Missy and DaHoooley, the SAGA continues

[Missy Good Wench]

Here are some piccy's for Y'all to drool over, taken this afternoon.

Missy

 

[Crankme69]

Oh man that looks nice! Thanks for sharing them pics with us

 

[deejaaa]

oh yeah!

 

[Missy Good Wench]

Well lets just hope that it runs as good as it looks and lasts a long time.

Missy here has gotten goosie after the last debacle.

Missy

 

[deejaaa]

Well lets just hope that it runs as good as it looks and lasts a long time....................

X2

 

[Missy Good Wench]

OK More piccy's and a lesson to be learned.

I installed the cam, sprockets and chain, buttoned the retainer plate up using BLUE loctite on the little bolts.

Had to rob the crank keys from the old GM crank.

Got the pump drive gear on and buttoned up the cam gear blot with Blue loctite as well.

Try as I might I could not feel any real end play in the cam ?????????

I sat and thought about it some, then I remeber that I had switched cams on this build. The cam that ws in the "YELLOW" engine had some circumferential marks on several of the lobes and the lifter rollers.

Sooooo Missy here dug through the goodies and found a very nice cam from a 6.2/6.5 ????? same came anyway.

The little round ring spacer that goes behind the key and nest to the front of the cam is what controls end play.
The retainer plate thatn bolts to the block in conjunction with the ring is what regualates the end play.

The Book says .002" to .011" of end play and I had barely .001"

Sooooo, I yanks the key from the old cam, then removed the spacer.
I removed the gears from the engine then the cam key, spacer and such and measured them.

The one I had that came with the cam I am using was a tad thin, resulting in things being too tight.

I swapped the original ring in and all is well.

The piccy's show everything along with timing marks in their proper location.

DONT FORGET TO CHECK THE END PLAY especially if your mixing and matching parts.

If the parts are all the same and kept from the same running engine, you will be OK, STILL Check it to be sure.

Another thing is to be sure that with the cam gears off and using the cam bolt to pull the cam in and out that you have at least 1/32 to 1/16 of clearance BACK from having the cam touching the retainer plate,

If you drive the cam rear bore plug in too far, the cam will rub on it and can make metal shavings that can cause damage

Once all is well, use some JB weld around the bore plug/block to be sure of the seal. No need to pile it on, just a ring where the plug and its bore meet.

This will make sure there are no oil leaks.

If you buy and aftermarket cam, be damned sure that the rear cam journal has a HOLE to allow oil that passes the bearing to escape into the engine and not push the plug out. I have seen this once many years ago on a 6.2

The cams rear journaL did not have a drain back hole. Its usually fairly good sized maybe 3/8".

Hope this stuff helps

Missy

 

[deejaaa]

where would the wear have been if you had left end play at .001? when i saw your pants in the 1st pic, i was sure this was just a show and tell but then i saw some grime in one of the others. you must be right handed.

 

[Missy Good Wench]

Had I not swapped the spacer with the thicker one, the back of the cam sprocket and the retainer plate would have likely galled up and cause significant problems.

I dont know if it would have seized up but less that very limited clearance would have caused issues.

I am right handed though. I had the camera in my right hand.

This is just another area, that unlike the small block and big block chevy, must be tended to carefully.

Having too much end play would seriously effect the injector timing as the cam could walk in and out.

The pump gear would then work in the teeth which are a helical cut and the timing would advance and retard.

Without a injector pump such as a gasser chevy or ??? the chain will keep the cam pretty well in place.

The retainer is basically a thrust plate.

Missy

 

[Missy Good Wench]

OOOOOOK

WELL now, the day was a good one and I accomplished some things today.

Finished cleaning pistons and got them all washed up and started installing them on the rods.

The Kids came over with some friends to do some dirt bike ridding so I got side tracked a bit.

Had Pizza for dinner and Im gonna call it a day now.

Next session will hopefully see the rest of the pistons on the rods and then get the assemblies installed in the block.

Missy

 

[JiFaire]

Good work, Robyn! Glad to see you back at it!

Jim

 

[Missy Good Wench]

In there swinging at it anyway

Missy

 

[Missy Good Wench]

MID COURSE CORRECTION​

Over he weekend I got some good work done and all the pistons ready to go in.​

The pistons were a low mile set from a warranty engine from a GM shop.​

Very low miles.​

Well one piston had some scuffing on it at the area just under the crown.​

Looks like maybe the engine may have ingested something ??​

Not enough to really hurt anything buuuuuuuuuuuuut, enough to make me look at the part with a close eye.​

Considering the long and convoluted mess that this thing has been, I dont want any issues.​

Soooo I set about scrounging up another piston.​

Some digging revealed that these pistons were early 6.5 stuff (92-93) and had the thinner crowns.​

Hmmmm went back through my parts and discovered that the pistons that came from the original engine that was in DaHoooley (97 crate engine) were in great shape and the later, thicker head type.​

Sooooooooooo, I set about measuring all of them to verify sizes. I needed two pistons for cyls 7-8 that measured 4.0495 and the remainder needed to be 4.049​

Since the block was honed to allow the use of the first set I did not wish to refit different sizes.​

OOOOOK​

I have two pistons that match up for cyls 7-8 and 5 that match up for 1-6​

BUUUUUUUT there is one odd duck that is 4.055" diameter.​

As these engines are all select fit its the luck of the draw when it comes to parts.​

