2L block and 1800 head

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TulsaSpider
Posts: 1547
Joined: Tue Apr 29, 2008 7:33 pm
Your car is a: 1978 Spyder 124 2L
Location: Tulsa, Ok

2L block and 1800 head

Post by TulsaSpider »

So I pulled the 2L out of the parts car yesterday. From everything I read the 2L block and 1800 head is the way to go. My budget is slim but I wanted to start planning the swap. I really want some improved performance so I have a few questions I have only replaced the head gasket on my engine before. I know the head rebuild will be crucial and I have not rebuilt one before. Are there different types/designs of valves to use? I am guessing most of my $ will be spent on the head. I can always upgrade the carb later... maybe it's time for a third job? Between that and raising my daughter on my own I wouldn't have time to drive it then!
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Who knows what the compression ratio will be for this setup?
I hear the swap is pretty straight forward, here are some of my assumptions, please let me know if I am off base!
Use the 2L flywheel. I plan on lightening it some.
The blocks are the same length, meaning no modification to the driveshaft is necessary.
Use the cam wheels for the 1800, the timing belt from the 2000.
I plan on swapping out the crossmember.
What am I missing?
Pulling out the motor and trans was pretty easy though I had to drop part of the suspension which I didn't see coming.
Who likes my engine hoist?
Any words of wisdom would be appreciated! Especially from those who have done the same things.




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1978 Spyder 1800 make that 2L! Finally making real progress!
narfire
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Joined: Sat Dec 27, 2008 2:14 am
Your car is a: 1980 124 spider
Location: Naramata B.C.

Re: 2L block and 1800 head

Post by narfire »

Limited budget... great thing to do for a little more zip. I have done it on my FI and like the results.
I just had a 1800 head re-done and it cost me $425 cdn including surfacing, seals and valves ground, bead-blasted head and cam towers. Use this as a referance as I'm sure the price varies. The head gasket is the same and yes use the 2L belt.
The lightened flywheel is a good thing to do in my opinion as well.
Are you building a second engine while still driving your car? if so then more time as $$ become available is a good thing. I'd change the bearings,seals, piston rings ect on the block over that time as well. You can do that your self. I trust you have a manual, they do help,especially referencing the proper torques. Shimming the valves is something you can do your self as well, that valve tool makes thing easy,but I think some here have fabricated their own. Once all completed,you would have a nice engine with the knowledge all the parts are new and hopefully would not have any issues for some time.
Just my thoughts.. good luck
Chris
80 FI spider
72 work in progress
2017 Golf R ( APR Stg. 1)
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Ernie
Posts: 113
Joined: Wed Mar 19, 2008 2:07 pm
Your car is a: 1978 Fiat Spider
Location: Huntsville, AL

Re: 2L block and 1800 head

Post by Ernie »

TulsaSpider,

There shouldn't be any need to swap cross-members if you're installing the 2L into an 1800 car.

Good luck with the re-do.

Ernie
BEEK
Posts: 1833
Joined: Wed Mar 24, 2010 10:45 pm
Your car is a: 1975 Spider
Location: clermont fl

Re: 2L block and 1800 head

Post by BEEK »

if you do not swap the crossmembers you will need to shim up the motor mounts, as the oil pan is deaper, and it will rub the crossmember. but a few shims is much easyer to do and the 1800 crossmember is stronger in my opinion as well. if you are going into the bottom end, i would use stock 1800 pistons if you have them as well, the ones with the smaller flycuts. only if you have them available from your other motor. yes it will be an interference motor then, but keep the timing belt changed and it will be no issue. the valve sizes are the same from one to the other. compression should be about 9.5 to 1
Automotive Service Technology Instructor (34 year Fiat mechanic)
75 spider
, 6 Lancia Scorpions, 2018 Abarth Spider, 500X wifes, 500L 3 82 Zagatos. 82 spider 34k original miles, 83 pininfarina, 8 fiat spider parts cars
son has 78 spider
spiderrey
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Your car is a: 70 124 spider-74x19-03 ranger edge
Location: San Dimas, Ca

Re: 2L block and 1800 head

Post by spiderrey »

I always hear this, Ive done two 2 liter swaps into a 70 and 71 with no crossmember issues to date. I always install new motor mounts. Although, at the moment I have been considering swapping crossmembers to get a little more room under the hood for the 44 webers. But for now the car just sits as life gets in the way again. Need to finished building the shed and then run a gas and exhaust line for the new dryer.
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TulsaSpider
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Joined: Tue Apr 29, 2008 7:33 pm
Your car is a: 1978 Spyder 124 2L
Location: Tulsa, Ok

Re: 2L block and 1800 head

Post by TulsaSpider »

Yes I will be building this as a 2nd motor. I plan to put new bearings and rings and have the assembly balanced. Don't have any kind of time frame. So would you explain a little more about re-using the 1800 pistons?
On the crossmember, well not swapping would save some time and effort, always in short supply :) But how much do they need to be shimmed?
1978 Spyder 1800 make that 2L! Finally making real progress!
BEEK
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Joined: Wed Mar 24, 2010 10:45 pm
Your car is a: 1975 Spider
Location: clermont fl

