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Stud, Girdle, or Nothing?

So, you fill the block almost all the way to the deck, and this works well for street driving? I'm looking to rebuild a '94 6.5 soon and want to do anything extra I can to make a good, strong, longlasting engine.

Thanks,

Bill
 
I think filling the block is only good for race use. If I am correct when you fill the block you are taking away from water cooling ports. Which you would not want to do for a daily driver/trailer puller. I could be wrong. Please correct me if I am! If I am then were else do they find the space for the filler. It aint like they have lots of extra room down their.

Just my 02 cents!
 
DieselCash said:
I think filling the block is only good for race use. If I am correct when you fill the block you are taking away from water cooling ports. Which you would not want to do for a daily driver/trailer puller. I could be wrong. Please correct me if I am! If I am then were else do they find the space for the filler. It aint like they have lots of extra room down their.

Just my 02 cents!
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6265 racer said:
We build engines only for our own use. We fill the coolant passages of every engine we build and have done so for many years. These are filled to a depth, which still allows room between the concrete and the under-deck, so as to allow distribution of coolant from the upper block into the heads. The Suburban we use to tow the land speed truck is one of many done this way. We use our Extra H-D cooling system upgrade on every one of our trucks and Subs. For those unfamiliar with it, the 750 mile trip from our facilities to the salt flats is mountains all the way and we never see more than 1 notch below the 210* on the gauge.
Click to expand...

They build all their engines this way, even street driven.
 
6265 racer said:
I missed a couple of questions---sorry. We use the regular 6.2--6.5 ARP head stud kit part number #130-4062. The main studs we use are unique to this application and we are working with ARP to make this a Heath part or at least a regular ARP offering. We prefer the older blocks with 12mm studs in all 10 locations and this is what this set will fit. The newer block with its smaller 10mm holes on the outer of the center 3 will need a different combo of inner and outer. For what it is worth, we think it better to stick with the factory fasteners on these newer blocks than it is to do studs in the outer of the 3 center mains. Better would be studs everywhere----but never studs on those outer locations of the center 3 mains.
Scat's Bob Jones says the Scat 6.5 crank is a factory balance set up, so, just like the factory did it, you can throw it in without doing anything. We like to balance everything.

<snippage>
Click to expand...

Oh no. Now I'm really mixed up. Why not 10mm studs in the outer holes? What about a mix of studs at the 12mm holes and bolts in the 10mm holes? What about the DSG girdle? Is it simply a waste of money or is it worse to install it? ...or might it actually be beneficial? This is a GEP 2003 block if that makes any difference.

The whole reason I started on this quest for studs was the torque specs on the 12mm mains, 55-55-add 90 degrees, just like the TTY head bolts. The 10mm bolts just get something like 35 ft-lbs if I recall correctly. Is that not enough for studs?

I could certainly use the $300+ it will cost for studs for the bottom of this thing. ...and $160 or so for the girdle. OTOH, the engine work has come to quite a bit less that I anticipated, so I do have the fundage. I'm trying to do this right. I bit the bullet and spent the $$$$$ for the Fluidampr, and had the shop balance the reciprocating assembly (with the OEM balancer).

Missy G, feel free to hop back in here.
 
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We will lay the cracked block asside everytime, saving it for more difficult times as we search for that which is not cracked. The engine in our 1995 racer is the original unit. The original owner had racked up 288,000 miles without having put a wrench on it and it still ran great. We were thrilled to find that it had seasoned well and with no cracks, because, for us, there is some certain value in it being the original.
We feel that using studs and or girdle on the outer positions of the middle three mains is always a mistake, as this causes loads in the block casting for which it was not designed. Use factory bolts or stud the whole shebang. We avoid the later blocks with their 10mm outer bolts. When these break out of the #4 main web and up into cyls 6&8, it is interesting to see how they don't just crack-----they literally open up and the parts twist and pull away from one another, in clear demonstration of some significant stresses in the casting and we have seen a fair number of them break in this same way. Perhaps we've seen only the crappy ones, but each one of these we have checked, has a crooked main line. Their housing bore diameters are inconsistent and the cap register deck areas are uneven. Don't see how it can help but to break. GEP claims to have rounded the corner, that this nonsense is a thing of the past, that quality of machine work is dramatically improved. Guess I have time to wait and see----so long as there are a few remaining, uncracked, old style blocks lying about.
I like the idea of the piston cooling nozzles, but when it has to be part of a block that falls apart---I think it is better to go old-style, coat the pistons and keep the EGT at or below about 1050*-1100*.
Maybe someone out there has a way to make the later block reliable in the more highly stressed applications.
We have considered baking one of these at about 450* for 10-12 hours to help relax the casting. The baking would be followed by a thorough peening of all external surfaces with a good sized ballpeen hammer and remachining of the main cap register areas and mainline bore, before the block is fitted with studs and loaded with mud.
After the block fill is cured for 45-60 days, we would go ahead with bore work then cross our fingers, sprinkle a white rat with bat urine and see how the thing holds up-------might be worth a try.
 
