47-55.1 Eliminate draft tube options

[leegreen]

Did you locate the leak that started the thread?

here maybe?

[TX3100Guy]

Originally Posted by leegreen

Did you locate the leak that started the thread?

here maybe?
Attachment 2330454

For sure, it was the cracked end cap leaking behind the timing plate. Not back pressure from a PVC in the draft tube as I had been wrongly advised by a friend.

The short version of this long thread is that I wanted to eliminate the draft tube. Then installed a PVC fitting in the draft tube block opening. Began running the engine, saw oil spilling out (not drips) and began tracing the leak. The end result, is pulled engine, removed valve train, push rods, lifters, cam shaft (with bolts holing the thrust plate), then removed timing plate to reveal the full damage to the end cap.

I will amend the title, but at this point it would be hard to find a title that addresses all of the issues covered so far. Thanks.

[dsraven]

ah, c'mon, how did you get those screws out? lol.
dont amwndthe title as you will lose those who have been following.
good to see it's apart

[dsraven]

sorry, I meant to say dont amend the title because you may lose some who have been following because they remember the title. if you do amend the title just put the name of the new title thread , and a link to it, at the last post in this thread so guys can find it easily

[1project2many]

It really hurts to see that cap. It's unfortunate but... buying a used engine is always a gamble. This teardown will give you a chance to confirm the rest of the engine is in great condition and you will have peace of mind that is reassembled to your standards.

Nice job cleaning the timing plate. I would probably think about replacing the well used countersunk screws in the timing plate with Allen head screws if they are available.

Following up on the comment about Roloc discs, it's probably a bad idea to clean any internal engine parts with abrasive discs. The abrasive material erodes and ends up all over inside the engine. Better to use a bristle disc.

[dsraven]

when I do an engine tear down I usually clean all the gasket surfaces on the block and head(s) and run a tap through all the threaded holes and then clean it all thoroughly. if it is getting dunked I still do all the mating surfaces first even though they may need or get a touch up after dunking. I try to use hot water when doing the final rinse, because it dries faster, and then I use a light oil like wd40 sprayed on the bare metal so it doesn't rust right away. when drying off after this I use compressed air and start with the blind holes to blow everything out, then oil galleries and cylinder bores and finally the large surfaces. then a wrap in plastic or a garbage bag to cover things up so they don't collect dust while waiting for assembly. this way all the grindings, rag lint, etc etc is washed away. dish soap works well on the cylinders to clean after a honing. oven cleaner works well on the cast parts as long as there is no aluminum or bearings in the area and then plan to wash it all well after.

[TX3100Guy]

Originally Posted by 1project2many

It really hurts to see that cap. It's unfortunate but... buying a used engine is always a gamble. This teardown will give you a chance to confirm the rest of the engine is in great condition and you will have peace of mind that is reassembled to your standards.

Nice job cleaning the timing plate. I would probably think about replacing the well used countersunk screws in the timing plate with Allen head screws if they are available.

Following up on the comment about Roloc discs, it's probably a bad idea to clean any internal engine parts with abrasive discs. The abrasive material erodes and ends up all over inside the engine. Better to use a bristle disc.

For sure the countersunk screws are getting replaced. Good idea on making Allen head, the flat bladed versions are a PITA.

The cleaning was done with a Vapor Hone that I have access to (120 psi air, water and zinc oxide) it does a nice job. The same facility also just added a powder coating oven, so some of the small part (no engine block ones) will get a nice coat of powder.

Thanks for the link on the disc, I'll order one tonight.

[TX3100Guy]

Originally Posted by dsraven

when I do an engine tear down I usually clean all the gasket surfaces on the block and head(s) and run a tap through all the threaded holes and then clean it all thoroughly. if it is getting dunked I still do all the mating surfaces first even though they may need or get a touch up after dunking. I try to use hot water when doing the final rinse, because it dries faster, and then I use a light oil like wd40 sprayed on the bare metal so it doesn't rust right away. when drying off after this I use compressed air and start with the blind holes to blow everything out, then oil galleries and cylinder bores and finally the large surfaces. then a wrap in plastic or a garbage bag to cover things up so they don't collect dust while waiting for assembly. this way all the grindings, rag lint, etc etc is washed away. dish soap works well on the cylinders to clean after a honing. oven cleaner works well on the cast parts as long as there is no aluminum or bearings in the area and then plan to wash it all well after.

