My 4.6 Project engine
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Re: My 4.6 Project engine
Thanks guys. Boy I'm I glad I found this site. Diamond pistons it is. I was able to start porting my head today. I'll post pictures tomorrow
- SilverXJ
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Re: My 4.6 Project engine
Taking that little off the deck won't effects its structural rigidity.. there is a lot to the block. Yes, its long but its also quite tall.jsawduste wrote: The other side is the structural integrity of the block itself after taking that much metal off. Failing head gaskets are not uncommon as the block is quite long by comparison which makes it susceptible to warpage.
The Icon 944 & 945 are forged 4032 pistons, not hyper.Last I looked 944`s were going for about 550 plus pins and this is for a simple hyper piston.
2000 XJ. 4.6L stroker
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Re: My 4.6 Project engine
Agreed. Shoot, I took .054 off my block to get a quench of .035 and there was still tons of meat left. I have over 2500 HARD miles on this engine already and no issues yet. Even had a (dissapointing) over heating issue on one wheelin trip, no issues.SilverXJ wrote:Taking that little off the deck won't effects its structural rigidity.. there is a lot to the block. Yes, its long but its also quite tall.
As far as high compression ratios, I am running about 8.96 DYNAMIC and dont have any pinging issues... even on regular grade gas.
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Re: My 4.6 Project engine
Good luck !!
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Re: My 4.6 Project engine
Sorry, I have not looked at this thread in a week. I have been busy porting my head. I am glad that I started with an old 258 head that I dont plan to use because my technique was not great on my first go around. On my first head I simply gasket matched, I am attempting to do a more accurate port match on my final head.6TIME wrote:Yes you will have to setup any motor you are building to measure where zero deck will be. After the block is cleaned up and bored to the new piston size you can slide them in and measure with a depth mic. Be aware that there are sometimes variances in rod lengths from resizing and/or factory tolerances, and possibly slight variations in crank throws... so don't assume they are all the same length.. Measure so you know exactly how much you can take from the deck. If you plan on running 10:1 I'd highly recommend running a tight .038-.045 total quench height. But, with it that high and with an iron head... you'll still be flirting with potential ping issues when hot and under load w/ pump gas. Why not play it safe and keep it in the low/mid 9's?akadeutsch wrote:Question. I imagine pre-assembly is required to get a zero deck height. I am shooting for a CR of 10:1. Will I be able to achieve this without a zero deck
No, not with a stroker setup. Most strokers need dished pistons to compensate for the increased volume from the added stroke.akadeutsch wrote: Will I need domed pistons?
What will this motor be used for?
I plan to use this Jeep for weekend fun. I drive a Volvo to work everyday so really this will be used for trail riding and camping...expedition type stuff. I would also like to add that I must have been smoking crack when I said that I wanted a 10:1 C/R. That is too high. I do want to run premium gas though so I think a 9.5:1 C/R will be best with this old iron head. Also I will only be taking .010 off the deck. The more that I read the more that I see that anything over 9.5/1 just causes problems. Thanks for all the help. This thing is really starting to come together. One of these day I will figure out how to post pictures
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Re: My 4.6 Project engine
Tonight I said to hell with all of the practice work and dove in to my real 0331 head. I was able to polish one combustion chamber and start on the valve guide in the exhaust port. what do you all think? I have read every thread on head porting a half a dozen times and i am anxious to hear where you think I should go next. I started with the C/C because my stones are still sharp and I need the point for the fine work around the spark plug relief.
I will hopefully finish at least one whole port tomorrow night. I don't plan to take any more than I have to from the exhaust port...just a polish. I will trace the intake to the head and attempt to do an accurate port match for the intake side. And finish it with 40 grit rolls. I am using a pneumatic die grinder regulated down to about 10-12,000 rpms at full throttle. The die grinder was 9.95 at harbor freight and it came with a pretty nice set of stones. i am also using the standard abrasives porting kit along with a carbide bit that i found in the bottom of my tool box.

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Re: My 4.6 Project engine
Here is a picture of where I'm at right now with the head. Ive started bowl work on my first exhaust port. All that I am doing here is removing the valve guide bump and casting lines and then polishing. I remove any ridges that I can feel with my finger as well. If I can't feel it I leave it alone. What is shown here was done with a grinding stone turning at roughly 10,000 rpms. I dont want to change any geometry here, correct? 

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Re: My 4.6 Project engine
I was able to finish one whole cylinder tonight. here is a couple pictures. Tell me what you think.
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Re: My 4.6 Project engine
More progress. I was talking with my machinist the other day and I think I'll be installing new seats and bronze guides...at least new exhaust seats.
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Re: My 4.6 Project engine
At this point my work in the combustion chamber is about done. I have relieved the valves as much as possible using the old head gasket as my guide, removed the edge that the seat cutter makes when it bores out the seats, and polished each of the C/Cs with cross buffs and pb blast for lube. I still have three intake and three exhaust holes to clean up. I am just waiting to get some new long shank grinding stones in the mail.
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Re: My 4.6 Project engine
my precious, so round , so shiny…. hehe - I don't know a hole lot about head polishing but by golly that shit sure is shiny. 

