Share thoughts on B block girddle

[MOPLUM]

First I am a experienced retired engine mechanic. (Gas turbine and diesel proffesionaly. Cars, antique tractors as a hobby). So I am building my dream 1970 Road Runner for myself. I want a true hotrodded Road Runner. Most Road Runners came with B block 383, so I am building a stroked B block. Using Muscle Motors 489 kit for the bottom, and Indy cylinder head for the top end. Now to the point: I bought a main stud girdle because I am building this for nitrous. I have never had a problem with any MOPAR big block strength in the past, but thought this would be good insurance. I have pulled the oil pan now five times due to severe oil leaks at the rear of the pan. I have never had this problem. Never had rear main oil leak or pan gasket leak after repair. This was BAD. I used two Kieth Black rubber metal pan gaskets, red silicone betweem girddle and the block. MOPAR stroker windage tray, Indy seal retainer viton oil seal. (The seal or retainer never leaked). I have a 60 ton hydraulic press for straightening steel. I straightened the girdle arrow straight. Shimmed it so it was perfect flat between main cap and the block. Everytime I pulled and inspected I found only at the rear of the engine. The silicone blown from between the girdle and block. Oil pushed through the pan gasket and girdle. The pan to include the seal retainer has studs not bolts with football shaped washers to spread nut compression pressure against the oil pan.

So this is what I found to be the problem: the rear of the girdle that covers the rear seal retainer is very wide. It is holding oil so much it is blowing between the pan and the girdle. I have finaly decided I am leaving the girdle off. I may someday cut all that excess material off, or drill drainage holes, But five times is enough. I hope this help anyone else installing a big block girdle.

 

[lewtot184]

to me girdles on a y-block are dumb. the blocks should be cross bolted with steel caps but that requires thinking and no machine shop wants to do that.

 

[MOPLUM]

Lewtot184: I totally agree. If this block fails (I doupt it will) but if it does I'll go with an after market RB or Hemi with cross bolted mains. Like I said in my original post, I have never had a problem with a big block strenghth. Here I go with an opinion that Im sure will be debated: Big block failures are usually from exceeding RPM limit. Missing shift, showing off, ect. B blocks can endure a little higher RPM than an RB due to a shorter stroke (Unless stroked). But 6000 RPM is as high as "I" feel safe taking a big block. The current engine build in my Road Runner peeks its power band around 5000 with hp and torque. Of course I can play with that with different octanes, timing, cams, EFI, intake manifolds, heads, ect. Power and torque may go up and down but I like 5000 for the RPM range for peak. If I want higher RPM small block is the way to go. (75,000 to 78,000 RPM Chrysler gas turbine would be cool too).

I have never used nitrous so I was a little concerned. But the girdle is not the answer at this point. 1: I dont have to use nitrous, 2: if the block fails, I will do like you and I said and get one with cross bolted mains. This is not for professional racing, just a good strong street, and ocasional track build.

 

[badlite]

Dvorac in Fla does cross bolt mains

 

[cryplydog]

Can you tell us what brand or whose girdle you used?

 

[moparcrazy]

Wow that's some pretty tough stuff ! Hers a Link...

http://www.dvorakmachine.com/4boltconversion.shtml

Dvorac in Fla does cross bolt mains

 

[MOPLUM]

MOPARcrazy that is a great looking cross bolt kit, I may do that. Looks better than others I have seen. I'm sure California has a good variety of MOPAR savvy machine shops to work with. Here in Alaska I have only a few. They work on 99.9% Chevy & Fords. Boring, honing, clearanceing and other common machining I like my machine shop I use, but hessitate with cross bolt main upgrades that I have seen previous to this kit. Old good seasoned B blocks are hard to come by up here as well. That is why I chose a girdle, but all is good.

 

[MOPLUM]

Cryplydog: I bought it from Chenoweth Speed and Machine, P/N: CREGK375, $450 plus shipping.

 

[MOPLUM]

Removed girdle, reinstalled windage tray and oil pan. Reused Kieth Black oil pan gaskets. No leak, dry as a bone!
NOTE: the girdle may be fine as is in a non-modified engine? My oil passeges were enlarged to the crankshaft and rocker oil feed. High volume pump. Full fillet Callies crankshaft with .0025 oil clearnce on the rear main. I am sure I have more oil off the main than a stock engine. With the girdle covering the main cap and rear seal retainer it can't return oil away from the rear of the engine fast enough, forcing excess oil to push through the rear gasket, between the girdle, and seal retainer.

I will remove that wide area of the girdle so it is the same width of the oil pan gasket if I decide to use it later sometime. That will eliminate excess oil buildup at the rear of the oil pan. Again I hope my posting this may help someone else that has oil leak problems using a big block girdle.