swapping pistons and rods from one duke to another (Page 2/2)
Daytonaspeed24 AUG 12, 12:17 PM

quote
Originally posted by olejoedad:

If your 'Fiero mechanic' thought the distributor was out 180°, simply changing the plug wires around won't solve that problem.

The distributor needs to be removed and reinstalled after rotating the crank one turn.

Pull #1 plug, rotate the engine bring #1 piston up to TDC on compression stroke, look at the distributor flag. Is it pointing at the #1 plug wire?

If the 'Fiero mechanic' advised you to get another engine, I would question his advice.



lol 8 times I did that and it only started when i swapped the wires around i was questioning if the diagram was correct for number one wire on the cap .
Daytonaspeed24 AUG 12, 12:29 PM

quote
Originally posted by Patrick:

You have a rebuilt engine that won't run, possibly due to the cam gear being out one tooth... and you want to tear the engine apart and transfer the pistons and rods into an old engine?

Honestly, I'm not trying to be nasty... but this makes absolutely no sense.

As long as the pistons and cylinders are the same size (one or the other not over-sized)... sure, you can swap them over. That's based on the assumption that those pistons have zero hours on them. The rods can be swapped as well, as long as the rod bearings match the size of the crankpin journals.

However, I think you need a competent mechanic to have a look at the situation before you do anything further.

Where are you located in Alberta? There might be a forum member local to you who could help set you straight.

Thanks for the feedback. ive completely lost confidence in my car even when I got my motor back it took so long i didnt trust it was done right. one thing he said was most of the Gaskets didnt work. so here I am 3 years later and having issues. I should have just stuck with can you check and clean and hone the block then he could have told me what pistons and rings to get.

the reason i said what I did is the fella who was looking at it said there was a 84 in the pull yard w 176k for me that would be a refresh candidate. i suppose I absolutley jumped the gun with out opening mine up. but if something was wrong with mine but the pistons and rods were fine can i change them into another one. thats the ultimate question and I doubt he did any head work by the clinking and clanking going on when it was running for its few minutes





olejoedad AUG 12, 01:05 PM

quote
Originally posted by Daytonaspeed24:


lol 8 times I did that and it only started when i swapped the wires around i was questioning if the diagram was correct for number one wire on the cap .



I've reread all of your postings in this thread and did no see where that was your question.

We are more than willing to help if we have good information.

Follow my advice for retiming the engine.
Tell us what diagram and where you got it.

Give us good info and we will be able to help you.

The year of your Fiero would be good to know as well, not all Fiero Dukes are the same...

[This message has been edited by olejoedad (edited 08-12-2023).]

82-T/A [At Work] AUG 12, 01:23 PM

quote
Originally posted by Daytonaspeed24:
I WAS TOLD TO FIND ANOTHER ENGINE ALL I WANT TO KNOW IS IF I CAN PUT MY PISTON AND RODS INTO THE OTHER ENGINE IF I NEED TO AND IF THEY ARENT DESTROYED OF COURSE. TRUST IN OTHERS WHO TOUCH MY CAR IS AT A LOW point right now and im tired of wasting time so here I am trying to get information from the people who know these. But while we are talking cam timing thats what this fella said is the most probable issue ( I wouldnt know) would that damage the cam.




Short answer is YES. But there's a bit more to it.

I've never rebuilt a Duke before, but I have some other engines... I'm going to be redoing a Duke in a few months, so I'll know more then.

Basically, the things you want to consider is:

- Balance of the complete rotating assembly: Each piston and rod assembly needs to be weighted separately, and ideally all balanced to within an acceptable error percentage from one to another. This is not the hard part, and can be done at home either with a file, or whatever to remove material from one piston to another to ensure that (assembled with rings, etc.) they all match. But the next part is ensuring that the crank is balanced. You will want to make sure the crank is properly balanced before you put the piston assemblies on.

