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-   -   BBC 509cid tunnel ram efi build. (https://www.offshoreonly.com/forums/general-q/381984-bbc-509cid-tunnel-ram-efi-build.html)

JaniH 05-27-2024 03:00 PM

With milodon pan i cannot use the gm original main bolts, so i bought arp 135-5201 main bolts and found out that the arp bolts are 0.150" shorter compared to gm bolts, I quess this is not a problem? Arp only lists this kit for gen IV/gen V.

Tartilla 05-27-2024 10:19 PM


Originally Posted by JaniH (Post 4898182)
Heads are ready. ferrea 6000, int 30dg backcuts, new seats, bowl/short turn blend, good port had too high air speed @.600 and up, trimming the head bolt pump fixed the problem. 1=good port, 2=bad port, 3=exhaust no pipe, 4.5" bore adapter.


https://cimg2.ibsrv.net/gimg/www.off...85a78e85e8.png

The 0.400" loft is pretty good. Exhaust doesn't choke off at higher lift/flow. They should make some good power. What seats did you end up using?

JaniH 05-27-2024 11:09 PM


Originally Posted by Tartilla (Post 4899059)
The 0.400" loft is pretty good. Exhaust doesn't choke off at higher lift/flow. They should make some good power. What seats did you end up using?

Have to to ask about the seat angles. Quess that the 650-675hp might be possible. Now i try to decide what icl i instal the cam.

Tartilla 05-28-2024 02:34 AM


Originally Posted by JaniH (Post 4899060)
Have to to ask about the seat angles. Quess that the 650-675hp might be possible. Now i try to decide what icl i instal the cam.

My bad...was looking to see what metal style of seats you used. Powdered metal?

JaniH 05-28-2024 03:46 AM


Originally Posted by Tartilla (Post 4899063)
My bad...was looking to see what metal style of seats you used. Powdered metal?

Yes, powdered metal

JaniH 05-30-2024 03:00 PM

Starting to steer away from these arp bolts. How many threads should be engaged in the block? I know the old rule for depth is the thicknes of the bolt, but i am barely there with these.
https://cimg2.ibsrv.net/gimg/www.off...1bd359803b.jpg

Brad Christy 05-30-2024 04:15 PM


Originally Posted by JaniH (Post 4899263)
Starting to steer away from these arp bolts. How many threads should be engaged in the block? I know the old rule for depth is the thicknes of the bolt, but i am barely there with these.
https://cimg2.ibsrv.net/gimg/www.off...1bd359803b.jpg

Jani,

Conventional wisdom holds that 1-1/2 X thread diameter will achieve maximum thread strength. Personally, I like as much as I can get, and have designed parts with 2-1/2 to 3 X thread diameter, just to make myself feel better about them. I haven't the foggiest on head bolts, but I'd think you'd want considerably more thread engagement than single thread diameter.

Thanks. Brad.

Sporl Performance 05-31-2024 06:00 AM

Put studs in.

JaniH 05-31-2024 08:33 AM


Originally Posted by Sporl Performance (Post 4899284)
Put studs in.

Do i need to line hone the mains then?

sutphen 30 06-01-2024 08:33 AM


Originally Posted by JaniH (Post 4899297)
Do i need to line hone the mains then?

you should


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