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Iron duke head gasket blown head possibly toast what do i do next? by Fadingaway
Started on: 02-17-2014 04:05 PM
Replies: 10 (1831 views)
Last post by: Joseph Upson on 02-18-2014 11:59 AM
Fadingaway
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Report this Post02-17-2014 04:05 PM Click Here to See the Profile for FadingawayClick Here to Email FadingawaySend a Private Message to FadingawayEdit/Delete MessageReply w/QuoteDirect Link to This Post
I'm going to pull the head and replace the gasket, but I was wondering what I should do If my head is too far gone for reuse? I was thinking of an s-10 head swap I read somewhere that it has bigger valves? Anyone have some suggestions on what to do with my poor old duke?
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olejoedad
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Report this Post02-17-2014 05:33 PM Click Here to See the Profile for olejoedadClick Here to Email olejoedadSend a Private Message to olejoedadEdit/Delete MessageReply w/QuoteDirect Link to This Post
Fix it, swap it, or junk it.
GM used several different heads on the Duke, finding the correct mix of parts when using a different head from stock gets very interesting.
What year Fiero do you have?
When looking for a replacement head, use the head's cast-in Part Number and check with a local engine rebuild shop.
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Arns85GT
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Report this Post02-17-2014 05:42 PM Click Here to See the Profile for Arns85GTClick Here to Email Arns85GTSend a Private Message to Arns85GTEdit/Delete MessageReply w/QuoteDirect Link to This Post
Don't start spending money on the motor unless you are in it for keeps. The Iron Duke was ubiquitous and used in many different models.

If you look up the engine you will see all the cars it was used in. Normally you can get a replacement cheap. I'd pay $100 to $150 for one.

If you find a guy who did a swap, you can likely get it for shipping costs just so he can get rid of it.

If you are feeling like you'd like to keep the motor, the heads are easy to recondition. If the crank or cylinder is shot, this not an easy fix.

You need to know exactly what it broken before you decide.

On balance, it is easier to replace than to fix though.

Good luck with it.

Arn
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2002z28ssconv
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Report this Post02-17-2014 07:46 PM Click Here to See the Profile for 2002z28ssconvClick Here to visit 2002z28ssconv's HomePageSend a Private Message to 2002z28ssconvEdit/Delete MessageReply w/QuoteDirect Link to This Post
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uhlanstan
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Report this Post02-17-2014 07:58 PM Click Here to See the Profile for uhlanstanClick Here to Email uhlanstanSend a Private Message to uhlanstanEdit/Delete MessageReply w/QuoteDirect Link to This Post
The 84 to 86 4 duke will not accept the 91 to 93 G.M. dukehead
The 87 & 88 Fiero duke will accept the last model GM duke heads made. you need different pushrods & use apontiac grand Am intake manifold for best flow,, These heads will give you a power boost & better MPG.
the duke head will take some abuse,just check the head base mounting side with a straight edge
the late model duke has different looking ports do not mess with them but you can portmatch the head to the manifolds
it is more difficult but you can adapt the EMC & wiring from the later model car & get a HP boost the Duke needs
you can not gage the crank to rod play ,but you can turn th crank shaft over & as one of the piston travel downward >>Push down on it & if you feel slop ,, yo have a problem,try this on a couple of cylinders
the advantage of the Duke is 40 mpg highway & 26,28 around town & still fun to drive
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KurtAKX
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Report this Post02-17-2014 08:26 PM Click Here to See the Profile for KurtAKXSend a Private Message to KurtAKXEdit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by Fadingaway:

I'm going to pull the head and replace the gasket, but I was wondering what I should do If my head is too far gone for reuse? I was thinking of an s-10 head swap I read somewhere that it has bigger valves? Anyone have some suggestions on what to do with my poor old duke?


1) S10 head does not have bigger valves. If in doubt, look up the replacement intake and exhaust valves. You'll see the part numbers might be different, but that has to do with changes in the stem- read the head diameter.

2) what symptoms lead you to believe the head gasket is blown?

3) expect that you may have a broken head bolt on the exhaust side of the head.
Never do this Gasket job w/o new head bolts.
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Fadingaway
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Report this Post02-18-2014 02:03 AM Click Here to See the Profile for FadingawayClick Here to Email FadingawaySend a Private Message to FadingawayEdit/Delete MessageReply w/QuoteDirect Link to This Post
Its a 1984, I went to change the oil there ls loads of water in it. White smoke from the exhaust and overheating after bleeding the coolant system and the radiator fan on. Confirms the blown gasket. I don't have much money or really any at all and I need this thing on the road for as cheap as possible so I can get back to doing shade tree mechanic work to get by I'm going to pull the head and see what's going on, I know the bottom end is good but the top end makes all kinds of noise, a raspy rattle a squeak and some ticking so I think the head may be damaged
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Str8lineJKing
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Report this Post02-18-2014 06:01 AM Click Here to See the Profile for Str8lineJKingClick Here to Email Str8lineJKingSend a Private Message to Str8lineJKingEdit/Delete MessageReply w/QuoteDirect Link to This Post
Just chiming in here. The duke is not a quiet engine by any sense of the term. So there is always going to be alot of valve train noise. I myself am currently in the process of changing the head gasket and bolts on my 84. Going to get the head off today and hopefully there are no cracks. I replaced the head gasket a few months ago, but i did not replace the bolts and i think/hope that is the cause of my coolant to combustion leak. I however do not have "milky oil" so i dont think its leaking to oil. Just combustion. Therefore i pray 'tis just the head gasket.

------------------
1984 Pontiac Fiero SE Silver 2.5l 4-speed 4.10
1980 Chevrolet Citation Primered 2.5l Auto
1999 Kawasaki Drifter VN1500J Deep Gooseberry Purple
2005 Kawasaki Vulcan Classic VN800B Candy Red

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olejoedad
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Report this Post02-18-2014 07:03 AM Click Here to See the Profile for olejoedadClick Here to Email olejoedadSend a Private Message to olejoedadEdit/Delete MessageReply w/QuoteDirect Link to This Post
Inspect the head carefully or have it magnafluxed. Cracking is not uncommon.
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Str8lineJKing
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Report this Post02-18-2014 07:07 AM Click Here to See the Profile for Str8lineJKingClick Here to Email Str8lineJKingSend a Private Message to Str8lineJKingEdit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by olejoedad:

Inspect the head carefully or have it magnafluxed. Cracking is not uncommon.


Truth this man speaks! lol. I too will bead blast and magnaflux before reinstalling.
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Joseph Upson
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Report this Post02-18-2014 11:59 AM Click Here to See the Profile for Joseph UpsonClick Here to Email Joseph UpsonSend a Private Message to Joseph UpsonEdit/Delete MessageReply w/QuoteDirect Link to This Post
Unusual rattling noise at the top of the engine in this scenario may indicate a damaged piston/skirt from the oil film being washed away in the cylinder. So be sure to press on the sides of the piston perpendicular to the pin to look for a see-saw effect. You don't want to put a good cylinder head over a bad piston. You'll be able to tell right away if coolant entered the cylinder because the piston will be steam cleaned.
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