Good info thanks for all the tips.

Spoke with my engine builder buddy this evening. He's recovering from Covid and is about to get back on things for me. We discussed several alternatives and I expect to get my engine to him in the next two weeks. In the meantime, I'm busy cleaning up my wiring, brake lines and generally cleaning the engine block.

[TX3100Guy]

I've noticed in working on this engine that many of the gasket surfaces (not the oil pan) that the previous owner used a blue silicon type gasket sealer. I've not seen anything like this before and wonder if that is something that I should look into. Right now, I use either the "Right Stuff" and/ore Permatex RTV type sealer. But the blue silicon material seems to seal better and frankly has been easier to remove.

[geezer#99]

While you have it apart you might as well check ring gaps too.
Boosted motors need a slightly tighter gap.

[dsraven]

rtv comes in several colours including blue. I have seen orange, red, blue, black, clear and copper. RTV stands for room temperature vulcanizing which basically means it cures at room temp. there are different uses for the different colours of the automotive brands of rtv. the right stuff is also rtv silicone but it has been formulated to cure fast, so it is thicker and a little harder to work with because you gotta be quick with assembly. there are also other handiman brands, or types, of rtv which come in all sorts of colours but a lot of those are not oil resistant. some of the automotive rtv is also not oil resistant. it is always good to know the rtv you have so you dont use it improperly.
here is a little write up on the permatex brand and their colours and uses
https://4lowmagazine.com/rtv-colors-...20applications.
and here is one from the jbweld site with their colours
https://knowhow.napaonline.com/jb-we...ilicone-guide/

[dsraven]

here is a permatex chart with the different uses and curing times etc
https://www.google.com/url?sa=t&sour...yBHLwYNgZRSBaI

[RustyPile]

I've been following this thread since the beginning.. I've been in this car repair business a mighty long time.. And during that time, I've seen some successful repairs made that many have said couldn't be repaired.. Freeze cracked heads and blocks, holes patched in the side of a block where a wayward rod went through.. I'd be willing to bet a highly skilled machinist (not an engine builder) could repair that flange area of the main cap.

[dsraven]

just as a side note, RTV is basically any silicone that is made to air cure but a lot of the stuff you find will not be oil resistant and is made for sealing or bonding. the automotive stuff is made to resist oils and heat etc but even some of those are not made for engine use but rather are for sealing glass or holding trunk rubber in place etc. it's always best to know your product. there are a couple of "the right stuff" RTV's too. one is a 1 minute cure and one is a 90 minute cure. grab the correct one if you wanna add oil or coolant right away in the affected area.

rusty, you're probably correct on the machinist thing and I think thats what is going to happen, a skilled machinist is going to make a new cap or fix the old one and either way the crank bores from front to rear will likely need to be checked for alignment and size. welding or brazing on the original cap may warp it so it will need to be checked at least. thats why the engine is taken apart and sitting on a table ready for the machinist to see what can be done. it's gonna be interesting for sure. prolly not cheap, but interesting.

[TX3100Guy]

Originally Posted by geezer#99

While you have it apart you might as well check ring gaps too.
Boosted motors need a slightly tighter gap.

At this point, I don't have the head removed from the block. Waiting on my new buddy to check out the motor as it currently is.

[TX3100Guy]

Thanks guys for all the RTV references, I have bookmarked them all and will use them for my selection, once I begin the reassembly process.

As a side note, my engine builder new buddy is also an accomplished machinist. He used to have a 12,000 sq ft shop where he could do anything and everything with an engine. In semi-retirement, his shop is only 3,000 sq ft now, but still has much of the equipment, just not as many cars/engines in the building. I'm confident that between him and his 94 year old machinist friend in California that they will come up with a solution for me......cost to be determined...LOL

[dsraven]

well, worst case scenario, they could find a used cap from a scrap engine and machine the flat surface down a little to ensure it is flush and allow a slight bit more metyal to machine in the bore, then line bore that hole round again to size, just so the cutting bit is set so it doesn't also cut the block side of the hole. pretty intricate work and work that a lot of machinists will say is not correct to do. or the bore could be made oversize on the front bore only. or all the bores could be line bored and get oversize bearings, if available. the final option is what most engine shops would want to do I suppose. maybe custom sized bearings are available somewhere. the engine fellas should probably know that since they have been around for a bit.

