I recently posted a thread here where I asked how many times I could torque down arp bolts. I was asking because I wanted to double check the so-called "machine shop" that did work on my block. Anyways I got some funky readings and decided to take it to a race shop.

Next day the race shop calls me and tells me I need to stop by so they can show me some things. I make my way over to their place after work today and he begins setting up his main bore gauge to show me the first suprise. Well, not really suprise I guess, since I was off on some of my plastigaging. First thing he showed me was the out-of-round area of my mains. In fact, he switched 2 caps to make the tolerances better but they were still off 2 thousandths of where they should be. This isn't a real problem because they can align bore it to correct the tolerance issues with the main bearings. The next and last thing he needed to show me was the main caps themselves. The only main cap that actually "fit" right into the block saddle/grooves, whatever you wish to call it, was the first main - it was tight and I couldn't pound it in with my hand. All the other mains you can take and set into the block, move them back/forth and simulate a twisting motion on the crank. This is no good because you can't get an accurate align bore done with loose slutty mains that will move, twist, and torque while on the machine.

I'm pretty pissed off because the guy I bought the block from (who works at first machine shop I took it to that clearly doesn't know what tolerances for a SBC are) told me the block is good and doesn't need to be align bored. They have a gauge to measure these things, maybe they forgot how to put it together the day my block was in the shop? Secondly, in no way are the main caps fitting correctly. The race shop said it's a combination of wear on both the block and the caps. I the first shop for a "test assembly" which apparently consisted of setting the crank in the mains and turning it. You would think he'd at least see the mains were loose *** in this "test assembly".

Not sure what the resolution to this is. I'm definately calling the guy I bought the block from since he actually works at the machine shop and ask him why he sold me a block with loose mains and told me everything was fine. Then I'm talking to the actual guy that did the work to my block. I plan on asking him if loose main caps are usually a green light to go ahead and build the engine (Before I gauged the block I called him and said what I was doing. He said you can do that or just assemble it, it's fine). The race shop that now has all my parts said they might be able to fix it in house with a real bubba way of doing things. This doesn't really interest me. For those wondering out of curiousity, he said maybe hitting the main area outside the cap seat with a chisle might tighten things up for a while, but the way he said it tells me it ain't right to do. He's going to call another shop that's based in Houston and get an opinion on the situation. I was sort of hoping the material could be built up some way then finished down to where it needs to be given the cap dimensions; this would probably be expensive though.

To make a long crappy post longer, my engine that I've been building toward for a year now is probably going to be a waste. I have no idea how I feel in relation to if the guy I bought the block from ripped me off or is seriously just a dumb ***. He has been at that shop for a looong time. I wanted to take the 400 to the race shop that did my 355 6 years ago, but I thought I'd give the other shop business since that guy works there. For letting them have my business I get all these parts I might not be able to use unless I find another good 400ci block (hard to come by), lied to, and a little over $700 invested in machine work.

 

Sorry to hear of your misfortunes, at least you were smart enough to get it inspected with the proper measuring tools before you put ypour new parts in it and it blew up

See if you can get your money back from the first shop. THe race shop should be able to get you a 400 block, put your parts in that and drive away a happy man

 

With the Vette and Muscle car boom, good Chevy std bore 400 cores are becoming rare,..plus 400's can only bored once before they're unuseable for HP apps.

Do you have the pesos for an aftermarket 400 block? Seems I remember Dart had new 400 block in the $1800 range,..might shop around,..see who else is making them.

But I feel your pain. Good luck!

 

You can buy aftermarket 4 bolt caps and have them fit to the block.

JIM

 

 

check with milidon or www.pro-gram.com. to see if there main caps
will fix your problem. phone no for pro-gram is 330-745-1004

 

I'll check into that. I really wanted to use this block as I already have time and money put into it.

 

Hrm, they only offer the center 3 caps? So I would use the same rear main and front cap which are 2 bolt? Am I missing something?

 

IIRC ... Howards cams did offer all 5 caps ... in two different grades.

http://www.howardscams.com/

Also, I have tightened blocks up by using a punch adjacent to cap ... it works fine for me. I was tightening those that had wear and NOT mismatched caps.

I have an extra 400 block available ... I acquired as complete std motor ... of course it won't go back up std ... email if interested ... but I will not crate/palletize it ... cash buyer must inspect & pick up in eastern SC.

