crank work ?

[bszopi]

The block and oil pan will need to be clearanced slightly in order for the rod ends to have free movement throughout the entire stroke. On the 3500 block, there are ~1/8" notches at each rod location on both the block and oil pan.

[montess408]

i e-mailed flatlander racing today about there strokers and they said that it would probly take custom rods and pistons to make it work
and then i e-mailed JBP to find out what they would say about a stroker build and they say that they use stock style pistons and rods
what do you guys think about that ?

[Joseph Upson]

i e-mailed flatlander racing today about there strokers and they said that it would probly take custom rods and pistons to make it work
and then i e-mailed JBP to find out what they would say about a stroker build and they say that they use stock style pistons and rods
what do you guys think about that ?

You can increase the stroke slightly and still use the same piston and rod combo but you are limited primarily by piston travel before interference or extreme compression results. The 60 degree V6 community is still under appreciated in the aftermarket world so not many builders and machine shops have a clue as to what the specs are surrounding the engines or their potential, though I have a feelilng that will change soon as the V6 carries even more of the production market thanks to gas prices.

Pay flat lander $200 to offset grind a 3500 crank, or $425 to add metal and offset grind to a .200 increase so you can use the 5.7" rod in place of the 5.9" and use the same pistons and have yourself a baby stump puller at about 3.7L.

Today I discovered a possible forged production piston for the 3900. The LS1 has the same bore diameter and once you subtract the difference in rod lengths using the shorter LS1 6.098" rod and the difference in stroke .31" using the 3900 5.9" rod and stroke, the LS1 combo drops in the bore from the 9.24" LS1 deck ht, to roughly the 8.82" 3900 deck height provided it is the same as the 2.8L. You would only need to weigh the pistons to assess balance which would be easy since they are floating. Best price ea is about $80 so far through Wiseco and valve reliefs would need to be cut.

The 305 piston is the closest I could find to the 3500 but it would require more work. On the shelf parts are always better than custom in my opinion, especially since everybody wants to sell you special rings with the custom pistons pushing the final cost closer to $800 or more or $1000 if you get a spare. When I blow up a stock piston, I'll start looking into custom, but as long as stock 3800s are doing this on powder metal rods and cast pistons:

http://www.highperformancepontiac.com/tech/hppp_0603_2004_pontiac_grand_prix/index.html

http://www.cartuning.ca/media.php#dyno

I'll take my chances.

LS1 347 piston possibility for the 3900

http://www.jepistons.com/cat/je/auto/chevy_sb/15_ls1.shtml

[montess408]

well thats what i wanted to do grind the crank .250 over and bore .040 to make a 3.7 L displacement so i can use stock rod and stock pistons then right ?
so if 3800 are puting that good of numbers on cast pistons then a good set of hypertec pistons should be fine then i would think ?

[Joseph Upson]

well thats what i wanted to do grind the crank .250 over and bore .040 to make a 3.7 L displacement so i can use stock rod and stock pistons then right ?
so if 3800 are puting that good of numbers on cast pistons then a good set of hypertec pistons should be fine then i would think ?

To be clear, I'm thinking you are planning around the 3500 block which has already been relieved for the the larger crank pins. You will need to first make sure the block will accept a .250 stroke increase and aside from the estimates I did, you also have to make sure the final combination fits properly inside the bore. For example if you increase stroke by .250, and use the 5.7 rods in place of the 5.9 rods in the 3500 block you would still be .050 to high in the bore using the stock 3500 pistons, if you are going custom no problem.

In retrospect, if you are using a 3400 block I would strongly advise you to start with a 3500

[montess408]

yeah i was going to use a 3400 block a guy i know made a 3.7 out of a 3400 that i saw so i wanted to do the same thats why i ask on how it's made becaus where i saw it he does not really specify and block specs just that its a 3400 bored and stroked to 3.7

[montess408]

well looking at it again if i stroke my crank .200 and bore .060 on my 3400 i will end up with a 3670 cc motor and that should round off to 3.7 if i go .250 stroke it will be a 3719cc

[Monzsta]

This has already been discussed here. Good read for a rehash on offset grinding.

http://60degreev6.com/forum/showthread.php?t=38267&highlight=offset+ground

[El_Diablo]

http://60degreev6.com/forum/showthread.php?t=38267&highlight=offset+ground&page=6

and now you know where i got my compression numbers

[montess408]

nice tread but i still dont have the yes or no anser that i am looking for i anm not to good with all this math part of a build so can i stroke my 3400 crank .250 and still use stock 3400 rods and 3.4 camaro pistons ?

[Joseph Upson]

nice tread but i still dont have the yes or no anser that i am looking for i anm not to good with all this math part of a build so can i stroke my 3400 crank .250 and still use stock 3400 rods and 3.4 camaro pistons ?

You may have a problem locating a rod for that combo because increasing the stroke .250 and using stock pistons means you need a 5.45" rod. You will need to measure the clearance of the stock assembly to get an idea of how much room is available for increased stroke.

I'm guestimating that you would be much better off particularly expense and durability wise if you start with a 3500. You are really pushing the limits I believe by trying to massage a 3400 to 3.7L. I would be more understanding if the 3500 was a larger engine dimension wise but since it takes up the same space I would spend the block bore and piston money on the 3500 and stroke the crank to the proper length necessary to use the 5.7 rods with the stock 3500 pistons. Give it some thought

[montess408]

yeah i would love to start off with a 3500 but i have the 3400 already
and i dont have the money to go buy a new block
so what would be the most i could stroke my crank to ? .200 or even less ?

[Monzsta]

nice tread but i still dont have the yes or no anser that i am looking for i anm not to good with all this math part of a build so can i stroke my 3400 crank .250 and still use stock 3400 rods and 3.4 camaro pistons ?

No. The 3400 crank journal is too small. You'd need to start with a 3500 steel crank.

[El_Diablo]

and on top of that your looking at more money for the crank trigger to convert the 3500 crank to one that can be used... and notching the block just to use the STOCK 3500 crank and rods... to be honest im not even sure there is enough room with the 3400 to go that large with the stroke, oh and dont forget you'll need to figure out something for the oil pan aswell

in the end your prolly looking at the same or more to stroke your 3400 than to just go with a 3500, and now you know why i bought mine... so far ive got $100 into it after selling the pistons and rods, not bad for a 30k mile block, crank, cam and timing cover... cam and timing cover will be sold aswell though so we'll see what this really ends up costing me!!

[montess408]

i am not going to use the 3500 crank i want to use the 3400 and get flatlanders to do me a welded stroker i just need to know whats the max stroke i can get with stock length rod and stock style pistons ?
i was talking to jbp on a stroker build and they told me it would be 3000$ for the short block
but they start with there forged crank witch is 1500$ so thats why i am asking for the stroke if i can machine my crank for 450 $ and then get them to do the rest i will save some
$$$ but they did not tell me the bore & stroke numbers