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Hemi project, Junk Parts & Leftovers

Started by Flatdad, March 20, 2019, 07:51:39 AM

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Flatdad

I was wrong about the valvesprings, they're actually P3690933 only rated up to .500 lift or .510 depending on the source. I reckon I'd better just bite the bullet and buy the right valvesprings for the cam I have. My other Hemi is currently rocking a set of Comp beehives & I might just go with those again since they worked so well.

My replacement intake pushrod came in the mail & thankfully was the right length.

Flatdad

I was mocking up some parts & got a little carried away, lol! Seeing it looking like a complete engine keeps me motivated though...

JS29



Brads70


JS29


Flatdad

Take a look at the box juuuust above the offending filter in the first pitcher, and you'll find the replacement.  :vipermanhiding:

Seriously though, if they were truly prone to failing in a way that killed engines, they'd be out of business by now. I used to use them exclusively & never had problem. I've never met someone who actually killed an engine from using one either. Cheap junk inside, yet functionally adequate.

Scooter

Drop it in just as it looks now... no fresh paint with more colors than the Mexican flag!  :))


JS29

If the drops it in as it looks now, He can't install the fan belt!  :no:

Flatdad

Quote from: Scooter on April 24, 2020, 12:56:59 PM
Drop it in just as it looks now... no fresh paint with more colors than the Mexican flag!  :))

You should see the green $100 valve covers that are going on it too!

Seriously though, the repop covers in the picture are actually gonna get cannibalized to fix up a set of thick, factory '70-71 covers that someone ground off the tabs & fogged green.  :barf:

Flatdad

I've had this project on the back-burner, because the Challenger needs to be 'done' first.

One thing has nagged at me though, I didn't know the cc's of the dome on my mystery pistons.

Yesterday I sat down with a few measuring instruments, a piston, and a CAD program. Painstakingly, I modeled the dome & valve reliefs as accurately as possible & then used the software to calculate the volume.

Mission accomplished, here's what I came up with:

Compression Height = 1.765"
Dome Height = .515"
Dome Volume = 85.4cc +/- .9cc
Pin Bore = 1.094"
Rings = 1/16", 1/16", 3/16"

I had guessed it would be about 80... we're gonna need a bigger head gasket...


Flatdad

Measured a rod yesterday at 6.8605". So far, as long as the crank is accurate, the specs are currently:

4.15" stroke, but not checked yet
4.31" bore
6.8605" rod
1.765" compression height
85.4 cc dome
169 cc combustion chambers, but I haven't cc'd the milled heads yet.
10.6395" deck height, it needs cleaned up .010" or .020" though.

I can make .122" worth of gasket thickness with my spacer (.059") & 3 steel shims (.021) stacked 2 on one side and one on the other. Or.... blow the budget on some .140" Cometics...

10.63" deck with .122" gasket = 11.2:1
10.62" deck with .122" gasket = 11.5:1

10.63" with .140" cometic = 10.8:1
10.62" with .140" cometic = 11:1

...Or have the local laser jet place make some thick deck spacers.


Flatdad

Last night I carefully mocked up the crank in the block with one rod & piston to see how accurate my measurements have been + check the crank throw.

I must have done something right, because I should have seen seen a theoretical .576" of piston out the hole & the actual measurement was .574"!

It appears the the 4.15" crank & stock Hemi rods are going to clear everything in the crank case as well.  :banana:

Chryco Psycho

Good news . it pays to check everything carefully !

Flatdad

Short Version: Stripped the block bare, sent it to be machined, messed with a cylinder head.

Long version:

Over vacation...

I stripped down the block including oil galley plugs & core plugs. The core plugs were a royal PITA to get out! Even though they were fairly new steel plugs, I wanted brass.

I also took a wire wheel to the sides of the block to investigate the blown up skirts. As suspected, I was greeted by two huge lumps of Bondo where the motor mount pad should have been. On a positive note, the damaged skirt areas had been fully welded. It appears all the Bondo was used to seal up pin holes, thinking I can do a better job. Last, I installed my first Helicoil, renewing a damaged head bolt hole.

Last week 'til now...

I hauled the block to the local machine shop with a list of items to take care of:

Clean the paint off, mostly the flaky red glycol in the interior. I wish people wouldn't paint that stuff in their blocks.
Parallel deck & finish for MLS head gaskets.
Bore & Hone with a torque plate 4.315", finish for plasma moly faced rings.
Line hone, because #1 main cap was replaced.

Last night, I worked on the ebay cylinder head a bit. All the valves are tight in the guides, but some are too tight & will need some adjustment. Turns out, my mismatched intake valves have different stem diameters. 6 measure .310" & 2 measure .309" Not a big deal, but you can feel it.

One intake bolt hole will need drilled out & Helicoiled, some gorilla twisted a bolt off in the hole. All but two rocker stand dowels are missing & they need replaced anyway. Other than that, I used a tap set to lightly clean up all the threaded holes.