- Bearing Sizes: Make sure that you identify the correct bearing sizes for each of the connecting rods. There's standard, and then increased sizes.

- Piston Sizes: There's what's called "overbore," and people often do this to get additional horsepower (more displacement). Make sure that the pistons you're putting in are the correct size, and not larger (won't fit) or smaller (horrible compression).

Beyond that, everything should be good to go assuming the engines both have similar wear. I'd recommend you hone the cyl walls (regardless) so that the rings will properly seat.


- BREAK -

I'm really interested to see what you're dealing with on the cam timing. Any chance you can take a picture for me? I've not rebuilt a Duke before, but from what I understand, it should be pretty self-explanitory... if I'm not mistaken, there is a little dot on both the cam and crank gear... and also as far as I know, the crank and cam gears can only go on ONE way. I do know that some people advance timing by skipping a tooth... so maybe he did that? It's supposed to give better performance but... who knows.
Daytonaspeed24 OCT 13, 05:56 PM

quote
Originally posted by Daytonaspeed24:

question for those who know. i had my engine rebuilt a few years ago and i finally got it into the car and she doesnt want to run properly so being at my wits end ( cursed car ) I had a mechanic who works on Fieros come look at it. after thinking I was 180 out he changed the wires same problem he switched them back the identical thing was happening which is strange. what he is thinking the engine guy put the cam gear out one tooth.
so whatever I am piseed i provided all the parts skirted pistons, moly rings, moly bearings new cam bearings ect. I havent opened up the engine yet to see if I can find the Problem. but I think i was ripped off . The engine guy said half of my gasket kit didnt work ( red flag) I should have opened it up to see if my parts were in there .
ok now for my question
CAN i SWAP PISTONS AND RODS FROM ONE DUKE TO ANOTHER or are the rods matched with the crankshaft. I know whatever the size of bore ill need new rings or have a real machine shop hone for the size of rings. i think im 20 over?? i cant remember but he told me what to order.
if the bore is ok on the other block i can change the rings and bearings if they are standard.
I just cant seem to find any info on using pistons and rods from one block to another
hope this makes sense
THANKS
theogre OCT 13, 11:48 PM
"swapping pistons and rods from one duke to another"

If you didn't bore to require "0.030" etc oversize pistons... Technically Yes but old Piston Rings likely will hate you & not seal. Old pistons can wear in odd ways too cause own set of problems. This Is 100% wrong thing to do fixing why can't turn engine by hand.
82-T/A [At Work] OCT 14, 08:18 AM
Is this question coming up because you are asking if you can swap the pistons and rods from your 87 block to your 84 block?

If they're both standard size, then you're going to end up with the same problem. They sell all these parts on Rock Auto for really, really cheap. I just got a set of Sealed Power pistons... a set, for $43 dollars. They were less than $10 a piece (and then add tax).


With all the money you're spending on buying different things, my opinion is that you may just be better off buying a short-block from Rock Auto or somewhere else and calling it a day...
Dennis LaGrua OCT 14, 09:51 AM
I believe that if your engine is not running correctly you need to get down to basics. Have you done a compression or cylinder leakdown test? Do you have spark, and proper fuel pressure?
Any noticeable knock sounds? Done a scan of the ECM?
It is unlikely that pistons and rods on a low mileage rebuild are the problem.

------------------
" THE BLACK PARALYZER" -87GT 3800SC Series III engine, custom ZZP /Frozen Boost Intercooler setup, 3.4" Pulley, Northstar TB, LS1 MAF, 3" Spintech/Hedman Exhaust, P-log Manifold, Autolite 104's, MSD wires, Custom CAI, 4T65eHD w. custom axles, Champion Radiator, S10 Brake Booster, HP Tuners VCM Suite.
"THE COLUSSUS"
87GT - ALL OUT 3.4L Turbocharged engine, Garrett Hybrid Turbo, MSD ign., modified TH125H
" ON THE LOOSE WITHOUT THE JUICE "