Thanks Bill, Got some more for ya:

Is it ok to re-use rod bolts on the 6.5s?

What do you like to do to seal up- Oil pan, timing cover, valve covers- Use gaskets- or no gaskets and just use ultra black RTV or General Motors brand sealant?

Any tips on 6.5 engine assembly? Thanks for sharing, Dave
 
[
After the block fill is cured for 45-60 days, we would go ahead with bore work then cross our fingers, sprinkle a white rat with bat urine and see how the thing holds up-------might be worth a try.[/QUOTE]

I am still laughing, I would try anything if I thought it would help. I am having a hard time finding the white rat though. ):h
 
6265 racer said:
We will lay the cracked block asside everytime, saving it for more difficult times as we search for that which is not cracked. The engine in our 1995 racer is the original unit. The original owner had racked up 288,000 miles without having put a wrench on it and it still ran great. We were thrilled to find that it had seasoned well and with no cracks, because, for us, there is some certain value in it being the original.
We feel that using studs and or girdle on the outer positions of the middle three mains is always a mistake, as this causes loads in the block casting for which it was not designed. Use factory bolts or stud the whole shebang. We avoid the later blocks with their 10mm outer bolts. When these break out of the #4 main web and up into cyls 6&8, it is interesting to see how they don't just crack-----they literally open up and the parts twist and pull away from one another, in clear demonstration of some significant stresses in the casting and we have seen a fair number of them break in this same way. Perhaps we've seen only the crappy ones, but each one of these we have checked, has a crooked main line. Their housing bore diameters are inconsistent and the cap register deck areas are uneven. Don't see how it can help but to break. GEP claims to have rounded the corner, that this nonsense is a thing of the past, that quality of machine work is dramatically improved. Guess I have time to wait and see----so long as there are a few remaining, uncracked, old style blocks lying about.
I like the idea of the piston cooling nozzles, but when it has to be part of a block that falls apart---I think it is better to go old-style, coat the pistons and keep the EGT at or below about 1050*-1100*.
Maybe someone out there has a way to make the later block reliable in the more highly stressed applications.
We have considered baking one of these at about 450* for 10-12 hours to help relax the casting. The baking would be followed by a thorough peening of all external surfaces with a good sized ballpeen hammer and remachining of the main cap register areas and mainline bore, before the block is fitted with studs and loaded with mud.
After the block fill is cured for 45-60 days, we would go ahead with bore work then cross our fingers, sprinkle a white rat with bat urine and see how the thing holds up-------might be worth a try.
Click to expand...

Wow, there's nothing like getting your Wheaties peed in. :sad:

The way my main and rod bearings looked, there was something out of square between the crank and the cylinders, but most all the rod bearings plastigauged okay -- two were .001 too big. I didn't check the mains. Is this "crooked main line" something that gets fixed with an align hone? Would a good shop find mismatched mating main mating surfaces when they do the hone?

If the main caps were assembled with studs and girdle, then align honed, does that make things any better? How about with just studs?

This engine had cracked heads; I had to buy two new ones. The bearings looked like hell, yet there were no cracks in the block. I think this thing was overheated on more than one occasion. I'm grasping for good news here... Is there any?
 
Bill, et all; Be advised - The white rat bit only works on a full moon! Otherwise you get bad juju instead of good.

On a more serious note - Which harmonic balancer do you use on your engines?
 
