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Sudden Increase in Blow-by

Yes. It was part of the blower kit I bought from BDS.

I mentioned this in passing earlier but now I'm thinking this was a significant contributing factor. The intake-to-head bolts were not properly torqued and several of the inside bolts were almost finger loose. The bolts that came with the BDS kit were socket head using a hex drive. I couldn't get to the bolts down in the pockets with the torque wrench with a normal hex drive and had to use a extended ball-head hex drive...

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As you can see the drive is at an angle to axis of the bolt. I don't know exactly how this affects the torque reading, but I assume the actual torque at the bolt head would be a little less than what is indicated on the wrench. I torqued an extra 5 lbs. to compensate. :rolleyes: Still, none of these bolts stayed torqued. Again, no thread sealer or Loctite was used on these bolts.

I 've jacked around w/those funky allen head bolts on my TR , I think I'm gonna replace them the next time w/12 point small head boltsv , I have a 12 point universal socket & 12 point box end wrenches that would be a heck of a lot easier to use in tight areas...
dave
 
Yeah, I'm going to go with something different, too. Since all but the four corner bolts are under the blower and can't be checked/re-torqued without pulling the blower off, I want to make sure they stay put!!
 
All part of owning an "exotic" power adder. Run it thru a few heat cycles, remove the blower, re-torque the manifold bolts, rinse and repeat. Do it after a thousand miles or until the gaskets are seated and the bolts are done stretching.

John

These things are not "set and forget". Stay on top of the situation or see the results like the first engine.

P.S. Don't forget the steel washers under the manifold bolts.
 
I 've jacked around w/those funky allen head bolts on my TR , I think I'm gonna replace them the next time w/12 point small head boltsv , I have a 12 point universal socket & 12 point box end wrenches that would be a heck of a lot easier to use in tight areas...
dave

Lee, I use crows feet wrenches and torque wrench. They come in 6 point. 12 point, and flare nut wrench styles. Can use either a 3/8 or 1/2 inch torque wrench to tighten. Some I have even used an offset distributor wrench with a homemade adapter to torque the bolts down. Have always used washers and Loctite with any bolts used with aluminum intakes and never had any leaks. Good luck and good thoughts, Bruce
 
I can't get the copy and paste working, but go to AC 43.13. Then open up Chapter 7 and look at page 7-8, paragraph 7-43. AC 43.13 has a lot of good info you can apply to automobiles.
 
Here's an update for anyone who is still following my saga. Got the motor torn down to bare block. Took the block, rotating assembly and heads to a well-respected auto machine shop near me. Block is definitely cracked. The tech said he has seen that type of crack before... typically due to water freezing in the block. This could have happened while I had the motor stored in my hangar while I was getting the frame and body painted. I did not completely drain the block, but it had 50/50 coolant in it. Who knows...:rolleyes:

Tech says the rings definitely never seated properly and the cylinders are "polished." Rings look to be chrome moly. Tech recommends cast iron.

Crank is GMPP cast steel. Tech says it is probably OK to reuse considering the relatively mild use the motor is seeing. Rods appear to be stock GM. Tech says I should upgrade. Pistons are cast F-M Speed Pros as was previously determined. Tech says I should definitely go to forged.

Current plan is for this shop to order a Dart SHP block and build a new short block with the current crank and new forged rods and pistons. They are working up a list of specific parts and a quote.

An interesting note about my cam. I did not get a cam card from the original builder of my short block. He said he lost it. He said it was a Comp Cams "blower" cam and that I would really like it. Well when I pulled the cam I checked for any ID info. On the back of the cam the number CC 12-414-8 was etched. I ran it on Comp Cams web site and here is what I have...

12-414-8 - Xtreme 4 x 4™ -Due to the allowances of lower engine speed, these designs are slightly more aggressive than the original Xtreme Energy™ Hydraulic Rollers. Great low & mid-range torque. They are one of our most aggressive hydraulic roller lobes and run well in street, off-road & four-wheeling.

LOL, an "Xtreme 4x4 cam!" Actually the specs are pretty impressive and I have always liked the cam. Rumpity idle (blowers tend to smooth out lumpy cams), lots of low-end grunt and the motor has always breathed well.

