My Vortec engine build.

Discussion in 'High Performance Modifications' started by ClassicRob1977, Jul 20, 2021.

  1. Bandit723

    Bandit723 Veteran Member

    Messages:
    3,670
    Likes Received:
    677
    Joined:
    Oct 1, 2016
    Location:
    Waupaca WI
    I am questioning why you are running a 602 crate engine with 1-5/8 th headers. big blocks normally are 2 inches or better and that goes for the stock manifolds.
     
  2. 1980RS

    1980RS Veteran Member

    Messages:
    5,503
    Likes Received:
    1,809
    Joined:
    Jun 17, 2006
    Location:
    MN
    So I will lay this one on you, last year the 062 Vortec went [email protected] with 1 5/8" cheapo headers and with my Super Comps not any quicker. Same goes for my BBC stuff, the peanut port 454 went 11 [email protected] 119 with 1 3/4" headers and slows down a lot with the Hooker 2" Super Comps. Why? because the bigger headers make less torque, that's why. To tell you the truth, I was pretty shocked when the 406 Vortec engine went that quick with those tiny headers.
     
  3. Chevyforever

    Chevyforever Veteran Member

    Messages:
    1,127
    Likes Received:
    453
    Joined:
    Jan 4, 2011
    Location:
    Ontario, Canada
    So I just looked up my intake manifold A/B dimensions. A=4.13" and B=5.21" and with a typical drop base bottom on my 14" air cleaner I can not fit a 3"tall filter element. The lid of my air cleaner sits on the top of the bowl vent on my Holley carb, which is less than ideal. I use a K&N extreme top to get a bit more airflow into the engine. My hood is the stock 1980 Z28 "air induction" model, and the air cleaner rubs the hood lightly at the front !

    IMG_2388.JPG
     
  4. Bandit723

    Bandit723 Veteran Member

    Messages:
    3,670
    Likes Received:
    677
    Joined:
    Oct 1, 2016
    Location:
    Waupaca WI
    not going to argue by no means. speed shop in town has a car "the joker" does low 9's and has the larger pipes. bu that does not mean one's setup does not work for them using smaller tubes. i run 2" pipes and do notice the lower torque but i also gained HP.
     
    1980RS likes this.
  5. 1980RS

    1980RS Veteran Member

    Messages:
    5,503
    Likes Received:
    1,809
    Joined:
    Jun 17, 2006
    Location:
    MN
    I know for sure a bigger cam, heads and engine all demand a bigger diameter primary tube but it the key is on torque and the engine is 6K less then a smaller tube is a better choice. My friend who races an A/SA Camaro said the biggest help with the larger tube headers was to add a merge collector, he was saying it really picked up the car a lot.
     
    ClassicRob1977 and Bandit723 like this.
  6. ClassicRob1977

    ClassicRob1977 Member

    Messages:
    72
    Likes Received:
    29
    Joined:
    Jun 21, 2021
    I decided to do some comparisons to see how much taller the 573 is compared to the Winters Z28 which we know will fit.
    wintersvsvortec.jpg

    Just look at those ports on the Winters intake compared to the Vortec!
    wintersvsvortec2.jpg

    I tried a few ways doing this, one by supporting the mounting faces of both intake manifolds and that had a lot of variance. Visually I can tell you the 573 doesn't appear to be much taller than the Winters. The closest measurement I could obtain was mocking them up on a box where the intake manifold is sitting on the ends with the bottom being able to be inside the box. This would simulate the intakes sitting on the valley rails and then I put a straight edge across them side by side. The 573 is 4/32"-5/16" taller here but this is really a rough measurement.

    516vvsw.jpg

    After that I said screw it, the heads are still on the car and guess what isn't? Yep! So I went into the garage and placed both intakes to where they were sitting on the block.

    Winters
    wintersintakecar.jpg
    Vortec
    vortecintakecar.jpg

    As you can see, there really isn't much difference between the two. Without my air cleaner assembly here, I really saw no point in mocking up the carb. As it stands right now, I think I am going to be ok. That fender cover behind the intake on the cowl is hanging off quite a bit. The flanges of the G braces aren't even visible and thats another inch and a half. I think this is going to make it.

    I tried calling Ricks today (Ecklers) to check on my air cleaner that hasn't even been labeled for shipping apparently, but their customer service has literally gone to nothing. I held for 30 minutes one call and 10 for another. No answer. Frustrating to say the least.
     
    Chevyforever likes this.
  7. ClassicRob1977

    ClassicRob1977 Member

    Messages:
    72
    Likes Received:
    29
    Joined:
    Jun 21, 2021
    As mentioned before, I got a carb already. I went with the tried and true 4150 650cfm double pumper with electronic choke. I really didn't want to hassle with a car that wouldn't start when it was cooler for the 1hp it might lose - if that! I opted for the dichromate finish as I am not a fan of the aluminum versions. I think its a good looking carb! No doubt the future of this carb is going to be a modified future.
    carb1.jpg
    650.jpg

    As for the headers, I am still on the fence. I bought some because the owner told me I would have no problems with fitment. They are the Sanderson CC17 Vortec specific short tube 1 5/8" headers which should fit a 4 speed car. I honestly wanted long tubes and I am still looking for a set. I'm not real happy about the quality of these. There is welding slag on the insides of the tubes and they did not clean them up very good before coating them. The good is... The coating is decent, and done well. They actually line up really well with lots of room near the plugs, the ports are spot on too. The only thing I need to do is check if the Z-bar will get in the way. Heres a quick shot of the headers mocked up. The bolts are really close to the primaries on a couple spots. Close enough to have to use an open ended wrench but you can still thread them easily. These are coated inside and out and ran me about $650 bucks.

    sandersonports.jpg
    sandersoncollector.jpg
    sandersonporttoport.jpg
    sandersoncc17.jpg
    headsheaders.jpg


    Theres been a few folks who have warned me about Vortec exhaust ports being taller than the tubes on the headers, and then others about the collector flanges hitting the floors. Honestly, I am willing to give up HP vs beating the floor of the car. It's just not going to happen. So purchasing a quality set of headers without spending $800-1300 has become a challenge. I REALLY wanted the Dynatech headers and called to get a set only to find out they don't even make them anymore. I searched high and low for a set sitting somewhere but NOTTA!

    I am going to have to revisit this issue again before final assembly.
     
  8. ClassicRob1977

    ClassicRob1977 Member

    Messages:
    72
    Likes Received:
    29
    Joined:
    Jun 21, 2021
    I agree. Exhaust tubing is no different than intake I.D., cross section, etc. There's a size thats right and wrong for any combination. I've seen 1 5/8" stuff do some pretty impressive feats back in my fox body days.
     
    1980RS likes this.
  9. biker

    biker Veteran Member

    Messages:
    3,786
    Likes Received:
    1,784
    Joined:
    Dec 7, 2014
    Location:
    Canada
    I think "602" is a GM designation part number for a 350 small block circle track engine. Not 602 cubic inch big block. All the numbers DO get confusing.
     
    sandlapper and 1980RS like this.
  10. Bandit723

    Bandit723 Veteran Member

    Messages:
    3,670
    Likes Received:
    677
    Joined:
    Oct 1, 2016
    Location:
    Waupaca WI
    I did the jet hot coating on my headers it has been holding out. as to the smaller pipes and exhaust it has its bonuses as well as it's downside. I do run 3'inch exhaust pipes and 2 inch tubes off the heads. and yes i do loose some torque but gain hp.
     

Share This Page