Big valve source?

I got mine several years ago from Rockauto for about $6 each. Try searching 1995 FIAT TIPO 1.6L L4.
 
Thanks for the replies

I tried getting creative with rock auto searches, found the 39.5mm intakes, but the same listing (1995 Tipo) shows exhaust valves which are 31mm. 1.8L Tipo shows exh. Valve dia. of 36.1mm, but 3mm too short, and I'm not sure of keeper design. There is a second listing for the 1.6L exhaust valves, but no specs. Did you guys get all 8 valves? Part numbers? One of our vendors sells big valve heads, but not valves, and another sells only intakes. Is it wise to instal 39.5mm intakes and retain stock (33mm) exhaust valves? I've got a regrind 236 cam and headers.
 
Last edited:
Tipo 1600 is 39.5 intake and 31.5 exhaust ... simply use 1500 x19 / strada exhaust valves (33.4)

Some other sohc (punto GT for example) exhaust valves have three groove retainer collets and a shorter stem.

Don't shop on price, buy quality. Valves vary considerably in material and construction. i.e magnetic /non magnetic, one or two piece construction (friction welded head and stems of different materials sometimes) surface finishes (chrome plated stems or stellite seating faces) as just a few examples....besides the cost of the valve is minimal, the cost of the oversized seats and having them correctly installed and then correctly cut is far more expensive.

39.5/33.4 is my preferred combination...for a carburetted car... but for an efi engine with stock manifolding the 39.5'sare a bit of a waste of time...as the stock manifolding will be the flow limiter and the flow potential of the 39.5 intake will be unused...you want a high port air speed. IMO your better off with a 37/37.5mm intake valve in this situation.



SteveC
 
Larger seats

Opening up the original seats to suit bigger valves will make them too thin and weak and prone to falling out of the head.

Probably not the answer you wanted.

Rob
 
Big valve source

So I feel I should conclude this thread. This is my first Fiat, I bought it not running and sitting without an intake for a year plus. Rust sitting on the valves necessitated removing the head. Short story short I had the block honed and decked, new bearings and rings. Then MWB had 20% off sale and I ended up with a regrind cam and headers. Next step is bigger valves, right? With thanks to this wonderful network, I searched rock auto UK to find 40 mm intake valves for like fifty bucks delivered. I read a PBS article stating that these motors show little benefit of larger exh. valves, and I noted that 1300 and 1500 have same intake valves, (so 1500 already has enlarged exh.) So, I went with 40 mm intakes and stock exhausts on my FI 1500. And yes, larger seats are necessary but are generic.
Now, should I start another thread for my questions on flatslide Keihins?:shock2:
 
Mike said:
I read a PBS article stating that these motors show little benefit of larger exh. valves
Click to expand...

And they were wrong/incorrect/masking the fact that larger exhaust valves weren't really available in those days. That article is very old.

These engines can indeed benefit from bigger exhaust valves.

Cheers,

Rob
 
Big valve source

rjplenter said:
And they were wrong/incorrect/masking the fact that larger exhaust valves weren't really available in those days. That article is very old.

These engines can indeed benefit from bigger exhaust valves.

Cheers,

Rob
Click to expand...

Please then do answer my original question of where to buy larger exhaust valve for 1500 SOHC Rob
 
Re: Valve size sets

Mike said:
I tried getting creative with rock auto searches, found the 39.5mm intakes, but the same listing (1995 Tipo) shows exhaust valves which are 31mm. 1.8L Tipo shows exh. Valve dia. of 36.1mm, but 3mm too short, and I'm not sure of keeper design. There is a second listing for the 1.6L exhaust valves, but no specs. Did you guys get all 8 valves? Part numbers? One of our vendors sells big valve heads, but not valves, and another sells only intakes. Is it wise to instal 39.5mm intakes and retain stock (33mm) exhaust valves? I've got a regrind 236 cam and headers.
Click to expand...

The 1995 Fiat Tipo 1.6L L4 engine uses a 39.5mm intake valve, with an 8mm stem diameter & 108.5mm length. The 1995 Fiat Tipo 1.4L L4 engine uses a 37.5 intake valve, with the same stem diameter & length. Same car, 2 different engines. ;)

The 1990 Fiat Uno Turbo 1.4L also uses a 37.5mm x 8 x 108.5 intake valve, & the same year Uno Turbo 1.5L uses a 36mm x 8 x 108.5 intake.

All are available on the RockAuto site:

39.5mm intake:
http://www.rockauto.co.uk/catalog/x,carcode,190303,parttype,5544

37.5mm intake:
http://www.rockauto.co.uk/catalog/x,carcode,191693,parttype,5544
http://www.rockauto.co.uk/catalog/x,carcode,178581,parttype,5544

36mm intake:
http://www.rockauto.co.uk/catalog/x,carcode,918288,parttype,5544

Using the standard Fiat X1/9 1.5L 33mm x 8 x 108.5 Fiat P/N 5973129 exhaust valve will suit any of these intake sizes just fine. Good discussion by fiatfactory (Steve Cecchele) on valve sizes can be read here (scroll way down the page to "4b. Valve train upgrades"):

http://xwebforums.com/forum/index.php?threads/22546/

For oversized exhaust valves, he also writes:

"Another oversized intake / exhaust valve for Fiat SOHC use intake / exhaust valve from Peugeot / Citroen / Fiat Scudo, Ulysse 1584cc (diesel) engine.

intake ( 41.6 x 8 x 108.8 )
exhaust ( 34.5 x 8 x 108.37 ) chrome faced and stellite head."

I haven't personally taken the time to look that Scudo/Ulysse exhaust valve up on RockAuto, just tossing that info into the ring for ya. :grin:
 
Last edited by a moderator:
Actually all Uno T's use a 36mm intake valve, some use a three groove collet and some a single.

And that ebay seller has those listed as UnoT exhausts, but the Uno T exhaust is three groove collet retainer.... they all use 33.5 exhausts, but the valve is much higher quality material than the NA versions.

SteveC
 
A little birdie once told me that Nissan or "datson" valves were almost perfect for this swap... If memory serves it was from a 280. but Cant remember. Anyone hear of this?
 
Sorta...

jjay911 said:
A little birdie once told me that Nissan or "datson" valves were almost perfect for this swap... If memory serves it was from a 280. but Cant remember. Anyone hear of this?
Click to expand...

The Datsun/Nissan valve is what PBS modified to use on their BVH. Using the late-model Fiat valves as noted by others is a much better (cheaper/easier/less time-consuming) option nowadays. Unless one is rebuilding their PBS head to spec, also using the PBS cam, etc..
 
You must log in or register to reply here.
Back
Top