This block came in the engine shop today and the customer wanted to know why the bearings were tore up and once I pointed out that the center caps were flexing and pinching the bearings that why the copper was showing on the sides of the bearings and the crank was in bad shape and needs to be turned as well.

Notice the registers and how they are fretted and the metal transfer from cap to block as this was a 400 horse 2 barrel circle track engine and this engine was balanced and the pistons show no signs of detonatoin.

This guy read in a magazine that 2 bolt blocks were good for 450 horse and now he has a little different opinion on this. I told him thats why a 2 bolt 400 block have wider center main caps as this helps keep the cap more stable in the register.

Now we will put center splayed caps on this block and I am sure next year the bearing won't look like this.

http://i7.photobucket.com/albums/y276/CNCBLOCKS/flexingcaps006.jpg

Was this block studded or bolts?

Was this block studded or bolts?

It's studed as there using a Canton pan that requires studs to hold the windage tray in place.

We have seen the many times over the years either with studs or bolts as studs do not make the caps any stronger as its still a weak 2 bolt main cap.

If you look closely at the main caps you can see signs of micro welding meaning transfer of metal from the cap to the block.

That's good info Carl, just keep in mind that there are very few (if any) circle track guys on this site.

As we've discussed before there is a big difference between a season of going WOT for lap after lap during a short track feature event and street use with occassional 1/4 mile blasts.

Good luck on your crusade against 2 bolt and factory blocks ;)

That's good info Carl, just keep in mind that there are very few (if any) circle track guys on this site.

As we've discussed before there is a big difference between a season of going WOT for lap after lap during a short track feature event and street use with occassional 1/4 mile blasts.

Good luck on your crusade against 2 bolt and factory blocks ;)

We had a 383 in the shop last month that the customer used a 2 bolt block and the caps and the main bearing were not quite that bad after installing splayed center caps on the block I am sure thing will look mch nicer when disassembled next time.

About 90% percent on the engines we build we use factory 350 blocks in applications up to 575 horse with no problems and these are not 2 bolt main caps.

We have nothing against factory blocks when prepared for the right horse power rating as we seem to get a few of the blocks in shop that guys abuse at the drags and circle track that look similar to the one in the pic its funny we don't see this on the blocks with 2482 center caps and on the splayed cap block HMMMMMMM I wonder why????

The 383 engines GM sells are 4 bolt blocks and not 2 bolt mains I wonder WHY???

The reason I asked is basically what Eric just said. I know my old 385 made close to 500HP (3500 lbs car running 11.90's on street tires) and had years and years of service. It was/is a 2 bolt block with studs. I had it apart to freshen it up before selling it to a close friend, the bearings still looked great and didn't even need to be replaced. That engine is still alive and well today as a 2 bolt.

I think the use of the engine has a lot to do with it too. There are not many forms of racing that is harder on an engine than circle track racing. Good info to have but, would hate to see all the street/strip guys think their 2 bolt block are junk.

I agree with Royce -- circle track has to be about as tough on an engine as you gan get. WOT, then decel, WOT, then decel, twice per lap for how many laps? Much harder then WOT for 12 seconds, shift to neutral and coast 6 or 8 times a night.

Same with my friend's 327 that I just went through. Its a street/strip .060 over LJ 327 (2 bolt onviously) with a 142 blower on it that went 11's. The caps looked just fine.

Like I said before, its good info -- we just need to keep it in perspective.

ps. and it seems that you would agree with me on this. ;)

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Join Date: Oct 2004
Location: NORTHEAST
Posts: 258 Quote:
Originally Posted by Mwilson
Thanks Im running a two bolt block!


The differance is your not running at a 1/2 mile circle track every weekend and if your running at the drags or on the street it would take a long time to duplicate what this engine sees in one nite of racing.
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Which is why I've always wonder why no one on this site ever mentions Roundy-round claimer motors as a viable alternative to the crate motor mix offered for the street. A lot of HD parts for the price. Since no one is actually running them as a claimer in competition you could deep six the smoke stack atmospheric crankcase breathers and go with nice cast ones and PCV, or make any other alteration you want.


Larger Dave

Good point Dave.

I agree with Royce -- circle track has to be about as tough on an engine as you gan get. WOT, then decel, WOT, then decel, twice per lap for how many laps? Much harder then WOT for 12 seconds, shift to neutral and coast 6 or 8 times a night.

Same with my friend's 327 that I just went through. Its a street/strip .060 over LJ 327 (2 bolt onviously) with a 142 blower on it that went 11's. The caps looked just fine.

Like I said before, its good info -- we just need to keep it in perspective.

ps. and it seems that you would agree with me on this. ;)


Eric, you get an "A" on your homework assignment :)