This thread is up to track my progress on my Duke build. Its the first major rebuild that I have ever done and I have the assistance of a former mechanic. This so far has been fun and unique with the way somethings have had to be done. I'm up for advice, tips, questions, and general feedback. A few of you have seen my other thread "Beefing up the Duke. Regarding what is being done to the Duke is as follows:
Complete Overhaul Bore .020 over Against all advice but had no choice (machine shop said so) Shaved Head Three-Angle Valve Job Hyperutectic Pistons Moly Rings Performance Cam w/ springs Aluminum Timing Gear Set Custom Exhaust w/ Flowmaster 80 dual outlet
WOW thats well umm interesting.. but also.. in GOOD way.. teaching.. teaching others that if all else fails ..find some trees and if you dont have the tools.. I like it. so what are you doin to the engine. as far as build wise?
Holy crap on a stick! I don't believe I've ever seen it done that way, but more power to ya. Best thing I could recommend on the rebuild is cleanliness. Engines may get dirty on the outside, but they like being clean on the inside. Especially after being freshly rebuilt. If you have a die grinder or something similar, grind all of the excess flashing off of the block and head. That'll make the engine look a little better and eliminate the flesh rippers of the future. One thing I did to cosmetically dress up the engine too was to put a bolt in the holes on the cylinder head that usually don't get any. Keeps the junk from getting in there again. I think there were two or three on my '84 that I had to find bolt/plugs for. Mechanically, when you go to torque down your main caps and head bolts, dip the threads in a little oil first. That'll make sure you get a good true torque reading.
------------------ Whade' "The Duck Formerly Known As Wade" Duck '87 GT Auto '88 Ferrario '84 Indy
[This message has been edited by whadeduck (edited 11-11-2007).]
Our major concern was safety! If something did not strike us as safe, it wasn't done. This was done as per the Pontiac service manual... minus the hydraulic lift.
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05:09 PM
Mr.PBody Member
Posts: 3172 From: Cincinnati, Ohio, USA Registered: Oct 2006
..... and I just want to stick with my stock crank
87+ 2.5 crank is better and is 100% bolt-in. That's what I used in my 85 Iron Duke rebuild. So far it has lived over 5K rpm several times. I am looking into a harmonic balancer too, but thats a story for another time.
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05:50 PM
Mr.PBody Member
Posts: 3172 From: Cincinnati, Ohio, USA Registered: Oct 2006
Has anyone ever tried the 1.8 BBC roller rockers before? And what could be expected when using those? I've got a million things I want to do with what I got, and redoing a non-balancer Duke was something I was rolling around in my head, so, watching these threads has been a bit of a priority for me.
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12:18 PM
pswayne Member
Posts: 1282 From: Lawrenceville, GA USA Registered: Sep 2006
The 88 crank has that big old gear on it for driving the balance shaft/oil pump thing. I don't know if that particular crank would fit in an earlier duke. But if it did, that gear would serve as more re-enforcing, making the crank just a bit stronger than an 87.
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05:36 PM
KurtAKX Member
Posts: 4008 From: West Bloomfield, MI Registered: Feb 2002
So I am at my biggest hold up right now: Everything is at the machine shop. I know that the block is finished but that is the only thing finished. Crank, pistons, rods, cam, timing set, and head are all in. I hope to have most of it out in one paycheck, but I have to get it as I can pay for it .
Picked up the block today, Machinist said it wasnt far from having to be bored .030. Cylinder 2 was pretty banged up from the piston top cracking apart. I called the other shop for an update on the head... He says it was warped bad but still repairable and had it taken care of.
Pep boys/ autozone / meijer sell this flex pipe for like $11.99 I was going to use it to make that S bend but ended up using it for my test pipe. I can try to find the box later this evening when I get back to my house.
i don't want insane compression, i would like this engine to last, the only reason it was bored and shaved so much is because it is what was required to have the head and block back to running condition. The machinist said that the compression would not change that much from the shaving of the head. ???????
