machine block for a girdle?

[1of1035]

I'm going to put in a RJC girdle and mains. I think I heard somewhere the block has to machined for it. So if it does what exactly has to be done?

[KendallF]

I'm going to put in a RJC girdle and mains. I think I heard somewhere the block has to machined for it. So if it does what exactly has to be done?

If you are just doing the girdle, the caps must be machined flat to a specified height. Then the girdle's preload is set with shims and the block is align honed.

If you're doing steel caps and a girdle, the caps must be fitted to their registers, machined flat on top again, the girdle fitted, and an align bore and hone done.

[1of1035]

Thanks for the info. Not what I was hoping to hear but looks like I gotta spend more money. I guess its better to spend a little more now than alot more later. Any idea how much this will cost?

[KendallF]

Thanks for the info. Not what I was hoping to hear but looks like I gotta spend more money. I guess its better to spend a little more now than alot more later. Any idea how much this will cost?

I forgot to mention earlier..the back cap has spacers that must be tack welded on before it's machined flat. Jason Cramer (RJC) will do this and machine the caps flat for a nominal fee ($60, I think?). The hone price will depend on whether the shop has done one of these before and realizes what a pain in the ass they are. :D I would count on spending a minimum of $200 to get the girdle preload set properly and the hone done. I did one recently and I paid $150 for the hone, but I did all of the other machine work and helped set up the align hone as well.

[1of1035]

Thanks. Now i know where I'm going with this part at least.

[jastrckl]

hey kendall, say you had some steel caps and the align hone done earlier, and wanted to add the girdle at some later date. Would just levelling off the caps to provide an even surface for the girdle be enough, or do you figure it'd have to be align honed again?

[KendallF]

hey kendall, say you had some steel caps and the align hone done earlier, and wanted to add the girdle at some later date. Would just levelling off the caps to provide an even surface for the girdle be enough, or do you figure it'd have to be align honed again?

In my opinion, you'd need to redo the hone. The girdle pushes down on the middle of the caps and loads them differently which will change their shape. I know some people have put the girdle on without doing a hone; IMO it's a gamble.

Oh...for what it's worth, I told Ekool I vote to reinstate you in #buickgn as a reward for the redhead pix. :fly:

[turbo buicks]

which is the betr choice, girdle or mains? i say girdle. how important are the mains if you have a girdle? are the mains just "added security" or are they a common part to fail? and if they are good to get should it get all 4 or whatever or just the front and middle 2?

[shoebox]

If you have a billet or steel crank, 4 mains will do. If you have a stock crank, a girdle is a plus, although it is just a band aid. I would rather have billet mains myself over a girdle, since you are more likely to crack a stock cap, then have actual "cap walk". Even if you have a girdle, chances are if there is any unwanted "play" in the crank, you will still damage a cap.

[KendallF]

If you have a billet or steel crank, 4 mains will do. If you have a stock crank, a girdle is a plus, although it is just a band aid. I would rather have billet mains myself over a girdle, since you are more likely to crack a stock cap, then have actual "cap walk". Even if you have a girdle, chances are if there is any unwanted "play" in the crank, you will still damage a cap.

I disagree..rather emphatically, in fact. I have seen a number of blocks cracked in the webbing above the caps. There's just not enough meat there to hold them in. The girdle spreads the load across the pan rails; there's no doubt it's stronger. I would prefer a girdle and stock caps to the steel caps alone. It's still a toss-up in my mind whether a billet crank makes it better or worse regarding cap stress..it may flex less but it's heavier.

[shoebox]

I disagree..rather emphatically, in fact. I have seen a number of blocks cracked in the webbing above the caps. There's just not enough meat there to hold them in. The girdle spreads the load across the pan rails; there's no doubt it's stronger. I would prefer a girdle and stock caps to the steel caps alone. It's still a toss-up in my mind whether a billet crank makes it better or worse regarding cap stress..it may flex less but it's heavier.

I agree with the theory behind the girdle, however I have seen stock block cars at tsm power levels hang together without steel/billet caps or a girdle. Or cars with just caps(usually 2 center mains) and a stock crank do fine also. I guess it just depends on how lucky you are and if the tune is right.

For arguement sake, I believe the fastest TSM car in the land has four billet caps, a steel crank, and no girdle. Then if you look at the second fastest TSM car, it has a girdle, 4 caps, but it has a stock crank.

Different strokes for different folks. :arco:

[Quickt]

I like the girdle much better myself. After seeing Bamford this year at Reynolds I am starting to wonder if the crank and caps might be all you need.

[2 qk 4 u]

Ok...I'm in the process of building a shortblock. This is what I'm doing.

Stock caps

RJC Girdle Kit

Stock Crank

Stock rods w/ArP bolts

TRW F/M Forged Pistons w/lightweight pins

208/208 Camshaft

HiVol Front cover

dbl roller timing set

Stock balancer

Stock flexplate

RJC aluminum pulleys

I'm wanting an 11 second street car, so I'm building the foundation for a 10 second engine. Take it easy on it.....yeah right huh.

[lazaris]

Billy Anderson has always said the caps work as well as a girdle if done correctly. Im sure both methods work well.

[EightSecV6]

I personally use only the caps on our stock block stuff for several reasons, these are strictly my opinions, if you dont agree, then you dont agree....
1. They leak
2. You can put alot of silicone on them to keep them from leaking with the possibility of the pickup ingesting it.
3. Very difficult to remove the pan for inspection etc
4. it adds weight.
5. I have had very good luck with the caps

They (girdles)obviously work well as guys are using them and reliably running fast.

