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Technical Chevy inline six

Discussion in 'The Hokey Ass Message Board' started by dkWayfarer50, Feb 12, 2019.

  1. dkWayfarer50
    Joined: Aug 18, 2014
    Posts: 185

    from Denmark

    Hi. I just got me a GM inline six from a TORO parkmaster (lawn mower) casting nr.377127 says 250" '73-'79. As far as i can see the tractor is a '77. Its only been used in the 6 month of summer, here in Denmark () until 2016. Its always been used by the the public authority, so its been at service 1 or 2 times a year. I like to here your experiences with these engines: how to make it a strong hot rod engine, parts, horsepower as stock, any well known problems, is it possible to buy a adapter for a 5 speed man. Transmission?

    Sorry for the bad pictures - my work phone has alot of scratches on the lense

    Thanks in regards
    Andreas from Denmark IMG_0243.jpeg IMG_0231.jpeg IMG_0232.jpeg IMG_0244.jpeg

    Sent from my SM-G955F using The H.A.M.B. mobile app
    chryslerfan55 likes this.
  2. Mr48chev
    Joined: Dec 28, 2007
    Posts: 25,362


    <<<<<---- I put over a hundred thousand miles on one in my 48 that had 94 thousand on it when I installed it. good solid reliable engines.

    Transmission wise they use a Chevy V8 Pattern bellhousing. That makes it reasonably simple even in Denmark as the hunting isn't that complicated.
    Flywheel you can run a 153 tooth ring gear or 168 tooth ring gear but have to have the starter to match. I would see what is on the engine and figure out If I could use it.
    There are plenty of dress up pieces for the engine if you want to dress it up but I would wait until I had done some miles in the vehicle I put it in before spending money to dress it up with shiny stuff.
    5 speed, you might find a 5 speed Camaro or Firebird over there as a donor.
    There are also some adapters that may allow you to Adapt a Toyota W series 5 speed to the engine. The adapters are a bit expensive but You might be able to find a 5 speed out of a Supra rather inexpensively compared to buying a T-5 and a chevy bellhousing and all the other pieces and maybe paying shipping. It's total cost not individual parts cost.
    I don't know what your monetary conversion rate is to Australian but this company lists a number of adapters that you might find interesting for a 5 speed conversion.
    Those are just some ideas and options to peruse.
  3. Rusty O'Toole
    Joined: Sep 17, 2006
    Posts: 8,975

    Rusty O'Toole

    This was a new six cylinder for Chevrolet passenger cars and light trucks introduced in 1962. It was made as a 194, 230 or 250 cubic inch engine with a special raised deck 292 for trucks only. It was used in cars up to 1979 and trucks up to 1984.

    The 250 produced 155 horsepower. The last versions had the intake manifold cast integral with the head, you are lucky that your engine is the older style with separate manifold.

    They were very detuned in stock form and you can get more HP out of them with the usual hot rod tricks of better camshaft, carburetor, headers, etc. But, the cylinder head design is not at all performance oriented, being made for economy and good low speed torque. So there is a limit to how much you can get out of them at a reasonable cost.

    They have a strong 7 main bearing bottom end and many parts interchange with the Chevrolet small block V8. There is performance equipment available from companies like Clifford, a six cylinder specialist, and older speed equipment makers like Isky cams, Edelbrock or Weiand manifolds etc.
    belair and squirrel like this.
  4. Rusty O'Toole
    Joined: Sep 17, 2006
    Posts: 8,975

    Rusty O'Toole

    As Mr 48 pointed out they use the same bellhousing as a Chev V8. So you could use a 5 speed out of a Camaro, S10 or S15 pickup truck or Astro van. It should also be possible to adapt a European transmission by drilling the bellhousing or making an adapter plate.

    Chevrolet used the Borg Warner T5 or Tremec T5 5 speed transmission in Camaros, Firebirds, and light trucks and vans. They are all very much alike and parts interchange. The Camaros and Firebirds have the gearshift lever offset to the rear, the trucks and vans have it coming straight out of the top of the trans. This makes the truck version preferable for older cars. The trans top can be changed easily if necessary.

    This trans was used in AMC, GM, Ford, Jeep, Nissan 280ZX and 300ZX. For complete list look here.

    It may be possible to find one in Denmark, you never know your luck.
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  5. Rusty O'Toole
    Joined: Sep 17, 2006
    Posts: 8,975

    Rusty O'Toole

    This engine would be a bolt in swap for Chevrolet cars and light trucks back to 1955. Will fit the older Chevs with torque tube drive back to 1937 if you have the right trans case. There were 2 trans cases, they were used more or less at random but the one that fits the newer bellhousing is more often found in pickup trucks. The one that fits the later bellhousing was used from 1942 to 1954. After that they changed the torque tube drive to open driveshaft.