 

Ok, thanks for the offer. I'm going to see what happens with this block. I found out today that the shop can fix the main caps, which will then require an align bore. I've also found that the stoodge that sold me the block did not bore the cylinders using a plate. The race shop said they'd strap a plate to it and see if the cylinders distort and let me know. I'm hoping it doesn't need another hone/bore. I already have my pistons and rings ready to go, + that would mean more money. It will cost $250 for an align bore, plus the freight to ship it to Houston, TX because no one in this city is equipped well enough to do the job professionally, + $20 a main cap to fix. Only 3 caps need fixin so hopefully I'll be ok. Will post results.

Thanks for the support and ideas.

Almost forgot - talked to the guy I bought the block from and he "had no idea" the mains were loose. I asked him about the tolerances and he said the guy that did all the work checked that stuff and it was good. He then told me to bring it by so he could check it while I was there. I made it clear I had already had them checked, but he still insisted on me brniging it by. As far as I'm concerned, I'm not taking anything to them anymore not even to "look at." Haven't tried to get money back yet for anything, but if this turns up to be a real upsetter I can probably sell the block back to the guy I bought it from. He's seems to be that dumb.

 

To be honest, I never realized the that caps should be snug on the block. It makes complete sense that if they are not tight the cap may move slightly. Due to clearancing the block for the 3.75" crank, I had mine off about 6 times. Each time I had to tap the caps with a rubber mallet.

 

You may know this already ... but if not ... be advised: usually align hone/align bore raises crank centerline up toward cam ... usually results in requiring a timing set that is 0.005"-0.010" shorter. If it were me, I'd be demanding at least half of what it's gonna cost to get caps & saddles straightened out ... dunno if I'd get $ ... but I'd get something of worth to the seller. G'luck.

 

If the caps are loose they can still be fixed by a good shop apparently, but you definately don't want to bolt something up with loose caps. They will twist while your torque them down and move under a load resulting in a very short engine life. I'm not sure if actually taking them off and putting them on wear them out. The shop seemed to think it was froml high mileage. Maybe he gave me caps from another block, I dunno. I'm just glad I'm only down the cost of machining and the block (which hopefully I can sale back to the guy I bought it from, since he's "not doing all the stuff I'm doing with it.") The cost to find this all out later down the road would have been much more expensive for me.

Well, this block is done for with my needs. Since I already have my SRP forged pistons with a 30 over bore hung on the rods and the cylinders with the plate on them are out of round all over the place from 1-2 thousandths, I'm stuck looking for a new block. He recommended I pick up a "rough bore" bowtie block from GMPP and it can be bored to what I need. Other option is to try and find another 400ci here locally that will work. Driving around costs too much these days. I'm not against it, but gas prices got me tied down.

This had put my estimated build back at least another 6 months. I hate having parts lying around staring at me and calling me names. They drive me insane. I'll have to hide them now. Any other tips are appreciated.

Ryan

 

www.sdpc.com. bowtie sportman block price $1599, 4.117 bore
simeaze can be bored to 4.155, 2.65 400 mains, all five main caps
4 bolt. priority main oiling, two piece rear main seal part # 12480159
any new block you find will have to be bored for your .030 pistons you
may want to sell them buy 4.125 pistons and have the new block honed to fit.

 

If you're gonna shell out some serious $$$ for a new block, why not look in to a motown block? From what I understand, they improved upon the original design of the standard SBC.

 

I'm looking at the bowtie and the motown right now. I found a motown block on ebay for $1799 + free shipping. Either of which I can't afford at this time but still lookin.

I guess I could sell the pistons but I've already installed them on the rods. I'd rather use what I got a get the block bored/honed out to fit the pistons than risk damaging the pistons trying to take those dam spiro locks off.

 

Where did you buy the pistons, do you still have the box they came
in?? The bowtie block has all the features the world or dart blocks
have for a little less money. the world/dart blocks with nodular caps
are generally $1800 the bowtie block $1600. The world/dart will
allow more overbore dart recomends 4.185 max world 4.200 max.

 

I got them from cnc-motorsports.com. I haven't even looked into returning them yet.

 

I have only used summit, jegs, competition products for parts, the only company I have sent stuff back to was Summit, very easy to do no
real questions asked. See if you can send the pistons back to cnc-
motorsports. as a trade for a set of 4.125 pistons. its porobably
going to cost you another $160 dollars to bore a new block for your
.030 pistons, another down side to using them would be thinner
cylinder walls and less chance for future overbores. The bowtie
block only has a recomended 4.155 bore so if you bored it .030
you would be at the limit they recomend, The dart/world blocks
would allow more chance for boring in case something went wrong
and you needed to bore again.

 

If you are worried about messing up the pistons removing the
spiral clips get the race machine shop to do it.