Finishing a hot 1800 build

Make it go fast! Kick it up a notch. Post tips in here.
justrhines
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Joined: Sun Jan 05, 2020 6:43 pm
Your car is a: 1975 Fiat Spider

Re: Finishing a hot 1800 build

Post by justrhines »

Nut,

When I did my build, I bought this intake off of eBay:

https://i.ebayimg.com/images/g/~b4AAOSw ... s-l400.jpg

It looks to be a Pierce Manifold with the center support cut out to make room for the linkage. As for the linkage setup, I used a standard arm and ball linkage off the throttle shaft, and made my own throttle cable support extending below the manifold. The cable pulls the throttle arm down, towards the ground. Most mount the cable above the cams, but I thought it looked cleaner this way (and it looks that you feel the same).

I did have to "port" the manifold a bit to make room for the 44's.
jon8christine
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Your car is a: 1976 Fiat 124 Spider
Location: Wyoming

Re: Finishing a hot 1800 build

Post by jon8christine »

So was going to the dual 44s a significant improvement in power over a single 32/36 etc. after doing the other engine work to take advantage of it?
Nut124
Posts: 748
Joined: Wed Oct 25, 2017 6:39 pm
Your car is a: 1978 124 Spider 1800

Re: Finishing a hot 1800 build

Post by Nut124 »

justrhines wrote:Nut,

When I did my build, I bought this intake off of eBay:

https://i.ebayimg.com/images/g/~b4AAOSw ... s-l400.jpg

It looks to be a Pierce Manifold with the center support cut out to make room for the linkage. As for the linkage setup, I used a standard arm and ball linkage off the throttle shaft, and made my own throttle cable support extending below the manifold. The cable pulls the throttle arm down, towards the ground. Most mount the cable above the cams, but I thought it looked cleaner this way (and it looks that you feel the same).

I did have to "port" the manifold a bit to make room for the 44's.
That is the same manifold I have. Mine came plain, no kit. Had to cut the middle and fabricate the center linkages from misc weber parts. In mine, the pull cable is under the manifold but level and pulling straight to the left. The carb cable jacket is attached to a bracket that mounts under the manifold onto the centermost carb studs. The cable jacket runs on top of the brake cylinder. I have a long return spring attached to the brake cylinder.

When seeking power from a stock engine, I would go in this order:
1. Header. Need to get rid of any stock exhaust with a single down pipe. This is required in order to tolerate any bigger cam with overlap. A factory exhaust with dual downpipes might be ok, not sure if these are common.
2. More cam. Properly timed in with adjustable pulleys. Not sure if bigger cam will do much with 8.0/1 SCR.
3. More compression, into the 9.5+ range but no more than 10.5.
4. More carb.
jon8christine
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Your car is a: 1976 Fiat 124 Spider
Location: Wyoming

Re: Finishing a hot 1800 build

Post by jon8christine »

Getting ready to start ordering parts after I drop off the block, crank and head at the machinist and he checks everything first. Help me understand why you went with an undersize aluminum crank pulley? That would just turn the alternator and water pump slower right?
Nut124
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Joined: Wed Oct 25, 2017 6:39 pm
Your car is a: 1978 124 Spider 1800

Re: Finishing a hot 1800 build

Post by Nut124 »

jon8christine wrote:Getting ready to start ordering parts after I drop off the block, crank and head at the machinist and he checks everything first. Help me understand why you went with an undersize aluminum crank pulley? That would just turn the alternator and water pump slower right?
Correct. No other reason. Cool looks perhaps. My car has a 4.30 rear end, the rpm is always up there. The Croft book states that stock water pumps have more than enough capacity.
jon8christine
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Re: Finishing a hot 1800 build

Post by jon8christine »

Did you have to relocate the alternator to the drivers side as the sellers mention with the aluminum crank wheel, or just buy a different belt? I'm not clear on why the alternator would have to be moved?
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RRoller123
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Your car is a: 1980 FI SPIDER 2000
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Re: Finishing a hot 1800 build

Post by RRoller123 »

The weight loss of the lightened crank wheel is significant over the big heavy cast iron one. Lower rotational power losses. I have one too, but I didn't notice that it has a smaller diameter, will have to take a look at that! My car now does not cool as quickly as before, but this was done at the same time as HC pistons were added, so I would expect it to run hotter. The fan of course comes on at the same time, but the car hardly gets down below 190 at all if left idling, i.e. there is no cycling, it just holds it at an acceptable level. Definitely something to look at. If I find it actually has a smaller diameter, I am putting the cast iron one back on.

Another side note: But a serious one. I found that the TDC mark is 4 degrees OFF on the aluminum crank pulley. This was done with a direct contact dial gauge, using probe extensions, on the top of piston #1, vertically through the spark plug hole, and was carefully verified repeatedly. I marked the correct TDC on the lightened crank wheel and used that. My TDC marker that is on the block is properly installed, is not bent nor otherwise damaged. I reported this to AR.
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Nut124
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Joined: Wed Oct 25, 2017 6:39 pm
Your car is a: 1978 124 Spider 1800

Re: Finishing a hot 1800 build

Post by Nut124 »

I would not expect any power gains from a lighter front pulley.

Regarding temp: You could try a lower setting thermostat and an aftermarket 175C radiator fan switch. I have both and mine idles at 175 on a hot day. I would not install one w/o the other.

