1438 Performance Builds

The forum for all of your technical questions on your classic FIAT autos
User avatar
bartigue
seimila club
Posts: 6440
Joined: Sat Jan 23, 2016 11:49 pm
Last Name: Artigue
First Name: Bradley
Contact:

1438 Performance Builds

Post by bartigue » Fri Nov 08, 2019 4:42 pm

Curious to know the specification for 1438 performance builds, if anyone has done one. I know that the first rally Spiders (pre-CSA) were tuned 1400s, I have no specification for them other than a notation that these were "series produced" engines e.g. they tuned the hell out of them. The photo I've seen of a 1970 rally car has twin Webers at least...presumably 40 or 44s.

Pistons? Cams? Thoughts?

Thanks

B
-----------------------------------------------------------
Brad Artigue
1969, 1969, 1970, 1979, 1980, 1981, 1982, and 1982 124 Spiders
1969, 1970 850 Spiders
77 X1/9
http://fiat.artigue.com
User avatar
rridge
tremila club
Posts: 3682
Joined: Sun Jan 24, 2016 9:18 pm
Last Name: ridge
First Name: richard

Re: 1438 Performance Builds

Post by rridge » Fri Nov 08, 2019 6:16 pm

Pierre had some good suggestions in this thread in response to a question from Lee Putman:

https://www.mirafiori.com/forum/viewtop ... h+stephens
Richard
'81 Turbo Spider
Rockville, MD
User avatar
bartigue
seimila club
Posts: 6440
Joined: Sat Jan 23, 2016 11:49 pm
Last Name: Artigue
First Name: Bradley
Contact:

Re: 1438 Performance Builds

Post by bartigue » Fri Nov 08, 2019 7:38 pm

Decent back and forth but fairly obvious from that thread that only one or two people actually owned the motor and did the work. Too much speculation in there.

So if someone has done things beyond the "put in a pertronix" - pistons, cams, etc., I'd like to hear it. The only 1438 I ever tuned up was with 80.4 9.8:1 pistons and 35/75 cams and a 32/36 DFEV and it ran really nice. Keep in mind that 1438cc motors had the second largest stock carburetor ever installed on any Spider engine, at least in Europe, the 34DFH (the largest was the 28/36 DHSA2 on the 1608), it can take a lot of carb provided the air velocity can be kept high.

Well all that and I have a set of 44IDFs I want to install on it. Ever hear of tiny venturis?
-----------------------------------------------------------
Brad Artigue
1969, 1969, 1970, 1979, 1980, 1981, 1982, and 1982 124 Spiders
1969, 1970 850 Spiders
77 X1/9
http://fiat.artigue.com
User avatar
fiat850
quattromila club
Posts: 4213
Joined: Sun Jan 24, 2016 11:30 am
Last Name:

Re: 1438 Performance Builds

Post by fiat850 » Sat Nov 09, 2019 3:40 am

bartigue wrote:
Fri Nov 08, 2019 7:38 pm
Keep in mind that 1438cc motors had the second largest stock carburetor ever installed on any Spider engine, at least in Europe, the 34DFH (the largest was the 28/36 DHSA2 on the 1608), it can take a lot of carb provided the air velocity can be kept high.
Also of note would be the 34DMSA used on the '74 124 Spider. ;)
---------------------------------------------------
Jeff Stich
User avatar
bartigue
seimila club
Posts: 6440
Joined: Sat Jan 23, 2016 11:49 pm
Last Name: Artigue
First Name: Bradley
Contact:

Re: 1438 Performance Builds

Post by bartigue » Sat Nov 09, 2019 6:51 am

fiat850 wrote:
Sat Nov 09, 2019 3:40 am
bartigue wrote:
Fri Nov 08, 2019 7:38 pm
Keep in mind that 1438cc motors had the second largest stock carburetor ever installed on any Spider engine, at least in Europe, the 34DFH (the largest was the 28/36 DHSA2 on the 1608), it can take a lot of carb provided the air velocity can be kept high.
Also of note would be the 34DMSA used on the '74 124 Spider. ;)
Correct, 34DFH and 34DMS are the same basic carburetor. One has a pneumatic secondary (DFH), one has a mechanical one (DMS). DMSA has several emissions related components the european counterparts (and the DFEV, which is essentially the same carburetor as well) lack.
-----------------------------------------------------------
Brad Artigue
1969, 1969, 1970, 1979, 1980, 1981, 1982, and 1982 124 Spiders
1969, 1970 850 Spiders
77 X1/9
http://fiat.artigue.com
User avatar
friedman
mille club
Posts: 1946
Joined: Wed Aug 24, 2016 8:13 am
Last Name:

Re: 1438 Performance Builds

Post by friedman » Sat Nov 09, 2019 8:05 am

Are you looking to build a historically correct rally motor or just trying to extract more power for street use?
Carl in Virginia
75 spider
83 Bertone
User avatar
bartigue
seimila club
Posts: 6440
Joined: Sat Jan 23, 2016 11:49 pm
Last Name: Artigue
First Name: Bradley
Contact:

Re: 1438 Performance Builds

Post by bartigue » Sat Nov 09, 2019 8:58 am

More power

True rally spec is useless on a car that will mostly be on the street - too much cam/carb etc

In this case it likely boils down to pistons, mild cams, and a electronic ignition, and a single big carb
-----------------------------------------------------------
Brad Artigue
1969, 1969, 1970, 1979, 1980, 1981, 1982, and 1982 124 Spiders
1969, 1970 850 Spiders
77 X1/9
http://fiat.artigue.com
User avatar
miker
quattromila club
Posts: 4193
Joined: Sun Jan 24, 2016 7:55 pm
Last Name: Richmond
First Name: Mike

Re: 1438 Performance Builds

Post by miker » Sun Nov 10, 2019 1:32 am

Brad... are you looking at the Pertonix, Marelli electronic or one of the new 123ignition units?
MikeR (mirafiori.com since 1995)


1977 Fiat 124 Spider
Previously owned:
2012 Fiat 500 Prima Edizione #236 (now owned by my son David)
'86 Bertone X1/9
'81 Fiat Spider 2000 #236
'78 Fiat 131 four door
'76 Fiat 128 4 door
'74 Fiat 128 4 door
User avatar
bartigue
seimila club
Posts: 6440
Joined: Sat Jan 23, 2016 11:49 pm
Last Name: Artigue
First Name: Bradley
Contact:

Re: 1438 Performance Builds

Post by bartigue » Sun Nov 10, 2019 7:52 am

Probably pertronix as it has to fit under the manifold. The block Plex sits too close the timing belt for my big fat hands.
-----------------------------------------------------------
Brad Artigue
1969, 1969, 1970, 1979, 1980, 1981, 1982, and 1982 124 Spiders
1969, 1970 850 Spiders
77 X1/9
http://fiat.artigue.com
User avatar
SimcaBertone66
Posts: 688
Joined: Fri Oct 07, 2016 3:28 pm
Last Name: DeGasperis
First Name: Joseph

Re: 1438 Performance Builds

Post by SimcaBertone66 » Sun Nov 10, 2019 12:59 pm

It took me a long time to formulate what my point would be … as it relates to the question posed….. time machine here... imaging a brand new, never run, off the assembly line, 1438 TC, from a about to be shipped Spider …. .. perhaps to the USA …. pull it out and take it apart..... have the "racing department" engine team reassemble it , without changing a single part, to way higher standard, match every part, one to another, cc the combustion chambers , 3 angle valve job, optimum valve setting/adjustment, slave over setting up the crankshaft, we use to call it "blueprinting" every part, and a dynamically balanced rotating assembly, including clutch/flywheel … … I think that would constitute a "performance build" without including increased compression from pistons, hotter cam, larger carburetor and more powerful ignition system …
Joe DeGasperis
Post Reply

Who is online

Users browsing this forum: No registered users and 62 guests