Re: 2L block and 1800 head

Post by BEEK »

the 1800 pistons from a 74-77 motor have smaller valve reliefs, thus making more compression, if you have the funds i would recomend a set of high compression pistons. but the benifits of the 1800 pistons alone are worth it, especialy if you already have them.
crossmember, yes with new motor mounts clearance is not an issue, but its real close, as they wear you will have a rubbing between the oil pan and the crossmember. its only like 3/8 or 1/2 inch difference in the mounting pads. i have many times just put 2000 motors in 1800 and earlyer cars with no immediate fitment issues. but i would hate to tell someone that everything is fine and they have a sagged motor mount and the pan gets a hole rubbed into it. just a thought , your thoughts may very, please keep arms and hands inside at all times. :mrgreen:
Automotive Service Technology Instructor (34 year Fiat mechanic)
75 spider
, 6 Lancia Scorpions, 2018 Abarth Spider, 500X wifes, 500L 3 82 Zagatos. 82 spider 34k original miles, 83 pininfarina, 8 fiat spider parts cars
son has 78 spider
BEEK
Posts: 1833
Joined: Wed Mar 24, 2010 10:45 pm
Your car is a: 1975 Spider
Location: clermont fl

Re: 2L block and 1800 head

Post by BEEK »

isnt that a john deer motor hoist? :mrgreen:
Automotive Service Technology Instructor (34 year Fiat mechanic)
75 spider
, 6 Lancia Scorpions, 2018 Abarth Spider, 500X wifes, 500L 3 82 Zagatos. 82 spider 34k original miles, 83 pininfarina, 8 fiat spider parts cars
son has 78 spider
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TulsaSpider
Posts: 1547
Joined: Tue Apr 29, 2008 7:33 pm
Your car is a: 1978 Spyder 124 2L
Location: Tulsa, Ok

Re: 2L block and 1800 head

Post by TulsaSpider »

Ok Beek, you said "the 1800 pistons from a 74-77 motor have smaller valve reliefs, thus making more compression"
Mine is a 78... 1800 are they different?
Yes that's a John Deere hoist! I recommend them!Especially if your parts car is surrounded by 6' of weeds!
1978 Spyder 1800 make that 2L! Finally making real progress!
BEEK
Posts: 1833
Joined: Wed Mar 24, 2010 10:45 pm
Your car is a: 1975 Spider
Location: clermont fl

Re: 2L block and 1800 head

Post by BEEK »

78 could go either way
Automotive Service Technology Instructor (34 year Fiat mechanic)
75 spider
, 6 Lancia Scorpions, 2018 Abarth Spider, 500X wifes, 500L 3 82 Zagatos. 82 spider 34k original miles, 83 pininfarina, 8 fiat spider parts cars
son has 78 spider
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manoa matt
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Your car is a: 1978 Fiat 124 Spider 1800
Location: Honolulu, Hawaii

Re: 2L block and 1800 head

Post by manoa matt »

Beek,

From following others similar engine builds over the years I've collected the following numbers regarding the heads and ratios.

1800 head combustion chamber: 49cc
2000 head combustion chamber: 52cc

Stock compression ratio for 1.8 and 2.0 engines: 8.1:1

1.8 head with 2.0 block compression ratio: 8.6:1

1.8 head, 2.0 block, and 1.8 small relief pistons: 8.7:1


The head block combination raises the compression ratio .5, which is noticeable. While swaping the interference pistons only nets a .1 increase, probably not noticeable except on a dyno. The .1 increase might not be worth the trouble of fitting the pistons and also having an interference engine. More bang for the buck would be to get a thin head gasket and surface the head and block to raise the compression ratio to about 9:1, of course then you might need adjustable cam pullies. But for the same price of a thin head gasket, machine work, and adjustable pullies, you could just buy 9.8:1 pistons for $399 and be done with it.
BEEK
Posts: 1833
Joined: Wed Mar 24, 2010 10:45 pm
Your car is a: 1975 Spider
Location: clermont fl

Re: 2L block and 1800 head

Post by BEEK »

the compression numbers i gave were determined with a whistler. not a buret. so thats where i get my information
Automotive Service Technology Instructor (34 year Fiat mechanic)
75 spider
, 6 Lancia Scorpions, 2018 Abarth Spider, 500X wifes, 500L 3 82 Zagatos. 82 spider 34k original miles, 83 pininfarina, 8 fiat spider parts cars
son has 78 spider
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TulsaSpider
Posts: 1547
Joined: Tue Apr 29, 2008 7:33 pm
Your car is a: 1978 Spyder 124 2L
Location: Tulsa, Ok

Re: 2L block and 1800 head

Post by TulsaSpider »

So with the HC pistons an 1800 heads what kind of gas would I have to be getting?
I would like to hear from folks who have done the swap. To see just what kind of difference we are talking here. I just went to look at a 67 Mustang a friend of mine is getting for $4000 and it's a California- very little rust car.... what a steal! anyways... I may be able to strong arm him into letting me use some space in his garage.. not sure
1978 Spyder 1800 make that 2L! Finally making real progress!
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