    I agree that it would be best to try it in stock form first, and only think of a hop up if you aren't happy with the performance. They are a strong smooth running engine well suited to a light car like a Nova, or a Chev of the fifties or forties.
    Last edited: Feb 12, 2019
  6. buffaloracer
    Joined: Aug 22, 2004
    Posts: 772

    from kansas

    I put over 300,000 miles on a 250. Very likeable engine. I'd suggest you find the book
    by Leo Santucci on how to hop one up.
  7. squirrel
    Joined: Sep 23, 2004
    Posts: 43,174


    But how many of these actually bolt in to a Chevy easily? There are many flavors of T5, make sure you get the one you want. If the case bolt pattern, or input shaft, is not designed to fit the Chevy V8 or 90 degree V6, you will have to do some work to make it fit.
  8. oldtom69
    Joined: Dec 6, 2009
    Posts: 389

    from grandin nd

    did you get the whole parkmaster to part out?May be a dana 60 rear,too wide but possibly good ratio gears.they were quite the "lawn mower"
  9. ol-nobull
    Joined: Oct 16, 2013
    Posts: 1,244


    Hi. The 250 engines are really great running engines. They are just a bit longer than the earlier 235 and 216 Chevy engines though. My avitar on this reply shows the 235 Chevy engine with the Clifford dual intake and exhaust set up. Those are 2 two barrell Weber carbs on it. Jimmie
  10. s55mercury66
    Joined: Jul 6, 2009
    Posts: 3,614

    from SW Wyoming

    The only issue I have had with the ones I have had, is with the distributor wearing, and that has been a problem on all of the ones I have owned. Nothing really major, but it does make setting the points and getting proper dwell a problem. With the HEI on yours, it may not be as much of an issue.
  11. Mr48chev
    Joined: Dec 28, 2007
    Posts: 25,362


    Gents, remember that dkwayfarer50 is in Denmark and rigs with T-5 transmissions might be in short supply while the supply of strong rear wheel drive 5 speed for some other vehicles that are real common in Europe are good and fairly inexpensive. It doesn't have to be an "American" transmission, it needs to be one that he can readily find and can find parts for if needed. The cost of an adapter from Australia might seem a bit high but the cost of buying a T-5 from the US plus the attending pieces and paying shipping might be seriously higher when all is said and done.
    Hnstray likes this.
  12. Rusty O'Toole
    Joined: Sep 17, 2006
    Posts: 8,975

    Rusty O'Toole

    In Denmark it might be easier to find a transmission from a Volvo, Mercedes or BMW. As long as it comes from a car with similar torque and horsepower it should be strong enough. It is usually possible to adapt a transmission by drilling holes in the bellhousing or making an adapter plate and finding a clutch plate of the right diameter with suitable splines in the center. This is not rocket science. But, it would be easier to use one made for a Chevrolet like an S15 or Astro van. Those would work better in a traditional car, than a Camaro unit with the gearshift offset to the rear.
  13. Oldioron
    Joined: Dec 12, 2018
    Posts: 836


    I could be full of bs but I seem to remember a friend who used 327 pistons in a 250, with a cam and headers the Camero was ear piercing going through the gears.:cool:
  14. Casual 6
    Joined: May 25, 2008
    Posts: 218

    Casual 6
    from Great NW

    FYI - Lots of NOS parts will be available soon. 12Bolt also has high performance parts and has done extensive dyno testing comparing different builds with Chevy 6's.

    Information and parts

    Exciting News. 12Bolt LLC has bought all the inventory of GM parts from Studebaker International.
    What does this mean? Back in 1965 Studebaker was using GM engines in their production cars. Inline 6 and V8. This continued into 1966. The parts inventory was maintained and stored all these years.
    almost every part needed to build one of these engines was still available.
    A sampling of the stock. All NOS parts.
    nearly 50 blocks fitted with pistons and bearing.
    50 cylinder heads. Thousands of valves
    Steel shim head gaskets
    50 carburetors and parts to fix/ repair carbs
    fuel pumps and repair kits
    Fuel lines
    Kits for every part of the engine.
    It was all packed and is heading to 12Bolt in Iowa.


    There are over 100 steel shim gaskets.
    44 oil pans
    25 distributors
    20 Valve covers
    25 timing covers
    The good style AC fuel pumps 30?
    Rebuild kits for those 100?
    Fuel lines
    Vacuum lines
    Sparkplug wires.
    Every conceivable part for a distributor or a starter.
    oil pumps
    main caps
    water pumps and parts to rebuild them.
    And the list goes on and on.

    Once it all gets inventoried, the list will go on the website.

    The same goes for the 283 V8 parts.
  15. Jethro
    Joined: Mar 5, 2001
    Posts: 1,401


    You're pretty close!...The 250 has the same piston as a 307.
    Oldioron likes this.
  16. Oldioron
    Joined: Dec 12, 2018
    Posts: 836


    I was trying to remember from 1977, I guess my memory isn't is bad as I think.
  17. Jethro
    Joined: Mar 5, 2001
    Posts: 1,401


    If you could bore a 250 1/8 inch you could fit the 327's.....they're pretty thin castings though.
  18. David Chandler
    Joined: Jan 27, 2007
    Posts: 1,096

    David Chandler

    Flat topped pistons from a 307 will fit. Check out inliners web site. They have 250 Chevy stuff discussed there often. A 292 exhaust manifold with a 2 1/5 inch outlet will fit, but the alternator bracket need to be slightly reworked. Split cast iron manifolds are available from Tom Langdon. I think he's found under I had it on my old computer, but it died. Intakes are still made for different carburetor options, by Offenhouser and others. Cam's can still be found for them too. The HEI distributors from newer engines can replace the single point distributors found on the older ones. Bigger valves can be installed as well. And the cylinder head can be made better various ways to get around the issue of the head bolt boss running through the inlet ports. Great engines for light vehicles. I've had several over the years. They are hard to kill. At the moment I have two lower ends and one cylinder head. I made an adapter for a Rochester 2 barrel from a 307 for it, and have the 292 exhaust manifold, and a Mercruiser cam shaft. Someday I'll finish it and put it into something.
    Good luck, Hope this helps!

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