How many use a girdle??

[trularin]

Okay girls...how many of you use a stud girdle or a main journal/cap girdle on your engines?

I am thinking a main journal or cap girdle would be good for an FE.

Post what you have.

[DougD]

Not needed for a 427 - that's what those funny cross bolts are for.

[DAVID GAGNARD]

I use one on my small block race motor, but a top engine builder told me the main thing it does is hold all the peices together when the motor blows up.....

David

[Gordon Levy]

David has that correct.

[DAVID GAGNARD]

David has that correct.
__________________

Gordon;

In simple terms (I'm no engineer) WHY????? It seems to me it could only help the bottom end, but actually more than one respected engine builder says they generally are not worth the money, that they do not do that much good...... I bought the girdle adding it to a standard production 1969 302 block....the motor is a 331 stroker putting out 472 hp @ 6400rpm, and 441 ftlbs torque at 5500rpms..... I thought it would be good "insurance" against bottom end failures.

The motor is in a 65 Coupe road race car and on track normally runs between 3500 and 6500 rpms, races usually last 20 minutes....So far NO failures of any kind, everything in the bottom end is forged and top qualilty parts....the motor is out right now to be freshened up, has somewhere between 40 and 50 running hours on it..also, making a change in the cylinder heads and should be right at 500 hp and 475 on the torque.....

Thanks;

David

[Poolw]

While reading through my new Summit Racing catalog last night, I saw gridles and was think about looking into to installing a pair of girdles on my motor, but with all the great info posted here. I'll spend my $200 on something more beneficial - like gas.

[Gordon Levy]

According to 2 engineers that are friends, it really doesn't make the block stronger. What is does do is keeps the main caps from walking to a point. This will help with longevity but not actual strength. There are also different types available. The aluminum ones don't do anything, as well as most of the mild steel ones. The only one that My engineer liked was one that is made out of 5/8" tool steel.
Most people make the mistake of adding a girdle to an already machined engine. This is very wrong. The machinework must be done with the girdle in place. That 5/8" tool steel girdle will distort the block. That is also a $400 girdle.
Using block fill and the girdle will make the block stronger but it is a bandaid at best.
Adding up the costs of doing it this way or buying a good block is about $800 difference. Not much when concidering you probably have $7k-$12k, (average for a small block), tied up in your engine.

[Excaliber]

Very interesting advice on the girdle question, thanks for weighing in Gordon.

"Hold the pieces together when the motor blows up."

[DAVID GAGNARD]

o-k, I see the reasoning behind that......when it is time for the next "freshening" which should be about this time next year, I intend on going with an aftermarket 4-bolt main block...I had originally planned to do just that this time, but time and unexpected other expences kept me from doing it...

I've seen the nice shiny new aluminum girdles and wondered how they could be of any use.....

The girdle I have is a nice machined piece, kinda heavy I thought when I picked it up...I did have the machine shop install it and torque plates when the machine work was done on my block, so I guess I did the right thing for once...

Also was told that a OEM production 302 block like mine should safely take 425hp, much beyound that, the block will tend to crack/brake under pressure of high rpms in the upper webbing of the crank journals....to the naked eye, that looks like it very well could be a weak point...

A number of guys I race with use the different aftermarket 4-bolt blocks (302 to 347 cu in) and most make more hp than my motor, one in particular is making about 120hp more than my current motor, he has been running that block for 5 or 6 seasons now with no problems,on the other hand a number of guys with OEM are getting 2 maybe 3 seasons out of their blocks...
Thanks for the reply Gordon.

"Hold the pieces together when the motor blows up."

Ex; if you've ever seen the bottom end of an engine after a "catastrophic" engine failure, you'll know what I mean.over the years, I've seen the weidest things happen to piston,rods, camshafts, crankshaftsand cylinder heads after an engine lets go, most I did not believe until I saw the results myself.... the best one was a smalblock chevy dirt track motor, they forgot to torque the rod bolts down, one rod looked just like a pretzel!!!!!!!!!

