My first stroker

[jason alexander]

Hey guys hows it going,

Long time reader just getting around to building my first stroker just wondering if you guys could give me some advice but first here is my parts list

KB944 pistons 30 over
4.0 rods
std rods bearing
std mains bearings
new scat crank
victory gasket set
new melting stock cam and timing set
high flow oil pump
not planing on doing alot on machine work just magnaflux check for cracks and bore and do some head work... this is going in a 2001 jeep grand cherokee
21 lb injectors

here is my big question can i run 87 at 900-1000 ft above sea leval
or what do i need to change to run 87 or 91 rather stay lower.

would you guys put new rocker arms on it or reuse the rockers that where on the old engine the reason it was bad is it had a broke piston skirt in 3 or 4 cant remember what one. anyreason not to blow air throuh the push rods and not use them? and i problably need to replace lifters when i do cam is this correct? any other input would be great!

Thanks Jeep Strokers!

[doublins]

Serenity now! George was the best on seinfeld.

[Retlaw01XJ]

new scat crank
...
high flow oil pump
...
21 lb injectors
...
here is my big question can i run 87 at 900-1000 ft above sea leval
...
reuse the rockers
...
push rods
...
replace lifters
...
Thanks Jeep Strokers!

Sounds like my 01 XJ build, except I used a Crower 44243 cam..... Just a little more cam than stock to feed the extra cubes!

Measure the main bearing journals on the Scat crank. Mine were a bit undersize so I used Mopar 0.001" undersized bearings. Clearance was about 0.002 with those , but would have been 0.003" with standard bearings.

A standard oil pump should work fine if bearing clearances are right. A standard pump also puts less load on cam and drive gears since it's easier to turn.
Hi volume pumps are better suited to engines with loose clearances to keep oil pressure up.

Larger fuel injectors are recommended.... especially to keep the engine from pinging at WOT.

Mine is happy with 89 octane. Haven't tried anything lower yet. Cut my block 0.020" to raise the CR to 9:1. I'm near 400 ft.
I'd guess you'll be fine with 87 if it's running cool.

You can reuse rockers and push rods if they are in good condition.

Definitely get new lifters for the new cam!!

[SilverXJ]

Larger fuel injectors are recommended.... especially to keep the engine from pinging at WOT.

x2 you don't want to use stock injectors. You may not hear a ping at WOT, but with out an AFR gauge you don't know what is happening. And it can cause damage w/o pinging.

[superj]

man, i know about 4 people named jason alexander, ha ha ha. do you live in texas? i know you are not near me because i am only about 5 feet above sea level but i know a jason alexander in san antonio and in livingston texas.

sorry to go off topic, no introduction thread to ask these questions in

[jason alexander]

Sorry i meant ford 24 lb injectors do u guys see any reason this wouldnt run 87? Any advice for this build. Also what over bore would u go on the kb 944 4032 alloy would u go with the street ot tow over bore?

[SilverXJ]

I doubt it. Last time I tried 87 on my KB piston stroker it pinged. I haven't tried it recently though.

The over bore really is the amount that the piston is over sized, .020", .030", etc. What you are talking about is piston to wall clearance. I would go with .0030"-.0035"

[jason alexander]

What do u think i would have to run 89 or 91 or something else and could a head spacer shim prevent the pingwith 87?
Do u guys have a link to a thread about pinging, gas used and how it is related to compression ratio?

[SilverXJ]

A head spacer/shim (they don't even make such a think for ours) won't help because you will be increasing quench. I don't know of any website that can give you a definitive answer on octane vs. SCR vs. DCR.

[jason alexander]

The reason i was asking is because i saw this on rock auto they labled it as a cylinder head shim.
http://www.rockauto.com/catalog/moreinfo.php?pk=1828652

entered my infomation into the compression calculator on summit and it came out to 9.44:1

Entered all the information in jeep stroker calculator here is what I got
SCR 9.26:1 DCR 7.97:1 Quench .0645 Intake Valve Closeing angle 53.95