Bought a set of main cap straps - techniques for setup?

Man, I wanted to 4 bolt this block, but wa really running into a big road block finding anyone who would do the machine work.

So, after re-reading about the main cap straps, I bought a set from a nice fella in Iowa, complete with studs.

Anyway, all I know about the straps is that they were made by Mondello for a 429. There are no installation instructions of any kind.

How would you guys suggest to set up the cap for the straps? Machine them flat on top and lay the strap in place?

Greg

IMHO, machining the caps is the wrong way to go. Any material removed from the arch of the caps weakens them. IF you must use straps...machine them to fit the caps.

How thick are the straps?

I do not have exact dimensions. They appear thicker than the diameter of the studs in the pics the guy sent me.

Greg

chuck stevens wrote:IMHO, machining the caps is the wrong way to go. Any material removed from the arch of the caps weakens them. IF you must use straps...machine them to fit the caps.

Chuck,

I thought that the strap material was stronger than the main cap material? I'd hate to negate the strength increase of the strap by machining it . Would spacing the strap away from the cap with hardened washers or the like accomplish the same thing?

gota love google, and craigslist... I hope these work out for ya...

Yeah, man! Sounds like you know a little about this deal.

Anyway, I found the straps totally by accident while I was researching 4 bolt cap conversions.

Greg

Greg_P wrote:Yeah, man! Sounds like you know a little about this deal.

Anyway, I found the straps totally by accident while I was researching 4 bolt cap conversions.

Greg

Greg,

Everyone has opinions about this. Mine is if you washer under the strap, it won't help the cap walk. I also think if the straps are over .625 thick it will help cap walk even if you machine the top of the cap down. And not lose overall strength. Your only taking .300 off at the very top of the arch, even less as you go towards the bolt holes. I would not put washers under the strap. Cut the caps and bolt the straps straight down or just run it like you have in the past. JMHO Try to get some more.

Cap strap [cap strap-on ] will not i.m.o. provide any more clamping force . They could reduce cap bending/deflection . Like blake said....thick and of high grade steel . I aint sure about milling .300" off the caps ...maybe .030" to have all the caps the same ht. I'd assume the 'strap-on' should be installed with a little preload . This is something if/when is productive could/should be made not bought...it'd be easy compared to making main caps .

Greg_P wrote:Yeah, man! Sounds like you know a little about this deal.

Anyway, I found the straps totally by accident while I was researching 4 bolt cap conversions.

Greg

i dont know anything on this subject... but from what I can gather is the cap walk occurring is from the force of up and down pressure.. and theses straps in theory will help prevent the caps from flexing in that direction....in theory.

so washers between the strap and cap would create a void allowing this to continue to happen, thus defeating the purpose of the straps all together.

to be honest I think the whole girdle/strap set-up is just a band aid for the soul... but with you basically sticking with the same combo before and after this set-up will provide a little evidence, and hard facts as to the how effective this design really is...

the guy I got my straps from cracked his block, I would love to see the condition of the main bearings, and have a little more info on the numbers that engine was making and what type of set-up/tune he was using in greater detail. There was a very very minute tell-tale sign of the strap, and cap walking with this set-up from what I can see on the straps, but the are made of tool-steel, and I'm sure the real tell-tale marks were on the softer material of the caps themselves.

Lem Evans wrote:Cap strap [cap strap-on ] will not i.m.o. provide any more clamping force . They could reduce cap bending/deflection . Like blake said....thick and of high grade steel . I aint sure about milling .300" off the caps ...maybe .030" to have all the caps the same ht. I'd assume the 'strap-on' should be installed with a little preload . This is something if/when is productive could/should be made not bought...it'd be easy compared to making main caps .

Charlie, what do you suggest I do to get the straps to work the best? Sounds like washers are out, milling the cap is out....a couple of weeks ago it sounded like the straps were the best thing since sliced bread on here.

All I want to do is buy time, decrease the chances of a cap breaking till I can be like the rest of you high rollers and get a super strong block.

It's not like we're gonna up the program and count on the straps to hold another 100HP or anything.

Greg

greg is in a 4 bolt funk...LOL if milling the caps is out how you gonna use these? I'm just gonna machine the caps, run the straps, and hope for the best until like you an A460 comes when time, moneys, and necessity (850-1000hp) warrants it. on a side not do you think these will have clearance issues with a windage tray? Mine are .626 thick. .300 being removed from the caps and i think the studs are actually longer as well. [img][/img]

1] Do whatever you want to do .
2] I Can't remember offering an opinion about washers .
3] I did not say to not mill the caps...only to do them less than .300" i.m.o.
4] If you want to buy time...run what you got..i.m.o.
5] My name is Lem not Charlie .
6] Are you having a bad day or what ?
7] How do you know how high I roll and what does it matter .
8] I like sliced bread .

9.) Lem does not like 2 bolt band aids.
10.) Lem goes 4 bolt when in doubt.
11.) Lem probably prefers real butter to Vegatable spread also

these are all opinions of course

".) Lem does not like 2 bolt band aids. "
............................................................
Band Aids are ok....effective and cheap is to the point .

Another thread that went to the shitter. All I was asking for is a little help, that's all.

You just did not get the answer you wanted

"If you want to buy time...run what you got..i.m.o."
.............................................................................
I gave you the BEST answer

Umm, do what Lem said.

Greg the 4 bolts are the Best the straps do a better job of holding the cap walk down, than a Girdle... like I said in the past it keeps the center of the main cap from bowing which is what in my opinion causes the cap end to work and fret the block..If you want to use them mill the caps...... is your block .030 now.....?


Randy

Lem Evans wrote:You just did not get the answer you wanted

I think you know me better than that.

I would just follow what Lem said.

Machine the cap flat and put the strap in place, as long as the strap has some beef to it. Is an A460 block a better choice, sure, is this a perfect world, no.

I'm not posting an opinion about cap straps, girdles, factory four bolt versus four bolt splayed, etc. But I do have a question about various methods for locking the caps in place on the block, I've seen locating pins in the block, slots milled in blocks and caps for hard key stock - but has anybody counter sunk the bolt holes in the block and caps to take a circular locator similar to the sleeves that locate our cylinder heads to the block? It seem's to me that a hardened steel sleeve that intersected the bolt holes in the block, and the bolt holes in the caps could / should all but eliminate cap walk. This is just my opinion, so please don't flame me too badly. And, of course - HAPPY NEW YEAR TO ALL OF YOU GUYS (and girls)!!

Wayne (SAWDOFF) Pearce

The photos earlier in this thread are exactly what is to be done IF straps are to be used. The ensuing laminated package makes resistance to cap bending and cracking much greater.
Alloy studs if torqued correctly will have greater clamping force than bolts.

As stated elsewhere, the block itself, at the main webbing, will now become the weak link.

Dowels will keep the caps from walking however, will NOT stop fretting from bouncing due to excessive instantanius pressure as occures with detonation or ill tuned nitrous.