To make sure we are all on the same song sheet, the areas we are referring to are those 10 places that the 5 main caps mount onto. The problem we often see with these is that they are not square with one another front to rear or from side to side for any given cap---they are out of square and parrallel. So, when a main cap is fastened onto any pair of these less than square mount areas, there is an unusual and often unreasonable 'load' placed on both the cap and the block. We think this happens when the block is not well seasoned or cured before going through the machining process. Couple the goofy loads or stresses with the excessively large holes drilled in the main web for mounting the piston squirt nozzles and bingo----the casting, in its effort to unwind, may break.
Universally, when we find an unbroken, high mileage block, it will have acceptable to very good main cap register decks.
Your machine shop person, can check the 'squareness' of the cap register decks with his machinists straight edge, feeler gauge and a good eye / feel. My guy sets the block in a big Bridgeport-like machine and moves it side to side as he looks at these surfaces with a dial indicator.
If it checks out or even if it needs a minor cut to make it true, we do that and then bore and hone the mainline.

Even on a block that is not cracked, if we happen to find that the cap registers are out of whack, beyond what we are comfortable with, we will go back to the core pile looking for one that more closely suits our needs---assuming we have this option. When there are no options, we will invest in having these mount areas corrected and the mainline bored and honed. If it makes 50-80,000 miles----it should be ok.

Maybe we are chicken-hearted, but we always replace rod bolts with new GM pieces. Our machine shop guy inspects the rods for any flaws then gives them back to us for a little trip through the oven. With the bolts and bushings removed, we bake the rods and caps for 10 or so hours at 430-450*. Then, after these are a little more relaxed, our guy machines them to the low side of the dimension range (housingbore) and fits new GM bushings which are finish-bored to correct the center to center dimension.
We have yet to find a new GM rod we would go directly to the engine with, if that engine is going to see a rigorous life.

Our engines are glued together with Permatex 599BR. We use no oil pan or valve cover gaskets----just the 599. The exception to this practice is on our race truck engine which is assembled with valve cover gaskets, but that is only because we need to be able to get it apart often for inspections. This 599 stuff practically welds the pan and v/c's onto the engine----you will practically have to destroy these in getting them off the engine. However, if you have done your job well, it will not need to come apart for 250-300,000 miles---so who cares so long as it is bone dry.
We DO use a gasket on either side of the timing cover casting. GM built the engines with only a glue between the timing cover housing and the block. We prefer to put a fel-pro gasket in there with the 599 for good measure.
We always install a new turbo drain tube connector hose. The dealer has this little gem and it is the only one to use.

We use the Fluidamper deal to control torsional activity, even though Scat doesn't like them. If we ever break a shaft, we might reconsider, but for now we feel ok about this arrangement----ignorance is bliss.

Well, my wife is back in town today, so I will likely not be out to play again for a while. It has been fun for me and I look forward to seeing you again.

I certainly appreciate your interest in our racer. Sharing what we do is always fun for me. Feel free to call me with any questions or comments----I always enjoy our tely visits.

Bill
 
We avoid the later blocks with their 10mm outer bolts. When these break out of the #4 main web and up into cyls 6&8, it is interesting to see how they don't just crack-----they literally open up and the parts twist and pull away from one another, in clear demonstration of some significant stresses in the casting and we have seen a fair number of them break in this same way.

I am wondering if this applies to the late 90's blocks? My sig truck has been bullet proof so far, just wondering what the oppinions are on these vs. the older ones. Any thought? How can I find out what vintage of block it is?
 
I drove 50 miles to take my engine to a recommended shop. 500 miles to Washington was outta the question.

Bill, I think you should move your shop to Utah -- just for me. I'm building this thing with the intention of leaving it stock, but trying to beef it up in case I need one of your towing flashes.

...been great having you here spilling your brains. Your wife should go out of town more often.
 
NVW said:
Any "vac. truck" operator should be able to help you out with that.:D Leo
Click to expand...

So I can get my white rat, I will get on that this week, already have the bat urine, ( wife thinks I am crazy) : but then, I have to wait until a full moon according to Radioman, Do I have to do a 6.5 ritual dance and swear, like a sailor, as I circle the vehicle ? But wait I used a seasoned high mileage 6.2 block so I might be alright. I have already done all the swearing I think I need.
 
Thanks for your information Bill.

You have always been a great help :thumbsup:

- Chris in Saskatchewan, Canada....:wink5:
 
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