The pistons on these engines are all marked under the pin boss area with painted lettering.​

JT is a production standard, KT is also a production standard but slightly larger followed by GT which is even larger.​

The JT pistons can vary about​

The one I have is an ST and its larger yet at about .005" over the standard.​

JT Pistons measure at 4.049" to 4.050" This size is normally found.
KT Pistons measure at 4.050" to 4.051" This size will be seen.
GT Pistons measure at 4.0514" to 4.052"​

I dont have a late enough GM manual to show the ST size but its definately a production size used in the select fit process.​

My book is a 94 book and the ST piston came from an early 97 (first design squirt block)​

The difference in the late and early pistons is very subtle.​

Looking into the piston from the bottom the early ones have sort of a stair step look to them and the later ones are a curved underside without any steps in the area under the crown.​

What this equates to is that the crown (Head) of the piston on the later engines is thicker to help stop cracking.​

Early pistons were known to crack if the engine was run real hard with high EGT's​

Soooooooo, no biggy here as this does not slow things down much, just have to clean these pistons up and then get them onto the rods.​

The engine that was in DaHoooley when I bought it ran good and had low less than 100K miles and was nice, except for the cracked cyl walls.​

These pistons should be fine.​

Better to fix this stuff now rather than later.​

I will try and snap a Piccy of the two different types of pistons and post it.​

Also, keep in mind, if you are mixing and matching pistons to put an engine together.​

Be sure all the pistons have the same Compression distance which is the distance from the top of the piston to the wrist pin C/L​

GM did some fooling around with the compression ration in later years and dropped the comp ratio a tad.​

SOOOOOOOOO, its easy to compare pistons.​

Just pick one of your set and use a psiton pin to insert between two pistons and compare the tops to be sure they are equal.​

If you find one or ??? that are higher or lower then you need to pay attention.​

GM raied the pin height on some later pistons to drop the ratio a bit.​

KEEP ALL PISTONS THE SAME.. have a set thats not all the same ratio would be a really bad idea as this would cause harmonics to develop that could over time casue sever damage.​

The other issue would be an engine that was ROUGH running.​

Having either ratio is fine, just dont mix and match.​

All production pistons weigh the same, even oversized ones. This keeps things all in ballance using a stock crank.​

Now if your doing a ballance job you can check this out and make any slight adjustments needed.​

When assembling the engine the pistons should be flush with the deck to no more then .005" above the deck.​

Anyway, so much for piston tech.​

Missy​

 

[deejaaa]

i had no idea!

 

[3500GMC]

Good eye Missy.

A little further on piston tech.

Some findings on my last 6.2 build, some aftermarket (sealed power for one) lack the steel top ring land. Bad bad. Even if you HAD to use these, (why would you) the pistons are 450-500 grams LIGHTER and will stress an already stressed crank to failure if one doesn't balance the assembly accordingly so forget about using just 'one' as a replacement.

 

[Missy Good Wench]

Yesssssssssss indeed, the Ni resist top ring land insert is an absolute must have.

I have heard of these pistons (without insert) but never seen any.

Got together with my buddy this morning and scrounged through a box of pistons and found a lovely one that's the right size.

Now I will get at cleaning the set up really good and inspect them for any issues.

They look great and the engine was performing fine. The only issue on that one was the coolant leak inside.

Missy

 

[3500GMC]

I have heard of these pistons (without insert) but never seen any.

Missy

They're made in INDIA. Surprise surprise huh?

I sent 'em back.

Good to have good slugs.

 

[Missy Good Wench]

Oh yeah buddy

A gasser could work fine with those slugs, not the 6.5

Bought a ring groove cleaner tool last night and went after the pistons this morning.

JOOOOOOOY at last. Took about an hour to do all 8 pistons without killing my hands scrapping the ring grooves with a broken ring.

Got to sort though a box of late model pistons and scrounged up 8 pistons that meet the size needs of my engine.

Took sorting through 3 sets of pistons to get 6 that were 4.049" and 2 that were 4.0495"

Just wanted to get a set of late GM pistons.

The pistons in these has not been much of an issue. Just the real early ones had thinner crowns and under hard use could crack in the recardo bowl area.

High EGT's can cause cracks in the piston crowns.

The pistons I got were fairly low milers by the amount of crud on them.

I used a set of 200K +++ miler pistons in the 94 Burb I rebuilt, and its still running great. The last I knew of it, it had 50K miles on the rebuild.

 

[Missy Good Wench]

GOOD NEWS​

Got to work on the little monster this morning before it got hot out in the shop.

Got all 8 pistons assembled to the rods, the rod bearing clearance all checked and the entire rotating assembly all together.

JOY at last, all the pistons come flush with the deck when they pass through TDC.

All torqued up and ready to install the oil pump, the timing cover and the pan.

I need to get a set of head gaskets and a few others items but its starting to gain some serious ground.

Damn, this thing might just run before rain flies again.

Keep ya posted as it comes together. More piccy's soon.

OH and for all ya Purists out there, Yesss Imma gonna paint it CAT YELLOW AGAIN.

Later troops.

Missy
​

 

[DieselCash]

OH and for all ya Purists out there, Yesss Imma gonna paint it CAT YELLOW

That color looks real good on a 6.5TD! :thumbsup:

I can't wait to see the pictures. :hihi:

 

[deejaaa]

That color looks real good on a 6.5TD! :thumbsup:

I can't wait to see the pictures. :hihi:

X2!