406
 

Hello everyone ,
This is my first post and could use some info .Problem is my arp studs that I have coated with arp thred sealer durning the build are leaking (only distelled h20 no antifreeze )after start up .I did not see any leaks after first run only 5 min.After second run up to temp around 150 leaks of water out of lower head bolts So i pressure tested it to 10 lbs and almost all leaked .Why WHY WHY :mad:

what was the torque set at when you built the engine?

Did you chase and clean the threads in the block prior to installation?

406
 

Thank u for a respond ,I followed the arp install instruk of three eq steps to 80 ft lbs.

I did and so did the machine shop

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IDK maybe i just didnt use enough .I dont think i went crazy with the stuff just enough to cover the stud threads 50% maybe .the build started back in march piece by piece as i could afford parts .Today I am rebuilding the 4160 carbs .

ARP cylinder heads studs often leak. They are a race engine part only. There is no place or need for these
on a street motor. Replace with good head bolts and coat the threads with BLACK Permetex gasket sealer
on the threads and bit under each head of the bolt or washer.

You can remove and reseal the studs but they will likely leak again.
Again the Black Permetex gasket sealer works better for sealing bolts and studs.

the thead cut on the ARP studs is slightly different than the threads in the block.
coolant creeps up the threads.
You are best to not used them at all on a street motor. You don;t need them.

Race engine blocks have blind head bolt holes in the block. That don;t leak coolant
the studs are not a problem on a race block with blind bolt holes. But all too often area big pain on stock blocks.
They are not needed any way.

thanx for the tip i agree .So do u think i would most likely have the same water problem with my dart shp rocker arm studs ?

I use Permatex #2 in the tube. Permatex Aviation p/n 80019 in the bottle will work too.

Some SBC exhaust rocker studs go into water and need sealing too.

I like this forum very helpful.Here is a question for all u
hotroders out there
What are the thoughts of the amount of hp and compression from this build?


1974 400 block machine shop to .030 over >406
line bored shop balanced on newest machine
(shop tells me its the newest ballancer on the market )
castcrank
(now i wish i would of went forged)
flat top pistons with two releif cuts
mahle rings
howard cam .555/298/308/110hyd roller
crane roller rockers (gold pro race 1.5)
dart shp 202/180 72cc on stock deck height
comtiec gasket compressed 0.30
weiand tunnel ram with twin 4160 450 cfm carbs
holly hp mech fp 110gph
msd plug and play msd wires msd coil
Super Competition, Full-Length, Steel, Ceramic Coated, Chevy Headers

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Ill be in the garage today rebuilding my second holly today so i wll check back later thanx everyone.

The tiny 450 carbs will not make horsepower power on a tunnel ram.
They are T bucket cruiser-poser carbs.
Get real 650+cfm DP carbs for it.
Edelbrock 750's work well too.

They make engine test dynos to determine HP.
Get some real carbs and dyno it.
The HYD cam will run out of steam and limit power and rpm.
This is a poser girlie-man motor.

Using the right springs and heads that cam will make power to about 6,500, and you will need some stall if it's an automatic.

Poser girlie-man motor?? Now that's funny...

Fbirds right about the carbs. I don't have time to do the math but I'd bet the compression will be low for the cam.