3 or 5 main

Tech tips and how to's

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BAMUZ
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Posts: 132
Joined: Thu Jan 06, 2022 7:57 pm
Location: North Carolina
Model: 1500/1600
Year: High Windshield-68-70

Re: 3 or 5 main

Post by BAMUZ »

DAC21 wrote: Sun Aug 13, 2023 5:52 pm
Daryl Smith wrote: Sun Aug 13, 2023 4:10 pm "Looking into strokers and came across the 3 or 5 talking point"

BAMUZ,
1) Your head has the air injection ports at the exhaust, so is definitely a metric head. Likely the block is also, but to be sure you will need to check a bolt/nut somewhere....Not the headbolts, they're all SAE...

2) Having built both a 3 main and 5 main stroker, I would advise to stick with the 5 main metric block. U20 or H20 cranks are more available, as are bearings etc. vs the G15 crank, which is also a bit more fragile. G15 crank will also limit you to about 1800cc where as you will get about 2000cc and more power and torque with the U/H20 cranks.

Pat, okey dokey, that's what I thought, and why I was hoping it could be turned around.....damn.
I saw those tubes on the head, but no air injection on the intake ports. Frankenstein motor?
I’ve been wondering a lot myself haha
I seen the other posts and will check them out cause to be honest, I was wondering what was going on haha
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70 1600 #29574
68 1600 #18273
My Roadster Builds viewtopic.php?t=37670
16 Promaster 1500
23 Santa Fe
04 Colorado
User avatar
BAMUZ
Roadster Fanatic
Posts: 132
Joined: Thu Jan 06, 2022 7:57 pm
Location: North Carolina
Model: 1500/1600
Year: High Windshield-68-70

Re: 3 or 5 main

Post by BAMUZ »

Daryl Smith wrote: Mon Aug 14, 2023 9:10 pm Well, yes, it is part of the smog system, but, those are not 'air injection ports'.
I don't know how the system works, honestly, or what the connection to the intake manifold is for, except maybe to regulate the air injection via manifold vaccuum??

There is a picture on this thread part way down showing the top portion of the system where it connects to the intake manifold and head, and then the picture below it shows the smog plugs installed.
https://grassrootsmotorsports.com/forum ... 586/page1/
Definitely will do the same thing to clean the block up.
Appreciate that 🤙🏼🤙🏼
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70 1600 #29574
68 1600 #18273
My Roadster Builds viewtopic.php?t=37670
16 Promaster 1500
23 Santa Fe
04 Colorado
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