[TX3100Guy]

Originally Posted by dsraven

well, worst case scenario, they could find a used cap from a scrap engine and machine the flat surface down a little to ensure it is flush and allow a slight bit more metyal to machine in the bore, then line bore that hole round again to size, just so the cutting bit is set so it doesn't also cut the block side of the hole. pretty intricate work and work that a lot of machinists will say is not correct to do. or the bore could be made oversize on the front bore only. or all the bores could be line bored and get oversize bearings, if available. the final option is what most engine shops would want to do I suppose. maybe custom sized bearings are available somewhere. the engine fellas should probably know that since they have been around for a bit.

They have given me Plan A, B, and C options. I wish I understood them all. But these guys are pretty sharp and have thought through my situation. I do know that Plan A involves creating a new end cap from billet material. As for Plan B it sounds a lot like what you described, Plan C wasn't something that I understood.

They also plan on cutting another Woodruff key in the crank and the harmonic balancer due to the supercharger.

[dsraven]

the extra keyway is a great idea. sounds like they have you covered. you likely won't know what the plan is until they actually check the line bore so they know if the rest of the bores are where they should be first before they worry about the front one. no use spending time and effort to fix that and then find out the whole thing could use a line bore. knowing that first will likely change the plan A, B or C decision. kinda like knowing you have a bad spot in the road that needs to be fixed. no use spending a bunch of money on that bad spot and then checking the rest of the road to find it all needs paving anyway. might as well just pave the whole thing to begin with and not pave the same spot twice, if that makes sense?

[1project2many]

Boosted motors need a slightly tighter gap.

Maybe not too much? One of the big challenges faced by folks adding forced induction to late model engines is ring land breakage due to top ring expansion. Add boost, add heat, add ring gap.

Thanks guys for all the RTV references, I have bookmarked them all and will use them for my selection, once I begin the reassembly process.

Please also investigate anaerobic sealers. These sealers are opposite of RTV in that they only cure in the absence of oxygen. They are usually the best choice to use between two rigid surfaces, such as a rear main cap and the block. There are plenty of examples of situation in which RTV was not the correct choice and was not cured even years after it was applied. Classic examples include in manual transmissions and rear differentials.

Plan C wasn't something that I understood.

Did it involve a blueprint that looked anything like this?

[TX3100Guy]

Originally Posted by 1project2many

Maybe not too much? One of the big challenges faced by folks adding forced induction to late model engines is ring land breakage due to top ring expansion. Add boost, add heat, add ring gap.



Please also investigate anaerobic sealers. These sealers are opposite of RTV in that they only cure in the absence of oxygen. They are usually the best choice to use between two rigid surfaces, such as a rear main cap and the block. There are plenty of examples of situation in which RTV was not the correct choice and was not cured even years after it was applied. Classic examples include in manual transmissions and rear differentials.


Did it involve a blueprint that looked anything like this?

I believe Plan D is this:

[leegreen]

Hopefully it never comes to that!

But don't be bound by the historical significance of the engine if it starts to impact the way you want to enjoy the truck. Put it on a stand under a spotlight in the corner, stick something else in the truck and enjoy it.

[TX3100Guy]

Originally Posted by leegreen

Hopefully it never comes to that!

But don't be bound by the historical significance of the engine if it starts to impact the way you want to enjoy the truck. Put it on a stand under a spotlight in the corner, stick something else in the truck and enjoy it.

When my friend, who sold me the truck after he purchased as a retirement project but never touched it for six years, said when he heard about the cracked end cap "sounds like a small block to me".

I'm hoping that it doesn't come to that given the history of the engine, but you are correct, I want to drive this thing and take it to local car shows.

[1project2many]

I'm hoping that it doesn't come to that given the history of the engine, but you are correct, I want to drive this thing and take it to local car shows

This can be fixed. It's not impossible. It's made more challenging by not wanting to tear the engine down further, but it's definitely repairable.

But there is merit to building an engine that reinterprets the historical engine you have now. Modern electronics will do an amazingly better job of controlling fuel delivery and spark timing and will also be able to monitor for some failure conditions then try and take corrective action. And they will help the engine behave more consistently from idle all the way up to redline.

Maybe it's time to start planning your next truck?

[TX3100Guy]

Originally Posted by 1project2many

Maybe it's time to start planning your next truck?

To my wife's chagrin I've already begun talking about "what's next". I get as much enjoyment out of working (and learning) about the older cars/trucks as I do when I drive them.