Well, we'll see what the shop comes up with. :cool:
 
It's a pretty tiny crack. I'm guessing the coolant was boiling off before it could mix with the oil... thus the steam coming out the breather. Heck, I don't know. Alls I know is I'm getting a new block!!:thumbsup:
 
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I am no engine building guru, but I would question the ring choice. Maybe Screaming Metal will chime in. My thoughts are cast iron, the cheapest made, seating time a little longer than moly, but quicker than chrome. Moly, a good all around ring, seats relatively fast and has a medium durability surface. Chrome, the toughest surface, needs a coarser finish to seat, takes a little more time to seat, very durable. Good luck with all, still watching and reading.
If new pistons and rods are on the menu, I would go for the stroker, 383 crank. Cast steel chebby cranks have to be cheaper than Ford stuff. The Ford 393's run about $200.
 
I'd go with a forged steel crank with dual keyways since you are running a blower and a matching balancer that has the 6 blower pulley bolt holes in it. You'd be surprised how much stress you're putting on that crank snout with that blower pulley and belt.
 
Thanks Grant. I already have the dual keyway hub from the first motor. Came with my blower kit. I didn't know about dual keyways back then and didn't have the second keyway in the old crank. I have spec'ed it for the new build.
 
Yea, Lee, There was a tell-tell slickness look to the bores....rings look like they didn't seat.
If it were me, get a seat of Sealed Power Crome-Moly top ring with Cast 2nd w/ expander oil ring.
They do make a Hard Cast top ring, with a stock cast 2nd....either will work good in your case.
The chrome-moly top ring setup is a good ole not fancy dependable hotrod ring setup most folks used thru the 70's on thru to the 90's....
You can go as fancy or as simple as you want. Simple has always won the races, kept the motors running on the streets.
I'd go with the stock steel truck crank, with chamfered oil holes/ magnafluxed/ shotpeened/ stress releived. But the stock cast one will work it your not romping on it frequently. I would send it of to be deburred, oil holes chamfered, nitrided, and micropolished, at the least. Have them check the indexing and the balancing also. That, even though is a stock cast crank, will live a long life behind that blown motor IF you keep your foot out of it.
Pistons need to be forged, and the rods steel with good bolts.
The Forged Pistons have come down in price so much, theres little diff. in the money, while a Big gain in strength is had.
Steel rods aren't as prohibitively expensive as they used to be, but, you can get some good street rods thru RHS or Scat.
SINCE, your gonna be getting the rods and the pistons, send the whole thing off, crank with the flexplate, drive hub and all have have it balanced. A few more dollars but well worth it. Send the bolts for the flexplate and the drive hub and tell them to label them.
Not all bolts are the same length, etc, and that effects balance. I normally etch the #'s on....keeps stress risers down on the bolts.

Since you can't get a direct pull on some of those intake bolts,(allen wrenches flex when using long ones, only the short ones won't flex), go with the ARP 12 Point bolts. And use washers on the blower intake.
When you torque down, do 3 stages, once @ 10 or 15 lbs., once @ 25 to 28 lbs, then at your final pull.
Use a thin coat of silicone on the threads on install, it will seal the threads, it will also act as a thread lube to give you a truer torque reading...
Remember, let it sit a while, then retorque, that gives the bolts a chance to stretch slightly, if they are, and then doublecheck the torque....

as far as a cam, a stock cam or something close to stock is fine. At the low rpm your motors turning at low boost....your not gonna see any horses anyway (not from the cam, anyway).
(Your suppossed to use a 'Blower' cam, which does help, but only on higher rpm motors)....
That blower pressurizing your intake is all you need....don't try to reinvent the wheel here, its a nice blown TBucket not the Space Shuttle....
 
Also, there have been alot of casting flaws in that area of certain blocks....no suprise....
It was a casting flaw in the mold, that gets transfered to the blocks, the reason why it was small.
 
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Do me a favor, look at your roller lifters, and on the roller, does one side of the roller look brighter or smoother? Take a pic of the cam and let us see it.
Reason being, a cam of that grind is usually a reg. cam (cast), which has a taper on the lobes to spin the lifters.
If the guy put regular cam in, running roller lifters, the rollers will need to be touched up. If its the correct steel roller cam with the lifters, your ok....
 

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