David

[Hal Copple]

When Bob Olthoff built my motor, a stroked 392 Windsor, and i asked about a stud girdle, he assured me it was not necessary, and over a hundred K hard miles later, he was right.

all the best...

[BDR561]

Same view for a rocker girdle?

[blykins]

Keep the horsepower around 500, make sure the reciprocating assembly is well balanced, and use main studs. You should be fine.

I've heard KC and some of the others say that the blocks want to split between the mains and cam bearings with over 600hp and high revs.

BTW, didn't you say you had a 406? I thought the 406 blocks were cross bolted.

[rdorman]

Dave, my underwear is none of your business.

[rdorman]

Originally Posted by BDR561

Same view for a rocker girdle?

No, but not every engine needs them. Even high performance ones and very rarely ever a motor that can be driven on the street (I have seen 900 HP motors work just fine with out them). But, if you feel so compelled, won't hurt anything either... except of course it can be a pain when you adjust the valves. Shaft is the latest trend for really high lifts and spring rates. Best thing you can do for your valve train is to make sure that the geometry is perfect and that all the components where designed to work together.

[will butterwort]

set up, but I really don,t see the need for such----scat crank and probe rotating system, southern automotive bolted up ,did crank alignment honing, looks impressive, but don,t really think it does all that much.Two engineer son,s wanted to do it, so i bet there is something that has to do with something here that my education level comes short of.Will-alabama

[wtm442]

Originally Posted by rdorman

Dave, my underwear is none of your business.

If I gain any more weight, I may have to get one.

[BDR561]

Here's a pic of my 410 during assembly with its girdles attached...

[IMG][/IMG]

[rdorman]

I tend to compeltely agree that the average off the shelf main girdle does little more then help hold stuff 'together' once it fails.

I do however see times where a PROPERLY engineered and installed girdle can be of help when you have no choice such as in classes where the output tends to cause cracking in the webs around the main bolts but you are forced to use a stock block. Bottom line is trying to locate the cap. Tolerences are too large on mass produced engines and OEM materials are not up to the job. Aside from good 'shouldered' or doweled studs (machining required), caps of sufficient strength (both can help the block), more 'bolts' and splaying, I can see where and FE can benefit. They are know to crack when pushed above 600HP or so (I am sure many of done it with out failure so no need to let me know! ). What the FE has going for it is the skirts. Just like they crossbolted the 427 to help, a proper girdle can tie the caps too the skirt, but in all directions. Like was said earlier, it doesn't make the block stronger, just likely to live longer by reducing cap walk or fretting (just like our motors don't suck air in, atmospheric pressure forces it in). Pull a cap and it is easy to see if it is walking on you by looking at the mating surface. Be sure and listen to the point about it all must be machined to work together or you will be sorry!

But then again, I am not an engine builder

[DAVID GAGNARD]

I have a rocker girdle on my race motor, mainly cause a fellow racer gave me his when he went to shaft mounted rocker arms...... On a race motor it should be of some help, on a street motor it is probably overkill.......

My race motor has a solid lifter roller cam in it and in 2 race seasons I checked the valves once and only had to adjust about 1/3 of them........I took particular care and time when building this motor, valve train geometry was checked and double checked all along the way and studs were used on the crankshaft mains and heads....all top quality parts and peices went into this motor and it has been super reliable for two race seasons........

You can't go wrong using top quality forged parts and checking all clearances and making sure everything is installed correctly.......

David

[Gordon Levy]

Rocker girdles to help reduce some deflection aspecially if you are using 3/8" studs. 7/16" stud generally don't need a girdle unless you use turning over 8000 revs repeatedly. Engines that turn that many revs we use shaft rockers.
I like to see a freshen done on an engine after 25hrs of track time.
Then we tend to turn ours 8-9000 revs on a regular basis at the track.

High quality engine parts are a requirement for longevity if you plan on running it hard. With engine parts, You get what you pay for.