ArtsAutosBooksBusinessEducationEntertainmentFamilyFashionFoodGamesGenderHealthHolidaysHomeHubPagesPersonal FinancePetsPoliticsReligionSportsTechnologyTravel

The Chevrolet Cosworth Vega Engine with Weber Side Draft Carburetors

Updated on August 8, 2010
A restored Cosworth vega
A restored Cosworth vega
Webers with air cleaners
Webers with air cleaners
engine head
engine head
weber 42DCOE side draft carbs
weber 42DCOE side draft carbs
engine head
engine head

 When you paid around $6000 in 1975-76, for a Chevy Cosworth Vega, you could have bought a Corvette Stingray, or just about. The Cosworth Vega was the high end Vega, although it looked racy, it was not really the case. It had a computer to regulate the electronic fuel injectors, mag wheels, better interior. The engine was a twin overhead cam with 16 valves, so it was totally different than buying a non-Cosworth Vega, which was also a 4 cyl engine without a computer or fuel injection. Its engine was a 140 cu. inch, which generated around 90 hp. The Cosworth was 122 cu. in and generated 110 hp at 5600 RPM. In comparison, a 1967 Corvair Monza with two single carbs and six cyl generated 110 hp also. The Corvair Corsa of 1965-66, with four carbs produced 140 hp, its Turbo edition, 180 hp.

Because the Cosworth engine was totally different than the non-Cosworth vega engine, GM produced a totally different repair manual for it. For tune ups, the Cosworth noted these differences:

Compression: 170 psi

Plugs: AC R43LTSX with .060 gap

Timing: 12.0 deg BTC

Valve lash: .014

Idle speed: 1600 RPM

Fuel pump, in gas tank: 5.5 psi at 12.8 V; external pump: 6.6 psi at 13.5v

Air cleaner: A505C

Many Cosworths were modified using Weber Carbs, usually 2  two barrels, model 42 DCOE Side Draft or similar (the models ran from 38-45). The models in this class were similar. Weber carbs are more expensive and had to be synchronized (much like in the Corvair) so that all opened and closed at the same time and all had similar air flow. If this was not correct, the car would not run very well. The use of a Unisys for air flow still are available. The reason for changing to Webers, which remain fickle devices, is interesting. The standard Cosworth was fuel injected, no carburetors, controlled by a computer. As long as they worked, they were easy. Using Weber carbs meant no fuel injection, no computer needed.

If you have Webers on your Cosworth, the carbs may need adjustments and proper specs for the carb.


    0 of 8192 characters used
    Post Comment
    • profile image


      2 years ago

      Your horsepower ratings don't take into account the Cosworth rating is net horsepower, the Corvair's are gross ratings. The Corvair's engines also did not have to meet the much more stringent emissions standards. The 1975 Chevy Monza 265 CID V8 was also rated at 110HP.

    • profile image


      7 years ago

      Q: What is the expected hosepower with a well tunned

      Weber 42DCOE side draft carbs -- 2 x two barrels?


    This website uses cookies

    As a user in the EEA, your approval is needed on a few things. To provide a better website experience, uses cookies (and other similar technologies) and may collect, process, and share personal data. Please choose which areas of our service you consent to our doing so.

    For more information on managing or withdrawing consents and how we handle data, visit our Privacy Policy at:

    Show Details
    HubPages Device IDThis is used to identify particular browsers or devices when the access the service, and is used for security reasons.
    LoginThis is necessary to sign in to the HubPages Service.
    Google RecaptchaThis is used to prevent bots and spam. (Privacy Policy)
    AkismetThis is used to detect comment spam. (Privacy Policy)
    HubPages Google AnalyticsThis is used to provide data on traffic to our website, all personally identifyable data is anonymized. (Privacy Policy)
    HubPages Traffic PixelThis is used to collect data on traffic to articles and other pages on our site. Unless you are signed in to a HubPages account, all personally identifiable information is anonymized.
    Amazon Web ServicesThis is a cloud services platform that we used to host our service. (Privacy Policy)
    CloudflareThis is a cloud CDN service that we use to efficiently deliver files required for our service to operate such as javascript, cascading style sheets, images, and videos. (Privacy Policy)
    Google Hosted LibrariesJavascript software libraries such as jQuery are loaded at endpoints on the or domains, for performance and efficiency reasons. (Privacy Policy)
    Google Custom SearchThis is feature allows you to search the site. (Privacy Policy)
    Google MapsSome articles have Google Maps embedded in them. (Privacy Policy)
    Google ChartsThis is used to display charts and graphs on articles and the author center. (Privacy Policy)
    Google AdSense Host APIThis service allows you to sign up for or associate a Google AdSense account with HubPages, so that you can earn money from ads on your articles. No data is shared unless you engage with this feature. (Privacy Policy)
    Google YouTubeSome articles have YouTube videos embedded in them. (Privacy Policy)
    VimeoSome articles have Vimeo videos embedded in them. (Privacy Policy)
    PaypalThis is used for a registered author who enrolls in the HubPages Earnings program and requests to be paid via PayPal. No data is shared with Paypal unless you engage with this feature. (Privacy Policy)
    Facebook LoginYou can use this to streamline signing up for, or signing in to your Hubpages account. No data is shared with Facebook unless you engage with this feature. (Privacy Policy)
    MavenThis supports the Maven widget and search functionality. (Privacy Policy)
    Google AdSenseThis is an ad network. (Privacy Policy)
    Google DoubleClickGoogle provides ad serving technology and runs an ad network. (Privacy Policy)
    Index ExchangeThis is an ad network. (Privacy Policy)
    SovrnThis is an ad network. (Privacy Policy)
    Facebook AdsThis is an ad network. (Privacy Policy)
    Amazon Unified Ad MarketplaceThis is an ad network. (Privacy Policy)
    AppNexusThis is an ad network. (Privacy Policy)
    OpenxThis is an ad network. (Privacy Policy)
    Rubicon ProjectThis is an ad network. (Privacy Policy)
    TripleLiftThis is an ad network. (Privacy Policy)
    Say MediaWe partner with Say Media to deliver ad campaigns on our sites. (Privacy Policy)
    Remarketing PixelsWe may use remarketing pixels from advertising networks such as Google AdWords, Bing Ads, and Facebook in order to advertise the HubPages Service to people that have visited our sites.
    Conversion Tracking PixelsWe may use conversion tracking pixels from advertising networks such as Google AdWords, Bing Ads, and Facebook in order to identify when an advertisement has successfully resulted in the desired action, such as signing up for the HubPages Service or publishing an article on the HubPages Service.
    Author Google AnalyticsThis is used to provide traffic data and reports to the authors of articles on the HubPages Service. (Privacy Policy)
    ComscoreComScore is a media measurement and analytics company providing marketing data and analytics to enterprises, media and advertising agencies, and publishers. Non-consent will result in ComScore only processing obfuscated personal data. (Privacy Policy)
    Amazon Tracking PixelSome articles display amazon products as part of the Amazon Affiliate program, this pixel provides traffic statistics for those products (Privacy Policy)