I'd do the following:

1. Drop the pan.
2. Drain the oil.
3. Drop the pan.
4. Examine the oil for filings, metal, etc.
5. Put a ratchet on the crankshaft pulley.
6. Slowly rotate CW the engine by hand.
7. Feel for any type of resistance.
8. If you encounter some, back the rotation past the area and repeat steps 6 & 7.
9. Mark the spot on the crankshaft where the resistance occurs.
10. Rotate again to confirm the resistance and spot are aligned.
11. Progressivly loosen the Main bearing bolts to lessen pressure on the crank.
12. Repeat step 6 - 9.
13. Continue setp 11 untill the resistance dissappears.
14. If the resistance does not dissapear, then the problem's in the head.

15. Remove the Valve cover.
16. Remove pushrods one at a time, repeating steps 6 - 9.
17. Repeat until the resistance lessens.
18. If the reistance does not lessen...

Humm... I think it's a wrist pin....

OK... these are only how I'd do it... of course you're free to modify!

Good hunting.

 

Chris you said hard to start. Where is the timing set. Is it spark knock.

 

leve, thanks for the reply...
heres why i dont think its a wrist pin..
well.. it could be...
when I say its hard to start, I dont mean it cranks slow.. it cranks fine..it just doesnt like to start. when i was looking for TDC on the engine, i cranked it over several times by hand and there were no hard spots...
the rods are all new and I had a very reputable shop install the wrist pins. I examined them and they were all free before instillation.
I checked everything with plastiguage and all tolerances were perfect.
I would be pretty confident that theres nothing wrong with the bottom end.
hmmmmmm.
how aboput this.. the cam was broken in the engine(half of the broken connecting rod hit it) might it be a bent valve?
it was #6 that broke, and the sound seems to be comeing from the front...

 

spark knock??? hmmm.. could be.. i cant set the timing.. its a 97.. its pretty loud to be spark knock.. how can I tell?
should i dump a couple gallons a race fuel in and see what happenes?
BTW... I have only run the fresh engine for about 20 min total.

 

Chris is the knock sensor good. Maybe it broke or just plain old went back. I have heard spark knock sound like a rod coming throw the side of the block.

 

Sounds like it could be the dreaded pinging....It sounds horrible like something will rattle through the block. That's how I ruined a perfectly good 258 block.

Maybe you can cheat the crank position sensor a little retarded from it's normal position to trick the engine as to TDC. Also, pull the vacuum hose from the fuel pressure regulator so it thinks it has to put more fuel in for Wide Open Throttle vacuum. Have you increased it's ability to dump fuel?

Also, are you running the cooler plugs recommended with the 4.0 head on a 258? What rods/pistons did you go with? Is the crank a normal grind and polish or is it offset.

These are just ideas to see if it is spark knock. You can take some degrees off the computer (I think it's 4 degrees) and you will most likely need an adjustable fuel pressure regulator. Do you know the rating for the injectors you're using? You can crank up the pressure and get more fuel, but only to an extent based on the injector rating. Most strokers are happy with 22-24lb injectors.

Hope this helps.

 

What??? You rebuilt an engine that had thrown a rod and broke a camshaft, and you didn't disassemble and inspect the head??? Shame on you!!!

 

"and put the pushrods exactly in the same place they came out. "

i just had a thought! i could be a bent pushrod (or 12) not allowing a valve to open and its is getting slapped around by both the lifter and the rocker. i'd pull the valve cover and do the "screwdrive to the ear" trick to look for the noise. you may need to get some oil deflectors (has anyone ever tried aluminum foil for this?).

matt

 

any news on the stroker? i'm wanting to do this to the 4.0L that i'm putting in my 1963 willys wagon.

matt

 

Chris,

Sent you some info on your email. The forum reply box has been hiding from me. Hit refresh and all ok now!? Anyway.

1. Check the cap to rotor position. Can cause crossfire.

2. Some of the aftermarket cams have a smaller base circle that require longer pushrods.

Jackie

 

that's a 4.0 block, right?
i just fired up my new 4.2 w/4.0 head.
ALL the rockers sounded like they were rattling.
they seemed to be slightly loose.
i pulled each set and ground off about .03-.04" off the bottom of each fulcrum (?)to bring the pushrod down into
the lifter some mo (non-adjustables SUCK!!!).
this shut it up about 90%.
it didn't seem like i needed longer pushrods, or diff rockers, just that it needed a little more lifter pressure.
and....the '97 4.0 head was stock, the deck was untouched.
wtf??!! anyway, i still have a little rattle, and
what i thought was bearings before, must be in my tranny.
THAT rattle's still there. owell.

 

this is a total guess but is there any clearancing that needs to be done since you've added a longer rods? I've heard that sort of thing happens in stroked chevy engines. JAT

 

Richard, the pistons go about 1/2" further down in the cylinder, but are .022 lower than they were at the top.

heres more info i posted on the yahoo stroker board....


I have it running perfect except for the most
hellatious knocking. I have 90+octane and I changed to the cooler
plugs with no difference.
when I first fire the engine up, it taps a bit until it runs for
about 1 min. then the sound changes and becomes a good knock.
I tried playing with the timing, I checked and rechecked the fireing
order, tdc, etc.
I have run the engine for about 1/2 hour total now. it really does
run well except for the knock, though it cranks for awhile before it
starts.
since i got absolutely no results from anything i did, I began to
think maybe it wasnt spark knock, so i pulled the valve cover looking
for something wrong... of course, it all looks perfect.

even more info.....

I dont think it's spark knock anymore.

I'm still curious as to why the sound changes 30 sec after it
starts.. something about the lifters pumping up?
I think that it isnt 1 cylinder making the noise, i think its all of
them because it taps too fast to be just 1.
I dont think there is anything worn out in the engine as it only had
22k on it when i started. everything certianly looks brand new.
I replaced everything inside and got the crank ground.. I used
plastiguage an everything and it was all perfect. I used a good
torque wrench on everything inside and I took a lot of care making
sure all the pistons, rods and caps were all the right way.
I thought that if my cam timing was off a tooth it could be valves
hitting the pistons, but I dont THINK it is.. I did align the marks,
but I'm starting to second guess myself looking for the culprit.

I played with the timing a lot and it made absolutely no difference.
I thought about the CPS hitting the flywheel thing, the bellhousing
is from advanced adapters(to an nv4500), but it has been just like
that for years with no problems.
the engine builder that did all the machine work for the engine wants
to take a look at it monday... I'll keep y'all posted.
again, thanks for the efforts.

theres nothing i hate worse than building engines.. i really enjoy setting up gears and axles, i love fabricating... this thing better run for 60 years...

 

I don't have any answer for you Chris, but with the luck you've had in the last month............don't stand too close to me.

Keep us posted on what you find out. I'm interested in knowing what the heck it is.