You have to be careful when milling the 2.5's head. I had one milled .020 in order to raise the comperssion, after this I had a lifter tick that was very difficult to get rid of since the 2.5 doesn't have adjustable rocker arms. I wound up puting washers in between the rocker arm bolt the the head in order to get rid ot the noise.
When the head is milled (a lot such as in my case) the pushrod wind up being two long, this is what made it necessary to space up the rocker arms.
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08:59 PM
Mr.PBody Member
Posts: 3172 From: Cincinnati, Ohio, USA Registered: Oct 2006
Yes custom pushrods GM use to have different size pushrods ,,do not know if they are still available.. there are longer available not certain about shorter,, the bores should be cleaned out with a clean rag with a light oil on it the machining and honing processleaves trash in the bore the machine shop will clean it ,but I always found material from the hone on the rag,, you scrub it with the oily rag,I also clean the valve seats but this is not so important..Use a piston to push the rings into the bore so you can gap the rings.check each cylinder at 3 different places,check the gap at each level then bring to spec,, mark the piston and place the 1 rings on the 1 piston that goes into the 1 cylinder hole,, the ring should be perfectly level when you check gap..if you do not have or can not rent a ring compressor.you can get sheet metal from home depot and make one..if you do not have a ring expander, do not install rings on all pistons at once the rings will dig into your fingers,and if you do them all at one time!you are more likely to break one.. If you go to the expense of a rebuild use new head bolts,you can use the old head bolts placed in the block holes B P blaster the bolts let set and twist to clean out threads, if not taped out by machine shop so you have no binding when you torque down head in at least 3 stages,use a beam torque wrench not a clicker.if the slightest doubt, replace oil pump..Eyeball valve stems to make sure they are all equal,make sure locating pins are in block,install pistons as they will run ,,avoid any movement to align rods to crank
Thank you for your support!! since I can no longer drink ,I encourage heavy drinking in others..Many think my post are wierd .. I pack much more information in my post than most,,takes to long to use proper english .. all people seem normal ,,untill you get to know them
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08:21 PM
PFF
System Bot
Nov 25th, 2007
1MohrFiero Member
Posts: 4363 From: Paducah, Ky Registered: Apr 2003
Nice job. Very interesting pictures. Don't forget the obiligatory standing-in-the-engine-bay picture. Saxman started a new thread for these pictures in the General topic area the other day.
I live out in the back woods also but still use a hydraulic lift and motorcycle lift to drop cradles. Your method looks to be very cost effective but when rain is in the forecast for the week, you might not get much done!!!
------------------ 87GT 3.4 Turbo- 0-60 5.2 seconds 2006 3800SC Series III swap in progress Engine Controls, PCM goodies, re-programming & odd electronics stuff " I'M ON THE LOOSE WITHOUT THE JUICE "
So everything is out of the machine shop and being put back together. The block and head have been painted chevy orange and the air cleaner assembly, valve cover, and oil pan will be getting a fresh coat of black. Most thing are going smoothly... STILL NO HOSES!!!!
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12:43 AM
PerKr Member
Posts: 641 From: Mariestad, Sweden Registered: Nov 2006
do you have any pictures of your progress? this is interesting (especially considering that there are so few serious duke build threads), but would be more interesting with some pics
Last weekend it was the guts, today it was the rest of the assembly. The only thing left to do is to swap the water pump pulley and drop the car on to the assembly
Best thing I could recommend on the rebuild is cleanliness. Engines may get dirty on the outside, but they like being clean on the inside. Especially after being freshly rebuilt. If you have a die grinder or something similar, grind all of the excess flashing off of the block and head. That'll make the engine look a little better and eliminate the flesh rippers of the future. One thing I did to cosmetically dress up the engine too was to put a bolt in the holes on the cylinder head that usually don't get any. Keeps the junk from getting in there again. I think there were two or three on my '84 that I had to find bolt/plugs for. Mechanically, when you go to torque down your main caps and head bolts, dip the threads in a little oil first. That'll make sure you get a good true torque reading. 
