1800cc Head - Issue or not?

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t00nces
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1800cc Head - Issue or not?

Postby t00nces » Sat Dec 16, 2017 2:15 pm

Greetings,

I've been working on restoring my 1981 FI 2L and part of that process includes a new head, higher compressions pistons, the whole 9 yards. I order a port/polished head with bigger valves from one of the well know suppliers and when I turned it over to start measuring valve lift, I noticed a bunch of pitting at the base of the head - #2 and #3 cylinders.

My question is, will this make a difference in performance and/or is this normal for a remanufactured performance head? I think of the engine as a giant air pump so I'm wondering if deformations in the head affect efficiency due to different air/fuel swirl patterns. I'm pretty sure the profile and 'smoothness' of the intake has a large effect but I don't know about where the head mates to the gasket and block.

Any thoughts and advice appreciated.

Regards,

t.

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Nut124
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Your car is a: 1978 124 Spider 1800

Re: 1800cc Head - Issue or not?

Postby Nut124 » Sat Dec 16, 2017 4:50 pm

Your picture link did not work.

Did you ask the seller about it? What surface is the pitting at? Any pitting where the fire rings seal would be a problem. The same with the oil supply. Near the edge of the gasket needs to be smooth too. If it is in the water galleries, maybe not.

Edit: I see your picture now; Lay the gasket on it and see if the pits line up with the fire rings.

Besides sealing, the rough spots can result in detonation due to "hot spots" and carbon buildup. Some builders buff and polish the chambers for this reason. I would not like a head like that. Will they take it back?

Note that an 1800 head will likely add another 0.5 points of compression vs a 2L head. More if it has been milled heavily.

Nut124

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riverdadd
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Re: 1800cc Head - Issue or not?

Postby riverdadd » Sat Dec 16, 2017 6:57 pm

im no expert, but if it was mine. i would start over.... with the vendor

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dinghyguy
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Re: 1800cc Head - Issue or not?

Postby dinghyguy » Sat Dec 16, 2017 11:23 pm

my $.02 worth is I would return it and try again, the combustion chamber should be genrally smooth. and the pits at the edge seem to me to an invitation for leakage. I would not use it and even if I had to pay the shipping I would try again.

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t00nces
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Re: 1800cc Head - Issue or not?

Postby t00nces » Sun Dec 17, 2017 10:53 am

Thanks for all the advice. I didn't think it looked very good but I didn't want to initiate a return without getting some advice. I don't want to name the vendor yet either in order to give them the chance to make it right. Mistakes happen and perhaps this one just flew off the shelf without much oversight.

Cheers and Happy Holidays.

t.

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RRoller123
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Re: 1800cc Head - Issue or not?

Postby RRoller123 » Sun Dec 17, 2017 12:32 pm

Did you send in a head to be modified, or just purchased an entire unit?
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BEEK
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Re: 1800cc Head - Issue or not?

Postby BEEK » Sun Dec 17, 2017 6:37 pm

That head has swallowed something into a cylinder or 2, bounced it around and probably spat it out. In theory the head will work just fine. The issue is the areas are potential hot spots and are obviously not smooth. I would reject that head and ask for another or my money back. Now on the other hand, If that was my head and on a normal engine with no performance mods. I might bolt it on and go down the road. Provided i was not paying for that head. One could also smooth out the rough spots, maybe weld them up and grind them back. But that would be extensive work for a readily available head
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t00nces
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Re: 1800cc Head - Issue or not?

Postby t00nces » Mon Dec 18, 2017 10:29 am

It was purchased as a 'performance head' direct from the vendor and is going on a full rebuild with 10.3:1 Ross pistons, etc. etc. I'm hoping that they will ship me a new head and I can simply ship them the original one they sent. If push comes to shove, I can have my original 2L head done here in YYC and start over but I'll be out significant $$ since the one I purchased came from the U.S. and when you add exchange, shipping and customs it gets even more depressing ;)

Regards,

dt

Nut124
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Your car is a: 1978 124 Spider 1800

Re: 1800cc Head - Issue or not?

Postby Nut124 » Mon Dec 18, 2017 3:01 pm

t00nces wrote:It was purchased as a 'performance head' direct from the vendor and is going on a full rebuild with 10.3:1 Ross pistons, etc. etc. I'm hoping that they will ship me a new head and I can simply ship them the original one they sent. If push comes to shove, I can have my original 2L head done here in YYC and start over but I'll be out significant $$ since the one I purchased came from the U.S. and when you add exchange, shipping and customs it gets even more depressing ;)

Regards,

dt


YYC? Calgary?

Where do you get the Ross pistons?

If you want to consider keeping the head, get the gasket, position it on the head and use a marker to draw the fire ring circles on the head. If any of the gouges are under the fire rings, it's certainly junk. If not, one could try to smooth out the spots with a grinder w/o damaging the sealing surface.

Nut124

t00nces
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Your car is a: 1981 Fiat Spider 2000 EFI

Re: 1800cc Head - Issue or not?

Postby t00nces » Tue Dec 19, 2017 10:27 am

Yes, I'm in Calgary, where winter is about to take hold..... :wink:

I've spoken with the guys at D&W who are doing the bottom end for me and it looks like one of the pits does cross the fire ring. I'm still working with the vendor and will update the thread once things get sorted.

The Ross pistons came via Allison's Automotive. Mark has been very helpful with advice and has provided a number of the parts for the rebuild.

Regards,

t.


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