[Scott Atk]

I've had great luck with my mid 10 sec. car using two center billet caps only. I was thinking about building a production 4.1 next. I think I read somewhere that the 4.1 blocks are weaker so possibly a girdle for those would be considered mandatory at 10 sec. power levels????

[gasketmaster]

I personally use only the caps on our stock block stuff for several reasons, these are strictly my opinions, if you dont agree, then you dont agree....
1. They leak
2. You can put alot of silicone on them to keep them from leaking with the possibility of the pickup ingesting it.
3. Very difficult to remove the pan for inspection etc
4. it adds weight.
5. I have had very good luck with the caps

They (girdles)obviously work well as guys are using them and reliably running fast.

Hey Bill,
Do you think the fact that most steel crank motors usually get internally balanced weighs into the reliability factor?
Most of the more budget buildups using the girdle have stock externally balanced crankshafts.Maybe they are less happy spinning 6000-6300 rpm.
I've only seen one engine with steel caps and an internally balanced stock cast crank.It made big power and lasted a long time without driving over the crank :zahn:

Just curious :)

[Race Jace]

I like the girdle much better myself. After seeing Bamford this year at Reynolds I am starting to wonder if the crank and caps might be all you need.

Since then they have taken the motor apart and both the steel mains and the block are junk. so much for that theory.

To my knowledge no one has ever broken a stock cap after a girdle has been installed. Simply, the caps don't carry enough load to make them fail. The girdle does more than just strengthen the caps. It increases the block structure as a whole, supports the main webbing, cylinders stay more round, it keeps the main bores lined up and helps keep the crank from flexing as much.

caps just keep the caps from breaking. (without a girdle) and the steel crank keeps the crank from flexing, that is it.

hope this helps.

Jason Cramer
WWW.RJCRacing.com

[REDS TTYPE]

my view on it is stock caps and girdle machined properly and the bottom end will be the last thing to break

to me the girdle not only strethens the bottom end up but also acts as a safety feature if or when a crank does snap it will keep it contained in the block verses driving over the crank and conveter at 130+ mph :eclipsee:

[gnx7]

So everyone agrees that the stock crank flexes in the center under high boost conditions. If you run the engine hard all the time the #2/#3 main bearings are going to sooner or later get worn down and oil pressure will get worse due to crank flex. Billet caps worked fine with no problems in a friends mid 10 second car (200 passes+.... mainly low 11's high 10's with probably 40 passes in the low 10's) and before the time of the girdle back in the 90's.

I think if you are really going to push the car hard all the time the girdle is better. More work and PITA to install for the machine shop.... but it does make more sense about spreading load and tying weak points together to form a better foundation.

Both billet caps and billet girdle need a line bore/hone..... so the real difference is only about $200 in parts and the inability to easily pull caps after a season of racing to view the bearings for wear.

Like Jason said.... no block failures yet with girdle.

-GNX7

[top gun]

Since then they have taken the motor apart and both the steel mains and the block are junk. so much for that theory.


Jason Cramer
WWW.RJCRacing.com


Wow! not sure where that info came from, last time I saw the motor everything looked good, caps and motor were still intact. If It was falling apart I don't think it would have run a string of 9.50 and 9.60 passes at Reynolds. Last word from Dan he is waiting on the heads, it is on the stand going back together with the same parts caps and all!

[Turbobuick]

So everyone agrees that the stock crank flexes in the center under high boost conditions. If you run the engine hard all the time the #2/#3 main bearings are going to sooner or later get worn down and oil pressure will get worse due to crank flex. Billet caps worked fine with no problems in a friends mid 10 second car (200 passes+.... mainly low 11's high 10's with probably 40 passes in the low 10's) and before the time of the girdle back in the 90's.
-GNX7

I've had some experience with this. The crank flex definetly what breaks the block and caps. I'm fairly certian that steel cranks will still flex they just won't break as easily and don't flex as much. We had my engine (109 steel cap girdled block with a steel crank) apart and a friends (4.1 Stage 1 with caps and steel crank) at the same time. Both motors were making around the same power (mid 10's) at the time and had about the same amount of run time. When we looked at the center caps on the S1 he had cap walk, mine had none and it was that obvious. Needless to say his S1 went back together with a girdle. I agree with Bill though the girdles can be a PIA.
Chris Lyons

[Race Jace]

Wow! not sure where that info came from, last time I saw the motor everything looked good, caps and motor were still intact. If It was falling apart I don't think it would have run a string of 9.50 and 9.60 passes at Reynolds. Last word from Dan he is waiting on the heads, it is on the stand going back together with the same parts caps and all!

are you kidding me? you would not believe how many people told me what i stated. I guess you never know what or who to believe anymore.

Why didn't you have your car at Bradenton? I was all excited to hear about the match race between you, Roy and that 9.30 @ 148 TSM car that i also heard rumor of. :arco:

[Scott231]

To add another experience based note - Many of you have seen the pictures of the carnage that happened to my stock internals, girdled, steel capped 109 motor upon explosion on the dyno back in Sept 2003. Although the crank snapped into 3 pieces, two pistons became nothing but schrapnel, I bent up two rods, and the girdle was bent out of shape - the block and caps are being reused. After a few tests, those pieces checked out just fine. :SHOCKED:

Now if that explosion had occured without a girdle, I would have lost everything, including some body parts. And if that had occured on a dragstrip without the girdle... :kater:

[Turbo Archie]

I would find that hard to believe if it wasn't coming from you.