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-   -   is this guy legit? 2-bolt mains stronger than factory 4 bolts? (https://www.hotrodders.com/forum/guy-legit-2-bolt-mains-stronger-than-factory-4-bolts-522253.html)

OC_ 08-02-2019 10:12 AM

is this guy legit? 2-bolt mains stronger than factory 4 bolts?
 
https://westcoastengines.com/2-vs-4-...into-the-myth/

To me, it seems like this guy is all over the place. He says the EPA was enforcing NVH standards. Thats BS, the epa doesn't care about noise vibration and harshness at all!

I think hes trying to say that out of SBC blocks manufactured in the 80's and 90's, the 2 bolt main ones are better.

johnsongrass1 08-02-2019 12:11 PM

Horse Sh%t all over the page.

Never has any documentation ever been produced to inclue any blocks having more nickle in the casting process. To add to that, several have tested the theory with alloy testing that showed it's all nodular iron.

To add, Stock blocks with four bolts straight in, tend to be weaker because the bolts pull the main webs differently than those with 2 bolts. With 2 bolts, you can drill them at at angle and avoid this. Adding a cast iron 4 bolts caps to a 2 bolt block helps some because the caps tend to be thicker and the registers have more contact area however, it's still at cast cap.

Lastly, buying an aftermarket Dart block isn't a bad idea for $1750 but they aren't ready to go either. They still need squared up and that basic machining adds another $500ish for a total of $2300. They are a good block that last a long time for sure however a stock block with splayed caps and squared up is still around $1000 typically. So a difference is $1300 buys some longevity and strength and that's a lot of dough for the power of most street machines.

In the engine world, the progressiveness of parts and machining is never ending. It's always a few more bucks for the next best thing. Where is the end point lie? How many times can a guy pay "just a few more bucks" before it all adds up to nonsense?

BogiesAnnex1 08-02-2019 12:26 PM

Part nonsense part not.

I have doubts that Chevy ever used nickel in any production blocks regardless of magazine claims otherwise.

Thin wall casting mostly uses less material which saves both money and weight, I'm sure the OEMs worry about it in that order.

The factory 4 bolt main has more to do with spreading the forces over more of the web, the cap stability really comes from that not so much about more clamping force on the cap although that does happen. The aftermarket 4 bolt caps angle the outer bolts into the pan rail where there is more meat to bolt into. The help this brings is now the bulkhead is being somewhat supported by the cap instead of just supporting the cap as in the factory design as some of the loading is being transferred into the pan rail area beyond the bulkhead.

A good balance job and damper does a lot to relieve these center caps of having to deal with loads that would like to put the center of journal rotation somewhere besides the center line of the crank.

You will note that the GEN III and later SBC's use a main cap in girdle arraingement that was also found on the Allison aircraft engines of WW II. The other popular design used by Rolls Royce/Packard and many German and Russian engines of the era was cross bolted mains. The effort not only to stiffen the bottom end but to distribute the crank loads over a greater area of the block.

Bogie

techinspector1 08-02-2019 05:10 PM

"He says the EPA was enforcing NVH standards. Thats BS, the epa doesn't care about noise vibration and harshness at all!"

If you'll do a search on the web, you'll find out differently.
.

joe_padavano 08-02-2019 06:38 PM

But, but, it's on the interwebs so it MUST be true...

OC_ 08-02-2019 09:37 PM

Quote:

Originally Posted by techinspector1 (Post 4687481)
"He says the EPA was enforcing NVH standards. Thats BS, the epa doesn't care about noise vibration and harshness at all!"

If you'll do a search on the web, you'll find out differently.
.

I did. I didn’t find anything. Please show me what you found.

BogiesAnnex1 08-02-2019 10:58 PM

The EPA cares about external noise. The total is capped at so many db at some distance. Obviously everything is making noise but the big contributors are tires and exhaust. I don't see stiffening or strengthening the engine as having a big effect.


However, the motorcycle companies play pretty hard here so they can devote more of the db allocation to exhaust tone than rotating assembly and valve train rattle or gear whine. The Twin Cam and Milwaukee 8 Harley's have a fake timing cover who's purpose is to soak out cam drive noise leaving more space for exhaust noise. I fixed my Twin Cam so I transmit both cam gear whine and loud exhaust which I'm sure far exceed the EPA's miserly limits. But I'm deaf in one ear (exhaust side) and can't hardly hear with the other so with that counter balancer engine I need a lot of noise to hear if it's running.



Bogie

ProStreetRob 08-03-2019 06:12 AM

Through the decades there have been numerous articles on 10 bolt rears are better than 12 bolt, T350's are better than T400's, 2 bolt mains are better than 4 bolt, bla bla bla... Usually they come from people with 2 bolt engines, 10 bolt rears, and T350 Transmissions, LOL

There's Pro's & Con's on everything, which one is; smaller, lighter, quicker, stronger, cheaper to build, etc... Bottom line is if your making BIG POWER you want something that can hold it, and if your making low to moderate hp then you don't need the biggest & baddest. I make 649 RWHP (about 750HP at the crank) so I'll stick with my 9.9" Rear, Tremec TR6060, & 6 Bolt Mains Thank You :cool:

S10xGN 08-03-2019 07:02 AM

Eating bacon is bad for you this week, but wait a month and it'll be the "latest and greatest" superfood.

Russ

BogiesAnnex1 08-03-2019 10:24 AM

My wife is big on lean protein from fish, I prefer North Lake Tavern pizza and a pitcher of PBR. She and my cardiologist say this isn't good for me, but you know somtimes you have to feed your soul as well as your body.

I've been sitting here on the patio with my pittie, who is chasing horse chestnut seed pods falling into the yard, and a pot of coffeee while sneaking a Hostess cherry pie all morning while typing these responses. The summer sun is just peaking above the trees accross the street. I'll head for the shop pretty soon. Life is good.

Bogie

Rip VW 08-03-2019 10:57 AM

Ah it is a good life it is Mr Bogie. I am setting out on the porch just finished a small plate of Blueberry muffins followed up with a gallon of good Coffee. The sun is shining and there is a light breeze blowing and I can hear the ocean waves crashing on the shore..

Ahh as a good friend of mine used to say.. Tis a good life as long as you don't weaken!!:cool:

64nailhead 08-05-2019 06:16 PM

No


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rivvgs 08-08-2019 07:08 PM

Quote:

Originally Posted by OC_ (Post 4687445)
https://westcoastengines.com/2-vs-4-...into-the-myth/

To me, it seems like this guy is all over the place. He says the EPA was enforcing NVH standards. Thats BS, the epa doesn't care about noise vibration and harshness at all!

I think hes trying to say that out of SBC blocks manufactured in the 80's and 90's, the 2 bolt main ones are better.

so I have been told, I have read and been told by my machinist. that the 4 bolt blocks of the 2 piece main seal era where the largest portion of 4 bolt block originate. often have more core shift issues.when over boring a cyl core shift can greatly effect the thickness that is safe to bore. I am not sure why but the latter blocks tend to have less issues

rivvgs 08-08-2019 07:14 PM

although there are less compressive loads, and slower piston speeds. they never made a 4 bolt main 327. research the top OEM hp gen1 small block.many a 7500 rpm 327 roamed the streets

BigMo 08-09-2019 07:17 AM

Quote:

Originally Posted by joe_padavano (Post 4687495)
But, but, it's on the interwebs so it MUST be true...

[emoji106]

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