95 Silver ZJ 4x4 4.0L (soon to be stroked/boosted) currently DD
1999 Victory V92 (first year production) street bike/cruiser
95 ZJ Turbo Boosted Stroker build threadhttp://www.jeepstrokers.com/forum/viewt ... f=8&t=4342
1999 Victory V92 (first year production) street bike/cruiser
95 ZJ Turbo Boosted Stroker build threadhttp://www.jeepstrokers.com/forum/viewt ... f=8&t=4342
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Re: My 4.6 Project engine
I must say that I am impressed with the results of my first ever attempt at an accurate port match.
I have only done the intake ports so far as I don't yet have my exhaust manifold. And I have heard here that there is not much work to do if any on the exhaust ports anyhow. So here is how I did it.
I started by going to ACE hardware and picking up a sheet of 28 gauge aluminum that is big enough to trace the entire plenum gasket onto. Once I had my sheet I cut it to size with tin snips and then used a hammer on a cement floor to pound it straight again as the tin snips tend to warp the finish. First I marked and cut the holes to attach my piece of aluminum to my intake manifold. Then found bolts with the appropriate shoulder width to support my new aluminum "plenum gasket" to my intake manifold with no play to speak of. I then drilled a hole in the middle of the manifold ports beginning to open them up for sizing. Then I used a carbide cutting bit to open the holes that I drilled in the ports to the EXACT size of the actual intake manifold ports. Use care here as your carbide bit will not hesitate to cut through your aluminum intake manifold. When all of your new "plenum gasket" ports are opened to the size of the manifold port you have what looks like and exact copy of your plenum gasket made out of 28 gauge aluminum. Now place this new aluminum "gasket" onto your head. It should fit very exactly over the guide pins on your head. You will see areas that dont exactly line up. Scribe those areas onto your head and then remove the thing you made. Now remove material from your head out to the scribe lines that you just made. Then place the aluminum gasket back on the head. This time, remove more of the aluminum gasket to
EXACTLY
match the port interface on your head. Now, take the aluminum gasket off of the head and put in back on the intake manifold. This time it will not line up. Scribe the new outline of the head transition onto the intake manifold and remove your aluminum gasket. Remove material from your intake manifold out to the lines that you just scribed and you are done. Now, mount the intake to the head and stick your finger up the C/C and into the intake ports and feel the transition. The 1/8 inch step that used to be there is now a smooth transition and you only took away as much material as was necessary. After I was done with this I also camfered the port transitions ever so slightly and I think this helped with the alignment 

I started by going to ACE hardware and picking up a sheet of 28 gauge aluminum that is big enough to trace the entire plenum gasket onto. Once I had my sheet I cut it to size with tin snips and then used a hammer on a cement floor to pound it straight again as the tin snips tend to warp the finish. First I marked and cut the holes to attach my piece of aluminum to my intake manifold. Then found bolts with the appropriate shoulder width to support my new aluminum "plenum gasket" to my intake manifold with no play to speak of. I then drilled a hole in the middle of the manifold ports beginning to open them up for sizing. Then I used a carbide cutting bit to open the holes that I drilled in the ports to the EXACT size of the actual intake manifold ports. Use care here as your carbide bit will not hesitate to cut through your aluminum intake manifold. When all of your new "plenum gasket" ports are opened to the size of the manifold port you have what looks like and exact copy of your plenum gasket made out of 28 gauge aluminum. Now place this new aluminum "gasket" onto your head. It should fit very exactly over the guide pins on your head. You will see areas that dont exactly line up. Scribe those areas onto your head and then remove the thing you made. Now remove material from your head out to the scribe lines that you just made. Then place the aluminum gasket back on the head. This time, remove more of the aluminum gasket to



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Re: My 4.6 Project engine
Here is a couple pictures of the head right before I brought it to the mech shop. They will clean it all up and install new seats...I was not careful enough around the old seats so I have no choice here. 12 bucks a hole. 144 plus the seats and they are including a 3 angler valve job. They will also flatten the matting surfaces and install my new comp cams springs and stock rockers. I asked if they thought that I needed new valve guides and they said no. So I dont think that I'll get new guides. When I get it back it should be ready to mount to my short block.
which brings me to my next delema. what to do about pistons. I know we have gone over this but I have yet to pull the trigger and circumstances have changed. I like the geometry of the KB 945. But the 945 piston is forged and that comes with a pretty high price tag. I do not plan to run 20 psi of boost on this thing and I highly doubt she will ever put down even 300 HP. So why do I need forged pistons? I would be happier with a good hyper piston I think. Does anyone make a hypereutectic piston with the same geometry as the KB 945? The KB Tech said they did not make a cast mold that was the same as the 945. In other words they do not make a hyper piston that resembles the 945 forged. I guess I'll read the FAQ again.
which brings me to my next delema. what to do about pistons. I know we have gone over this but I have yet to pull the trigger and circumstances have changed. I like the geometry of the KB 945. But the 945 piston is forged and that comes with a pretty high price tag. I do not plan to run 20 psi of boost on this thing and I highly doubt she will ever put down even 300 HP. So why do I need forged pistons? I would be happier with a good hyper piston I think. Does anyone make a hypereutectic piston with the same geometry as the KB 945? The KB Tech said they did not make a cast mold that was the same as the 945. In other words they do not make a hyper piston that resembles the 945 forged. I guess I'll read the FAQ again.
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Re: My 4.6 Project engine
I think I will just pay the price for the IC 945s and buy the last set of pistons this thing will ever need...I hope. I like that they offer different dish options between the 944 23cc i think and the 945 is 10.5cc. It allows for a lot of tuning to the C/R. Which is important because i removed some material from the C/C when I polished and CC'd them.
Both my head and block are at the shop and i am bored. I have started replacing ground straps on the chassis with heavier gauge copper wire. But I have basically run out of work to do. How do you guys feel about massaging the Crank shaft? Just removal of the casting lines?

Both my head and block are at the shop and i am bored. I have started replacing ground straps on the chassis with heavier gauge copper wire. But I have basically run out of work to do. How do you guys feel about massaging the Crank shaft? Just removal of the casting lines?

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Re: My 4.6 Project engine
Correction, I will be buying the 944's. I have been reading and reading about C/R and I think I want to stay in the low 9s, high 8s.
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