3500 crank

[IsaacHayes]

Ok Superdave, we know what next years build will be for you. 3900 bored/stroked to 4.3l, cammed', headers, with variable intake on a RPM switch. Goal: 450hp.

[zofo61]

If it is possible........I would REALLY be interested in the stroked 3400. I am not so good with theory...but I am real good with ...a YES or a NO. I have a 3400 short block and a Complete 3500 on its way.........just what would be the first order of detail to get this to be a reality? I have a local machine shop that can do ANYTHING...I just need to know from you guys if this is doable an/ or worth bothering....or should I just put the 3500 topend on the 3400 bottom and call it a day?

Wadaya think?.........does anyone have the numbers that Diablo needs?

[El_Diablo]

i say keep the 3500 crank in the 3500 block and stroke that... thats my plan if i can get all the numbers to work out, which is where i fall short

[ForcedFirebird]

Ok Superdave, we know what next years build will be for you. 3900 bored/stroked to 4.3l, cammed', headers, with variable intake on a RPM switch. Goal: 450hp.

I like the idea, but with boost .

[El_Diablo]

and a higher hp goal

[IsaacHayes]

Bah! N/A big numbers is the goal!

[zofo61]

Ive been talking to Sappy as well about swapping the 3400 in 2002 Monte with the 3500/.........what would be the main issues with the harnessesand PCMs?..................what would I have to do to the 3500 to stroke it out?....I have one comming and I want to do the most with the 3400 I have and the 3500 thats comming...........remember I have that RSM Blower Kit sitting on the floor as well...........

[Joseph Upson]

Ive been talking to Sappy as well about swapping the 3400 in 2002 Monte with the 3500/.........what would be the main issues with the harnessesand PCMs?..................what would I have to do to the 3500 to stroke it out?....I have one comming and I want to do the most with the 3400 I have and the 3500 thats comming...........remember I have that RSM Blower Kit sitting on the floor as well...........

Stroke the 3500 crank with an offset grind to the 3400 rod journal size, then use the 3400 rods with the 3500 pistons. Since the rod length difference is .200, and the offset grind should be able to get you ~.125" increased stroke or closeness to the cylinderhead, the pistons will sit about .075" lower in the bore, considering the 3500 crank journal diameter is .250" thicker than the 3400 crank journal and you have to halve the diameter of the circle to get the amount you can offset grind the crank by without adding metal.

Not sure how much it will reduce your compression by but it should be perfect for boosting. Of course you can perfect it with custom pistons to restore the stock piston to deck height but if it isn't necessary it will save you quite a bit of doe.

[zofo61]

Stroke the 3500 crank with an offset grind to the 3400 rod journal size, then use the 3400 rods with the 3500 pistons. Since the rod length difference is .200, and the offset grind should be able to get you ~.125" increased stroke or closeness to the cylinderhead, the pistons will sit about .075" lower in the bore, considering the 3500 crank journal diameter is .250" thicker than the 3400 crank journal and you have to halve the diameter of the circle to get the amount you can offset grind the crank by without adding metal.

Not sure how much it will reduce your compression by but it should be perfect for boosting. Of course you can perfect it with custom pistons to restore the stock piston to deck height but if it isn't necessary it will save you quite a bit of doe.

Now thats the kind of info I needed to get rolling......................now if I am going for around 350 HP to 400 MAX( and thats optimistic) I should be able to use the stock 3400 rods and some forged 3500 pistons.....YES?

[IsaacHayes]

Rods should be good for 350-400 crank HP. Others have dyno'ed 350ish wheel HP before on stock 3400. Pistons are the main thing, but if you have a good tune then you should be good generally.

[zofo61]

What is the difference in diameter between the 3400 and 3500 pistons and I assume the 3400 block can take the bore?. Anyone have a line on forged 3500 pistons...............Ive been reserching a top coating as well..............think a little more lift and duration as well.....and would one of Bens regrind stages fit this combo?

[blkalero]

So let's have the gory details.. Where did the block get in the way, any other clearance issues, and what did the pistons cost? There's a 3900 on ebay right now for $1,200... might be time to go hunting..

Being stroked 10mm requires the crank throws to be ground down as well as the block.
looks like there will be enough meat left without hitting a water jacket to clear the longer throw.
Thats kinda where I lost the extra cash to finish.
pistons were $735 I believe with rings. (JE forged) broke down to like $600 for the pistons and $135 for rings.
I went with manley rods forged I beams good for 750hp ish.
I decided on the I beans due to them being lighter than the H beams.

I wanted light and strong. this caused the price to go up I could of goten cheaper rods and saved a few hundred or more. I believe the set of six after mods ended up being close to 900 or more.
if I had to do it over I'd go like 6mm instead of 10

[Monzsta]

Why would the crank throws have anything to do with it, other than to clear the piston? Couldn't the pistons be profiled to clear them?

[Joseph Upson]

What is the difference in diameter between the 3400 and 3500 pistons and I assume the 3400 block can take the bore?. Anyone have a line on forged 3500 pistons...............Ive been reserching a top coating as well..............think a little more lift and duration as well.....and would one of Bens regrind stages fit this combo?

Actually I meant to imply you use the 3500 block rather than pay to have a 3400 block preped to fit the pistons and crank. There were two sets of 3500 forged pistons on EBay about 2 months ago for a reasonable price that would have more than restored compression ratio with a .075" shorter compression height.

[blkalero]

Why would the crank throws have anything to do with it, other than to clear the piston? Couldn't the pistons be profiled to clear them?

with rod length givin and piston pin placement they didn't clear.
this is why I dont recomend going 10mm. less of a stroke woukld be fine