Are early 89-91 cylinder heads really that bad?

[bgilbert]

Are early non-intercooled 89-91 cylinder heads really as bad as everyone says they are? I've heard all about the bigger injector bores, cracks etc. I'm all set to have the head and block fireringed, and tapped/reamed for 14mm studs. Just wanting opinions on whether the head I have now is worth fire-ringing? A new style head runs about $800-900 when its all said and done/shipping etc. Piers no longer has the sale btw. Thats alot of money that could go towards something else. Thoughts?

 

[MMiller]

I have no experiance, but you have to wonder why cummins changed the design. They must have been having enough problems to change designs. Why take the risk and upgrade a head that in stock applications has cracking issues? You'll really kick yourself if you pay to have this head oringed/ported, then have the head fail, and then have to pay the money again for another head to be oringed and ported.



Its your money Bill, but on my 90 when I get to the point of needing headwork, I'll go with an upgraded head and be done with it.



Michael

 

[Greenleaf]

Yep. The school bus head I replace was an '89 engine. It was split open between the valves and elsewhere. ( cannot recall at this time where all the cracks were located. ) And this was a factory rated engine . Not some hot rod. I'd postpone untill you get the $$ for the new head.



You may opt to throw caution to the wind if you don't mind pulling the head. But then you (may) have to clean the coolant out of the crankcase and the oil outta the cooling system.

-S

 

[JLEONARD]

I agree... don't throw money into an old head design. They changed from 9 to 7mm holes to add material and solve a problem. It is solved. You're up in the area that will challenge the upgraded design let alone the old design.

Jay

 

[1stgen4evr]

"A new style head runs about $800-900 "



Shop around, I think you can beat that. .



James

 

[JDailey]

Bill-I wouldn't mess with that 9mm head. There is a place down in Evansville... I think it's called Tri-State cyl heads... I've alot of heads from them. New and used... pretty resonable on price.

 

[bgilbert]

Bill-I wouldn't mess with that 9mm head. There is a place down in Evansville... I think it's called Tri-State cyl heads... I've alot of heads from them. New and used... pretty resonable on price.

I forgot about them. Seems like someone posted a link to them or from ebay aways back, like $750 for new heads... I'll try searching.

Edit: found them. http://www.tristatecylinderhead.com/catalog/product_info.php?products_id=45. $799 free shipping. Looks like I'll give them a call asap.

 

[SGibson]

Is "fireringing" dieselspeak for o-ringing a block&head?

 

[MMiller]

I cannot explain it, as I don't really understand it, but oringing is different then fireringing. I understand that oring is a step up from stock, and then firering is another step up. Maybe one of the hi po guys that know will speak up.



Michael

 

[DPS]

Orings use a small diameter wire to add to the seal on a copper gasket, or the stainless ring on a factory gasket. Fire rings use a much larger diameter mild steel ring that is the combustion seal, and you use a modified factory gasket to seal the oil and water.



Josh www.dieselperformancesolutions.com

 

[SGibson]

O-ringing is a machined operation where you cut a trough around the periphery of the cyl. bore of the block or the chamber of the cyl. head and insert a wire ring like . 032 that would set in . 016 post flush,on a 331-392 Chrysler Hemi's that are blown for example this is a pre-requsite because they only have 4 bolts per cyl clamping the head to block it gives the gasket a chance under extreme cyl. pressures. 429Boss fords were O-ringed from the factory. Providing flow is the same or better I would use the later head.

 

[1stgen4evr]

Where do you get the 'rings'? I understand that they are just piano wire but how do you join the ends?



MIchael, I tried an email and got a failed message. Do you have a new email service?



James

 

[SGibson]

I couldn't tell you James, maybe from a company like childs&albert or donovan or keith black, one of the top shelf outfits that deals in block and or head hardware, You would only need 2 or 3 sizes to cover anything that ever came out of Detroit, I measured a 392 head@ 4. 3250 on a 4 inch bore or . 1625 from the edge. It could be butted or file fit if it had some pliability I guess. I pretty much use it as a sign of serious abuse on swap meet parts or something thats now obsolete ie "boxed rods". Bill I haven't tried to hijack your thread talking about gas motors, maybe one of you guys could explain what this "cm" means in all your sigs. Steve.

 

[MMiller]

I'd call Enterprise Engine, PDR, Schieds, they'd know where to get the wire. I saw somebody mentioned using welding wire, but don't use me as a source.



"cm" is the size exhaust housing on their turbos. 18 cm or 21 cm is stock, 16, 14, and 12 are all various upgrades.



James, you'll have a pm in a minute. My addy hasn't changed.



Wow, this thread got a little off kilter didn't it. :-laf



Michael

 

[SGibson]

Thanks Mike I still don't quite get it but we'll save it for an upcoming thread.

 

[bgilbert]

Well I took the plunge. Ordered one from TriState in Evansville. Original equipment casting from Brazil. I'll let yall know how it looks when it gets here. I'm not sure whether or not I'm gonna have the block fire-ringed and tapped for 14mm studs. I might just have the head done and then use 12mm studs.

 

[Greenleaf]

I purchased a new OEM head from NAPA. It twasn't that expensive, I thought. I'd simply use the 12 studs and possibly ring the head. Good to go.

 

[bgilbert]

Napa EEK!! Is this one on the 89 that still leaks :-laf ??

 

[Greenleaf]

Yep. But the head gasket is blown and THAT is a Cummins kit. It's blown on the front right corner and the left rear side.



It's tough to say where NAPA buys the heads. Probalbly Pur-Formance Diesel. That is where the marine nozzels came from.

 

[Mhannink]

ok so we now have an idea of orings what about fire rings what exactly is that