame front done at 27*, all this makes for interesting debate. Then add to the mix the poor little hampsters running their asses off, what kind of hampster chow should we use?

You lost me with the hampster chow part Ken? :biggrin:

From the big block Buick V-8 days, we found the additional breathing far outweighed the longer stroke. Buick went from the 400 cu.in. V-8 to a 430 and finally the 455.

Crank and stroke are all the same, just the bore increased in diameter. Comparison to the 455 olds and Pontiac engines, Buick way overpowered them in torque

With the V-6 turbo engines I have replace some 3.8 blocks with 4.1 using the same cam and heads as well a same stroke, and see BIG increases in torque.

My opinion, this is due to better breathing

 

[turbotony1]

Are 4.1 blocks hard to find? I don't hear a whole lot of people running them.

If I were to go to a 4.1, would a 3.8 crank rods and cam work with that block?

What other parts or pieces don't work universally? (obviously pistons have to be bigger)

 

[Ed Valvo]

What RPM's are people safely running with these stroker engines? Is 6500-7000 RPM asking for too much?

 

[Squid4life]

Are 4.1 blocks hard to find? I don't hear a whole lot of people running them.

If I were to go to a 4.1, would a 3.8 crank rods and cam work with that block?

What other parts or pieces don't work universally? (obviously pistons have to be bigger)

Can be found at a pick-a-part. Try to find a 291 block, (casting # ending in 291) but check the deck around the head bolt holes.

Can use the same crank and rods as the 3.8, but you will need a 14 bolt oil pan and front cover. Actually most newer front covers are made to accept 20 or 14 bolt pans. The donor motor should have both those parts. Look at everyones sigs on here, you will see plenty of 4.1's.

 

[turbotony1]

Love the comments! Thanks

Back to my original question, does DLS still make the stroker kits everyone was talking about?
How about Full Throttle's kit? I like the price!

Thanks.

 

[Squid4life]

Last I think I read on here DLS wasn't selling them outright, only with a motor from them, but that could have changed.

Give each of them a call to be sure. See if you can get them to ensure they are "drop in" ready or close, but be ready to take them to at least get checked. Many of them still require a polish or .010 turn.

 

[INEEDAGN]

Before you decide on a 4.1 you need to look into pistons. Last I checked there were no commonly available forged pistons and you either had to run hypers, used stage II stuff, or custom forgings.

 

[Pronto]

This might answer your question:
http://www.turbobuick.com/forums/engine-tech/311157-new-combo.html

 

[Squid4life]

Before you decide on a 4.1 you need to look into pistons. Last I checked there were no commonly available forged pistons and you either had to run hypers, used stage II stuff, or custom forgings.

I remember way back when, when I got that 4.1 from Brian's dad, I was told you could probably find an off the shelf forged piston for a SBC that would work. As long as the block sonic checked ok, bore it to match the piston. (~4" bore.)

I think Pronto is trying to say "no need for a stroker". :biggrin:

 

[Pronto]

Or 4.1

 

[DR BOOST]

when in doubt, do both. a 4.1 with a stroker kit...274 cubic inches

in regards to the stroker kit in a 3.8...why not..for 350 dollar difference , id go stroker any day.

 

[Jeff Rand]

I have built a number of stroker motors and used the kits from Full Throttle and GN1 Performance. The Chinese crank journals need to be checked out first before any other machining is done. The last kit that GN1 provided to me (about three weeks ago) had a 3.625" crank that did not have to be machined which was very surprising.
Jeff

 

[Reggie West]

What RPM's are people safely running with these stroker engines? Is 6500-7000 RPM asking for too much?

The T Type shifts at 5800 to 5900 and it has no problem with it. I would think it would be OK to do that but would there be any usable hp at at that level? You would have to have a cam that would make some power up there and the 212 in this motor would not produce anything up that high.

Just my 2 cents Ed.

 

[WhiteTtype989]

Can be found at a pick-a-part. Try to find a 291 block, (casting # ending in 291) but check the deck around the head bolt holes.

What were the common vehicles to find the 291 block in

 

[Onalky87]

Can be found at a pick-a-part. Try to find a 291 block, (casting # ending in 291) but check the deck around the head bolt holes.

What were the common vehicles to find the 291 block in

1980–84 Buick Electra, 1980–84 Buick LeSabre, 1982–84 Buick Regal, 1981–84 Buick Riviera, 1980–82 Cadillac DeVille, 1981–82 Cadillac Eldorado, 1980–82 Cadillac Fleetwood, 1981–82 Cadillac Seville, 1981–83 Oldsmobile 98, 1981–84 Oldsmobile Toronado, 1982 Pontiac Grand Prix, 1982 Pontiac Bonneville