will this setup work?

[ftpiercecracker1]

First time building a stroker, second time building an engine.

stock 258 crank 12cw
stock 258 connecting rods
stock 4.0 pistons
stock 4.0 pushrods

block will be .030 over (maybe .060)
88 4.0 block (receiver)
79 4.2 block (donor)

Can you tell by this setup what cam i will need?
Don't care Don't care if i have to use high octane usage.
heavy offroad use, trails, lots of mud, very little crawling.
think offroad rally/mud drag (South Florida location), From what I have read even if you setup your motor for mostly top end you will still have a pretty nasty bottom end. sound right?

would like to keep it at or under $2,000

thanks for the help.

[Missourian]

Look for yourself at this link as these are proven set ups .

[ftpiercecracker1]

already been. doesnt give the answers i need
its says something about rods, but does not say whether they are push or connecting
where can i find pistons for a block .030 over?

[Missourian]

OK.

Rods are specific to the connecting rods of the engine either 4.2L or 4.0L.

You will reuse your 4.0L push rods with your new cam and lifters once you machine your engine and its components. You will most likely reuse your head perhaps after it being freshened up (a.k.a a head job).

http://www.SummitRacing.com will have the pistons you want.


The nuts and bolts (simple terms) the link is what you need to follow for selecting parts for your build.


I personally selected the "Modified Poor Man's" 4.6L STROKER and you have most of the components for that having the 4.2L crankshaft, 4.0L Connecting Rods, then you need Keith Black 944 +0.030" Forged Pistons and a larger flow rate Fuel Injectors and you should be ready to head to the machine ship with your engine and start prepping your engine for rebuild/STROKIN'.

[ftpiercecracker1]

sweet, thanks for the clarification.
and as for the head, i was told that i have to use my 90 model head and intake man in place of the 88 head.
88 carbed
90 injected

[ftpiercecracker1]

sweet, thanks for the clarification.
and as for the head, i was told that i have to use my 90 model head and intake man in place of the 88 head.
88 carbed
90 injected

[ftpiercecracker1]

i cant find the KB 944 pistons on summit.
they have a bunch of his stuff, but is 944 only part of the ID #?

[yuppiexj]

Here you go, but they seem to not stock them anymore.
http://www.summitracing.com/parts/UEM-KB944-030/
http://www.summitracing.com/parts/UEM-KB944-060/

They list a substitute part #
http://www.summitracing.com/parts/UEM-IC944-030/
http://www.summitracing.com/parts/UEM-IC944-060/

[ftpiercecracker1]

awesome, thanks for the direct link.
Just out of curiosity would it be worth it to "shop around" for these pistons?

thanks.




now, about that cam. . .

[ftpiercecracker1]

OOhh, my heart! I just looked at the link you gave me and nearly had a heart attack. Is there no other way? Those pistons are just so UNbelieveably expensive!

Here's an idea, what if I used stock 4.0 pistons, same dia and all, just have the cylinders honed. How big of a loss would that be? displacement, HP, torque?

[SilverXJ]

What did you expect? They are forged semi-custom pistons. That comes at a price.
If you want to use the hypereutetic cast 4.0L pistons you will need to use the 4.2L rod. The KB/IC pistons use the 4.0L rod.

[ftpiercecracker1]

ya, i guess. but still

[ftpiercecracker1]

ok, now there is one other thing i have to ask. what is the deal with
"pin height", do i have to worry about that with these pistons?

[SilverXJ]

Pin height(aka compression height) is the difference between why the KB pistons need the 4.0L rod, why the 4.0L pistons need the 4.2L rod and why you can't use a 4.0L rod and a 4.0L piston in a stroker. Its the measurement from the center of the wrist pin to the top of the piston. For example: Using the same crank, block stroke, rod, etc and only changing the pin height will change where the top of the piston is in relation to the top of the block. Too great a pin height and the piston will stick too far out of the block (4.0L rod + 4.0L piston), too small of a pin height and the piston will be too far down in the block (4.2L rod + KB piston)

[ftpiercecracker1]

well then knowing that, wouldnt it be cheaper to just get the oversized 4.0 pistons and use the 4.2 pushrods (i have on hand), Instead of paying the 424 for semi custom pistons?

or do they not make .030 over 4.0 pistons?

thanks for the clear and concise post, i really appreciate it.