Returning after a long time.

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bnam2
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Re: Returning after a long time.

Post by bnam2 » Tue Jan 30, 2018 9:53 pm

Brad,
I agree.

My last question was not about my block or head. But, whether my observation -- that if head and block were flush aligned at the rear it must be a 1608 or 1438 blocks - as the 1592/1756/1995 blocks were a tad longer than the head -- was true. If so, it may help in the future if other marks were erased as is the case with my block.

BYas
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Re: Returning after a long time.

Post by fp55scca » Tue Jan 30, 2018 11:33 pm

bnam2 wrote:
Tue Jan 30, 2018 9:53 pm
My last question was not about my block or head. But, whether my observation -- that if head and block were flush aligned at the rear it must be a 1608 or 1438 blocks - as the 1592/1756/1995 blocks were a tad longer than the head -- was true.
------------------------------------------
--Byas, I just checked a 1608 engine with 1608 head installed and can report that the head actually overhangs the engine block, on both the front and the rear, by a few mm.

--As Brad said, we've pretty much established that you have a 1608 block. The exact origin of your head is still somewhat in question. Tomorrow I'll post a side by side comparison of the water port of a 1608 and a 1756 head. You are correct, that a 1756 head (and 1592 and 2L) can be installed directly on a 1608 block, but not a 1608 head on any of the 132 series motors, without modification.
Jim Scurria
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1972 Fiat 124 Spider
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Re: Returning after a long time.

Post by fp55scca » Wed Jan 31, 2018 5:59 pm

--Sorry Byas, I forgot to get the photos of the water ports of the 1608/1756 heads today while there was still daylight. (I have the heads stored in a shed.) I'll try again tomorrow.
Jim Scurria
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1972 Fiat 124 Spider
1971 Spider - SCCA FP-24
1974 Fiat 124 Spider
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ramzi
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Re: Returning after a long time.

Post by ramzi » Wed Jan 31, 2018 6:45 pm

1438, 1608 and 1592 blocks are not as long as 1756 and 1995.

Although the cylinder any head will bolt on to any block, as Jim notes, the water passages are different on the 1438 and 1608 head than the later ones.

1756 and 1995 blocks are the same length, but the 1995 is a few mm taller.

Fiat never changed the alignment of the combustion chambers on the cyl head. By that all 1438 combustion chambers align with all 1438 cylinder bores, while they do not on a 1995. The combustion chambers on a 1995 head are in the same location as a 1438.

There's some boring information for you ya
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Re: Returning after a long time.

Post by bnam2 » Wed Jan 31, 2018 8:29 pm

Ramzi,
I've read that the 1438 an 1608 are the same length and 1592, 1756 an 1995 are longer (but same length as each other - though the 1995 is taller). Fiat kept the heads the same size. So in the last 3 blocks, the cylinder heads are not all centered the same way.

This was the basis of my conclusion that you should be able to ID the last 3 blocks if the blocks are longer than the head at the rear.

Byas
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Re: Returning after a long time.

Post by ramzi » Wed Jan 31, 2018 8:40 pm

So this gives one pause for thought. As you move the cyl head combustion chamber off-center, you reduce efficiency. Imagine the potential performance that could have been gained with 1995cc motors that had centered combustion chambers. That said, I cant imagine Fiat never tried it..
Ramzi
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1939 Fiat 508CM (Military)
1939 Fiat 508C (Civilian)
1966 Fiat 500F
1967 Fiat 500F
1966 124 Sedan RHD (Oldest in N. America)
1972 124 Spider 2.0L
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2018 Alfa Romeo Stelvio Ti
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Re: Returning after a long time.

Post by fp55scca » Thu Feb 01, 2018 11:01 am

--Right you are Ramzi, and as you know, this issue presents a real challenge when trying to fit high-dome HC pistons, particularly for extreme race applications. Some racers have now adopted offset-dome designs for the #1 and #4 pistons, vice relieving the head on those pistons, as has typically been done in the past.
Jim Scurria
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Re: Returning after a long time.

Post by fp55scca » Thu Feb 01, 2018 11:19 am

--Got a few photos this morning that should help clarify the water jacket vs. head water port issue for the 1608 and 1756cc engines.

--In the first photo, note the larger water port in the 1608 head in the top of the photo:
1608-1756 Water Port.jpg
1608-1756 Water Port.jpg (95.44 KiB) Viewed 385 times
--On the block, 1756 on top and 1608cc on bottom. Note, more free space on the 1608.
1608-1756 block water-gallery.jpg
1608-1756 block water-gallery.jpg (83.55 KiB) Viewed 385 times
--Just a quick visual for block length. 1756cc on bottom is about 6mm longer than the 1608 on top:
1608 block vs. 1756.jpg
1608 block vs. 1756.jpg (82.45 KiB) Viewed 385 times
Jim Scurria
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Re: Returning after a long time.

Post by cgranju » Thu Feb 01, 2018 11:49 am

Ok, so,this all brings up a tangential question I once thought i knew the answer to regarding our lego/garanimals engines....how will a 1592 head mate to a 1995 block? (can I ask that here, or will I be banished for thread deviation?) Seems like I recall hearing that Pierre had done this & the 124 Coupe circle track racer that once lived in ATL (surfaces periodically on facebook) had at one point been described as having that combo.
Chris Granju
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bnam2
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Re: Returning after a long time.

Post by bnam2 » Thu Feb 01, 2018 12:15 pm

fp55scca wrote:
Thu Feb 01, 2018 11:19 am

1608-1756 Water Port.jpg

--On the block, 1756 on top and 1608cc on bottom. Note, more free space on the 1608.

1608-1756 block water-gallery.jpg

/quote]

Jim,
Thanks for the pics!!

Apart from the larger hole on the 1608 head, I noticed a few other things.

The holes in the 1608 and 1756 head don't always match in location. For instance, the 1756 has a small gallery to the left of that front central gallery, while the 1608 does not have one there, but a bit further to the back and left.

The difference in size of those 2 front central galleries seems irrelevant when both feed the same sized much smaller hole on both blocks. But the difference in location of a water gallery may be the more relevant factor. So, if a 1756 head was used on a 1608 there is at least one gallery in the head and one gallery in the block that are not connected to each other.

The shapes of the galleries in some case are also different between the blocks -- like those on the left and right of the 1st cylinder are slightly different between the 2 blocks.

A 1756 head gasket laid on a 1608 block or vice versa could be a telling story.

Byas
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!971 VW 1302LS Convertible in original condition
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