Returning after a long time.

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fp55scca
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Re: Returning after a long time.

Post by fp55scca » Sat Feb 03, 2018 6:38 am

--Byas, the "visual" on the intake looks better, but there is no telling condition/performance without measuring the cam circle, lift and duration, etc. We can probably search those numbers stamped on the cams themselves, and the cast numbers on the camboxes to try to determine what you have installed, but for expediency and for the performance reasons I stated above, I would still plan to replace the cams in pairs.

--As an alternative, you could source a mild street cam, such as a 40/80 (and these come in a variety of lift and durations) and place that cam in the intake side, and move your intake cam to the exhaust (as long as you still plan to retain the block-mounted distributor).

--Note: Your fan arrangement is interesting. I can't tell from the photos exactly how it is driven?
Jim Scurria
Norfolk, VA

1972 Fiat 124 Spider
1971 Spider - SCCA FP-24
1974 Fiat 124 Spider
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Re: Returning after a long time.

Post by davedecker4 » Sat Feb 03, 2018 8:52 pm

Is that a 1438cc fan setup? Either from DOHC or the OHV. Also I think the 1438 DOHC used the centrifugal oil filter in front.
I would not recommend replacing the cams with stock 2L either. Most 1608 had more performance cams with a few different options available. Most 2l stock cams were much less aggressive with emissions in mind. You might do well to replace with a pair of 1600 performance cams. Also figure out if oil passage to that cam lobe is or was plugged.
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Re: Returning after a long time.

Post by bnam2 » Wed Feb 14, 2018 10:18 pm

Got a cam from Tony (thanks!). I plan to temporarily install this cam until I've figured out what's what on this engine. I met the original builder of the engine who tells me the head was ported and polished. But, he believed it was a 1600 head, while the casting says it's a 1800 - so possibly may have been switched at some point.

The carb is a 34 DCHD which was stock on the 1500. This is a new repro. It has a block mounted non-vac advance distributor. It is not clocked correctly with #4 spot on cap connected to #1 plug.

The fan is mounted directly on pulley without EM clutch. Perhaps I should change to an electric set up.

The bellhousing is missing the tins that cover the gaps, will need to make those.

So, my plan for now is:
1. Remove radiator (will see if I can convert it to having a coolant reservoir while I have it out)
2. Remove timing belt (I hope this 1608 block is late enough that it uses the spring tensioner and not require the spring balance to get the tension correct)
3. remove exhaust cam tower with engine still in car. And then replace exhaust cam. Reinstall
4. Replace in head thermostat while I am at it. (need to source this).

I've replaced the timing belts on my 80 and 81 Fiat spiders. I don't remember using any special tool to hold the cam wheels while installing belt. Any suggestions on how to do that? Anything I've missed?

Perhaps, I should look to fab up an electric fan mounting for radiator while I am at it and remove the existing fan.

I will continue to research various new cam options and also try to determine if I need a new head or not.

Btw, the original builder of the engine is an old time racer and builder and is the engine designer of the Team Mahindra Formula E car (which currently is in 2nd spot with 2 wins in 4 races). He still builds both gas and electric engines for a wide range of individual and corporate clients (Lotus has sent him their electric car for him to tweak). I could go to him to have the engine built out, but I think it doesn't make sense unless I upgrade brakes/chassis. I really just want it to be a nice cruise car that is easy to drive/maintain so not really looking to make it a high perf car.

Byas
Byas
1965 Fiat 1500 Cabriolet with 1600twin-cam
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fp55scca
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Re: Returning after a long time.

Post by fp55scca » Thu Feb 15, 2018 11:33 am

bnam2 wrote:
Wed Feb 14, 2018 10:18 pm
......It has a block mounted non-vac advance distributor. It is not clocked correctly with #4 spot on cap connected to #1 plug.

.....The fan is mounted directly on pulley without EM clutch. Perhaps I should change to an electric set up.

.....The bellhousing is missing the tins that cover the gaps, will need to make those.

.....1. Remove radiator (will see if I can convert it to having a coolant reservoir while I have it out)

.....4. Replace in head thermostat while I am at it. (need to source this).

.....I've replaced the timing belts on my 80 and 81 Fiat spiders. I don't remember using any special tool to hold the cam wheels while installing belt. Any suggestions on how to do that? Anything I've missed?
-------------------------------------------------------------

--Correct timing for your distributor will be #4 contact on the cap, connected to #4 plug, with the engine in top dead center (TDC) and cam timing set correctly, and #4 cylinder in the firing position (both valves closed).

--I wouldn't worry too much about the radiator and fan for now, as long as it's cooling properly? Aside from a new radiator, the only advantage of an electric fan would be a slight HP savings while cruising.

--The engine to bellhousing spacer, also serves as a spacer for the starter motor. These should be relatively easy to come by used.
The lower flywheel inspection cover is just a dust/rock shield, but should also be readily available used.

--The in-head T-stat for a TC motor is a 54mm stat, common to many GMC/Chevy motors. 185 degree would be fine.

--When replacing the timing belt in the car, I find it easy to turn the engine to TDC, place the car in gear with emergency brake on. I then use a simple tool manufactured from a piece of angle iron, bolted to the bellhousing after the inspection plate is removed. Slip in a straight slot screw driver to egage the flywheel and the engine will remain steady during belt installation.
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Jim Scurria
Norfolk, VA

1972 Fiat 124 Spider
1971 Spider - SCCA FP-24
1974 Fiat 124 Spider
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rridge
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Re: Returning after a long time.

Post by rridge » Thu Feb 15, 2018 1:48 pm

A confusing point in sorting what fits what Fiat Twin Cam is that there are two 1.6liter engines with many differences. The 1608cc engine is a growth version of the 1438 and first saw service in the Fiat 125. The 1592cc engine is related to the later 1756cc and 1995cc engine. The 1608 and 1592 overlapped in production about 1973. The 1592 was used in 131 and 132 sedans in Europe. Both 1.6L engines were used in versions of the 124 chassis that reached the U.S.

Another confusing point is that the easy to read number on a head is the casting numbers. The part number of a head depends on how the casting has been machined. Some 1756 and 1995cc engines have heads with the same casting numbers but different chamber volumes and valve pocket details.
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'81 Turbo Spider
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bnam2
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Re: Returning after a long time.

Post by bnam2 » Thu Feb 15, 2018 8:34 pm

Jim,
Thanks for info and the tip on the tool. The gearbox I have is a 1500 5-speed. I assumed that the inspection covers will be different from a later 124 box.

Richard,
The block I have is a 1608 from a 125.

Byas
Byas
1965 Fiat 1500 Cabriolet with 1600twin-cam
!971 VW 1302LS Convertible in original condition
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