3500 Top End Swap Complete

[AaronGTR]

I have never heard of anyone using shorter rods in a stroker motor, in fact they usually wouldn't work, due to the simple fact that at BDC the distance between the piston skirt and the rod journal is increased over a shorter stroke design, so decreasing the length of the rod will make the crank counter weights smash the piston skirts.
The pin hight (compression hight) is usually changed to off set the grind and no, it's not by the same amount of stroke increase, it's by half that. Simple geometry here.

You're right, it's half the distance of the stroke. I guess wether or not you can shorten the rods though depends on how much clearance you have to being with.

I have heard of using shorter rods. I guess it depends on the kind of engine you're working on. Some engines have more room between the piston and crank. Some engines the stock piston pin position can't be moved enough to make up the stroke difference by itself so you have to use a combination of moving the pin and shorter rods. Sometimes they just change the rod length looking for a different rod ratio. Maybe all this doesn't apply to a 60v6. I haven't built the internals on one yet so I'm not familiar with all the measurements. I've read about lots of engine builds though so I know it is done on some engines.

[mcgavinz26]

Even though you guys are going to come back with the complexities of doing the swap, i'm going to make the joke anyways....

forget working to get to 3.7, i heard GM is going to be coming out with a 3.9 60 degree soon

[onefastV6]

The 3.9L has been out :P

[onefastV6]

Update: I am getting the tuning closer and closer. At WOT the car pulls very hard and I am only registering 5* of KR. I plan to take the tranny mount off and fill it with urethane and see if that helps at all. I am hoping I can have everything in check and running perfect in another month or so and then jump on the dyno to see what the real results are.

My first dyno with only the borla cat back, dynoed a best of 143.2 HP so I atleast have something to compare it to. I can tell there is alot more power than before, so I am anxiously awaiting the results as well.

[bonecrrusher]

What head gaskets did you use in this swap??

PM sent too....

[onefastV6]

I bought the complete top end gasket kit, which included the 3500 gaskets

Check out the link which is complete with pics of the gasket set and part #

http://60degreev6.com/showpost.php?p=293134&postcount=18

[mcgavinz26]

Going back a few posts, "yes, that was the joke".

New dyno numbers yet?

[EspanolaGuitarista]

On stroking....

I have crunched the numbers. If you increase displacement you will NOT have the airflow requirement to support it. It won't be a high-revving motor. I'm thinking 5200 rpms like the stock but with more horsepower and torque, but you would need a big cam with lots of lift(i.e. 0.600+) and possibly a tighter LSA like 108. A stroker with a the Stage II Milzy would work well and full porting. I would max out the valve size on the intake side and bump the CR up to 11:1 to offset exhaust flow. If someone has a desktop dyno and can input .250 more stroke and see what happens, that would be interesting. Moving the pin up 1/8 of an inch would not put you into the oil ring, but I don't know that for a fact.

[onefastV6]

Going back a few posts, "yes, that was the joke".

New dyno numbers yet?

No new numbers yet, I have been busy with work. The car is running great though and the tune is about 75% complete, but will always be a work in progress.

[IsaacHayes]

Still tuning? Get that sucker done!!! _whip_!

[bonecrrusher]

Thanks for the part number, I ordered it from Paceparts.com for 140 shipped to my door.

GM wants 185 for the gasket, and GMPD wanted 110, but there shipping blows my ass and is slow..... I need the gaskets now, not 4 weeks from now.

Thanks again!

[95SleeperAcheiva]

the arguement goes....

increase stroke at the crank, shorten the rods, same piston, less reciprocating weight. ie stroker/ increase in cubes.
or
same stroke, longer rod, shorten piston and move pin up on piston, less reciprocating weight at the end of the rod. ie less stable piston but a faster wind up and more power.

whats better? they been arguing this one for years.

I'm working on the 3900.

I'm most likely going for a complete motor, and obd2 swap. since I have this damn transmission from raptor trans 4t65e that I have been wanting to put in for over a year!!!! I want some software!!!! ODB2 programming software!!! AAAAAAAAAAAAAHHHHHHHHHHHHHHHHHHHGGGGGGGGGGGG!!!!!! !!!!!!!!!

[IsaacHayes]

Does anyone even make a powertuner/etc for a 3900 car? Even without the VVT cam and intakes, you should still make at least 200 hp stock I'd say. Not sure how the intakes work but you could probably rig something simple up at least. The VVT cam isn't like a 94 honda vtec, it's truly varible either direction.

[SappySE107]

The 3500 makes 200 hp stock.

[tejohnson]

I'm most likely going for a complete motor, and obd2 swap. since I have this damn transmission from raptor trans 4t65e that I have been wanting to put in for over a year!!!! I want some software!!!! ODB2 programming software!!! AAAAAAAAAAAAAHHHHHHHHHHHHHHHHHHHGGGGGGGGGGGG!!!!!! !!!!!!!!!

For the 3900, it is in all the newer vehicles, which are CAN. I think DHP is just on the tip of releasing a CAN interface, which would support al the later model vehicles.