Inlet Manifold question: education required | The Z Club of Great Britain
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Inlet Manifold question: education required

Discussion in 'S30 (240Z,260Z,280Z) Engine' started by tyroguru, Sep 25, 2019.

  1. tyroguru

    tyroguru
    Z Club Member

    This is probably a general engine theory 101 question and I'm looking for tuition :) .

    I have a '73 HLS30 with a standard E88 head on a P30 block (I have no idea if they've been previously molested/machined in any shape or form though). I'm doing some future planning and dreaming and I'm looking at inlet manifolds such as the Magoletsi, the Harada and Jenvey's offering.

    The inlet ports on the E88 head measure at 34mm but the Jenvey manifold is 40mm diameter at the manifold runner exit. I can't find cylinder head port dimensions for the Mangoletsi or the Harada (small or large) at the minute though. Shouldn't the inlet manifold runners match the port size on the head? Wouldn't a situation where the runner diameter is greater than the head port diameter cause turbulence on the airflow? Does it even matter?

    Is it just that the Jenvey offering is only suitable for other heads and the Harada/Mangoletsi would be suitable for me or do I need a different head? I don't mind spending money - just ask my wife :) .

    Thanks.

    Jon.
     
  2. richiep

    richiep
    Z Club Member

    The Harada outlets are 35mm at the head face. I THINK the Mangoletsi ones are 37mm. Obviously, the Mangoletsi comes with a porting template to help match the head and manifold.

    I'd say, if you aren't going to engage in significant molestation of the head ports, other than basic port matching, the Harada would be the least effort. I'm biased though; I have two Harada Shoukai manifolds, and think they are excellent quality, flexible (come with both adjustable rod linkage and alternative hardware for a cable) and comparatively cheap. One is port-matched and polished internally to 180 grit to match the lightly ported N42 in my red Z. The other will be more radically ported to match the big bore head that my project car's stroker will be running.
     
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  3. SeanDezart

    SeanDezart
    Z Club Member
    Official Trader

    I have two new Mangoletsi manifolds at home (40 and 45mm outlets) and I'll measure them when I can.
     
    tyroguru likes this.
  4. tyroguru

    tyroguru
    Z Club Member

    Thanks Richie - that's really helpful. Looking at rhdjapan I see that they have different SKUs for a 44mm Harada Shoukai manifold and a Kameari manifold but I assume Kameari just resells the Harada Shoukai (?). The description states "Intake Manifold Kit L-Type L6 44mm" but the specification states "Manifold Size: 42mm" . Any idea why there is a difference there or what the different dimensions refer to? The reason I ask is that I've seen reference to a big and small Harada manifold although see no reference to two such beasts on rhdjapan anyway.

    That would be fantastic - many thanks Sean.
     
  5. Albrecht

    Albrecht Well-Known Forum User

    Harada Shōkai manufacture two different inlet manifolds for the L6: One for 40mm/44mm/45mm carburettor bodies and one for 48mm/50mm carburettor bodies. It's the two carburettor body size PCDs that are different, but the bores in the respective manifolds are different too, as you might expect. Generally speaking, the manifold castings for the bigger carb bodies have bigger bores on the head side. I believe Mangoletsi offer the two sizes too?

    Other inlet manifold manufacturers - such as Sanyo Kiki/SK, Kyokuto/FET, Tomei etc - all used to make the two sizes, however some of them - including Harada - also supplied a 40mm version with small bores to suit the L20/L20A/L20AE sixes. I don't think Harada make them anymore.
     
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  6. richiep

    richiep
    Z Club Member

    Yes, Kameari just resell the Harada.

    Sometimes the RHDJapan description info is incorrect, and in this case they’ve doubled up on the SKUs, listing the same kit twice, once as Harada, once as Kameari.

    Also worth noting that the ‘wire type’ and ‘rod type’ versions they list are identical. The kit comes as standard with the full rod linkage but also the fittings to allow a generic cable to be fitted. I used a 25 quid Venhill cable off eBay as shown somewhere in the “what did you do to your Z” thread.

    As Alan notes, there is the 40-45 version and the 48-50, the latter looking a bit different due to the mounting of the linkage.

    https://www.rhdjapan.com/kameari-intake-manifold-kit-l-type-44mm-l6-wire-type.html

    https://www.rhdjapan.com/kameari-intake-manifold-kit-l-type-50mm-l6-wire-type.html
     
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  7. tyroguru

    tyroguru
    Z Club Member

    Thanks Alan and Richie - this is super helpful for me.

    classiccarbs.co.uk (for example) sell both these for around the 500 GBP mark (they offer a 40 and a 45). I've just been reading the specification for the Mangoletsi manifolds and it reads like they both have a port diameter at the head of 35mm.

    The 40-45 will be ample for my needs I would think and I like the linkage more anyway :) .

    Thanks again everyone for the input.
     
  8. SeanDezart

    SeanDezart
    Z Club Member
    Official Trader

    Sorry, only got back in late last night after a prolonged PTA meeting.

    Confirm with Classic carbs (if buying through them !) that their kit is complete with linkage !
     
  9. Rob Gaskin

    Rob Gaskin Treasurer Staff Member Moderator

    I have an Mangoletsi for 40s but it's not easy to get to atm (with webers in my loft). Yesterday I measured a manifold I have (unknown manufacturer) and the dia at the head is 34/35mm and 40mm at the carbs (Dellorto).

    Anyboby know the manifold? 20190531_165756.jpg
     
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  10. SeanDezart

    SeanDezart
    Z Club Member
    Official Trader

    A photo of the other side please ?
     
  11. Albrecht

    Albrecht Well-Known Forum User

    The '470' casting mark is usually attributed to early Mangoletsi manifold castings, as far as I am aware. Quite often used on 'Samuri' conversions, and painted crackle red:
     

    Attached Files:

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  12. jonbills

    jonbills
    ZClub Administrator
    Staff Member Moderator

    Fwiw, I think it's reasonably important to try to match head to manifold and manifold to carb/itb. When I had my head made, the manifold and head were ported together to 38mm and dowelled to ensure alignment.
     
    Last edited: Sep 26, 2019
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  13. SeanDezart

    SeanDezart
    Z Club Member
    Official Trader

    35mm* at the head and I have two versions here : 40mm and 45mm

    *ripe for porting and matching with the cylinder head of course.
     
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  14. tyroguru

    tyroguru
    Z Club Member

    Thanks guys for the all measurements and the photo's. I'll probably go for the Harada but I'm not sure there's a lot between them - I'll do some more reading. I think I'm going to go the ITB route so this is all part of the planning for that adventure.
     
  15. franky

    franky
    Z Club Member

    That seems the best balanced choice. Its very well proven/designed and the cheapest.
     
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  16. status

    status
    Z Club Member

    That looks the same as mine rob which has a slightly smaller depth compared to the Webber manifold,
     
  17. jonbills

    jonbills
    ZClub Administrator
    Staff Member Moderator

    I've removed all the off topic boring ping pong. Please stay on topic.
     

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