Any crank TDC mark should be checked and corrected as part of a build. I installed a bracket on the front crank cover and marked it up with a new timing mark on the alu pulley. I find that the only reliable way to check TDC is with the piston stop method where the crank is rotated CW and CCW to a hard stop at an extended spark plug at about +/-30deg. TDC is half way between these stops.
jon8christine
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Your car is a: 1976 Fiat 124 Spider
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Re: Finishing a hot 1800 build

Post by jon8christine »

So did you have to move your alternator or buy a different size belt with the aluminum crank pulley? Vicks is telling me their aluminum pulley won't work on an 1800, only a 2L
Nut124
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Joined: Wed Oct 25, 2017 6:39 pm
Your car is a: 1978 124 Spider 1800

Re: Finishing a hot 1800 build

Post by Nut124 »

All I had to do was buy a slightly shorter belt.

There maybe two different 1800 engines with slightly different cranks. Mine has the late 2L bigger diam rear journal and the bigger flywheel bolts. Requires the late 2L bigger rear main seal. The front of the crank could be different from early 1800s as well.
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manoa matt
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Your car is a: 1978 Fiat 124 Spider 1800
Location: Honolulu, Hawaii

Re: Finishing a hot 1800 build

Post by manoa matt »

Mid year 1800cc spiders around 76 used a cast iron crank pully with only one belt groove, vs the later 78 1800cc that used the big heavy 3 groove pully.

I've had experts tell me otherwise, but my direct experience differs. You can fit a single groove stock cast iron pully from a 76 on a 2 liter block.
18Fiatsandcounting
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Your car is a: 1969 and 1971 124 spiders
Location: San Francisco Bay Area

Re: Finishing a hot 1800 build

Post by 18Fiatsandcounting »

One other option to consider is to have the ungainly 3 groove pulley turned down on a lathe to remove the grooves you don't need. I did this when I put a 2L block in my '69 spider, and my recollection is that block came from a 131 sedan which had air conditioning and other "stuff" running off that pulley. So I had a machine shop remove the front-most grooves, and it's worked fine since the late 1980s.

-Bryan
jon8christine
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Your car is a: 1976 Fiat 124 Spider
Location: Wyoming

Re: Finishing a hot 1800 build

Post by jon8christine »

Hmmm, guess I'm not sure which I have as the crank pulley has two grooves (alternator and AC pump I'm pretty sure), but never had a belt on the front grove. It weighs 3lb 6.5oz, The keyed shaft recess is 1.18" (30mm), OD is 5.8" and the crank shaft nut was a 1-1/2" socket.

The Auto Ricambi pulley looks the same as the Allison one and the AR page states it has a 30mm ID and fits '77-'85, guessing I got a late '76 that falls under the '77 category? Got an email out to him now asking why he and Mark both state the alternator needs to be on the left side (or moved there per Mark)...sorry if I'm hijacking your thread...I'll stop now :oops:

https://drive.google.com/file/d/182W7ar ... sp=sharing

https://drive.google.com/file/d/18AkgHA ... sp=sharing

https://drive.google.com/file/d/18B0jso ... sp=sharing

https://drive.google.com/file/d/18JYZ5W ... sp=sharing
18Fiatsandcounting
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Your car is a: 1969 and 1971 124 spiders
Location: San Francisco Bay Area

Re: Finishing a hot 1800 build

Post by 18Fiatsandcounting »

jon8christine wrote:The Auto Ricambi pulley looks the same as the Allison one and the AR page states it has a 30mm ID and fits '77-'85, guessing I got a late '76 that falls under the '77 category? Got an email out to him now asking why he and Mark both state the alternator needs to be on the left side (or moved there per Mark)
Let us know what you find out, as I'm curious too. On my 2L conversion, I kept things pretty much as original: alternator on the passenger side, distributor in the block, and even the original cylinder head. Everything seems to work, although the cooling system doesn't have a lot of margin, and I always assumed this was because the original radiator design doesn't quite have enough capacity. Doesn't overheat, but it can get close on really hot days stuck in traffic.

-Bryan
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phaetn
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Your car is a: 1974 Fiat Spider 1800
Location: Ottawa, ON Canada

Re: Finishing a hot 1800 build

Post by phaetn »

Heya gang. I'm really interested in this thread as I am about to embark on my own rebuild.

I have a 95a alternator upgrade mounted on the passenger side. It doesn't *quite* link up with the crank pulley so the belt is at a slight angle and I've once replaced the alternator pulley as it wore a ridge and started to slip. I was planning on having either the machine shop or my mech friend (who will do the majority of the rebuild) line it up by taking some meat off the alternator.

I have two questions:
1) I was wondering about using Vick's aluminum pulleys (I already have their adjustable cam pulleys) to make things look nice. I have a '74 1800 block with the appropriate stamp for the year of the car. Any caveats about aftermarket pulleys? Rrroller I'm concerned that you mentioned the TDC mark is off from the A/R one. Are the aluminum pulleys more likely to break compared to the old cast iron ones?

2) And, on the subject of colour-matching, I have stuff like the timing belt cover, the rad support, coolant outlet from head, dizzy plug on cam box (my ignition is on the block), and cam covers painted red with a high-temp paint, then clear-coated it. I am thinking about getting the metal bits powder coated. Does that make sense or is it just a waste of money and I should stick with the spray paint I did? It might be hard to match the timing belt cover (it can't get it powder coated, obviously, as the plastic would melt), but I might run without it if everything is new and fancy. :) As it is I cut an access panel into it so I can remove it without having to pull a red hose every time. Thoughts?
Image

Cheers,
phaetn
1974 CS1
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