XXO/BVGC '38 Chevy Coupe Build

[Glen]

I removed it as we have a how to section that should be used but broken down to the subject shuch as the bolts and studs etc.

[jimmy six]

May sound goofy but try to "glue" a piece of thread around the holes that leak...Always worked for me and my leaking GMC's when I used copper gaskets. Now I use Best and they have been woking fine. The 2 dowels are very important also...Good Luck

[Buickguy3]

  We had similar issues with the engine in the Cat, and we did as Jack says, converted to dry head and deck surfaces. Cured the problem of blowing all the water out of the cooling system. No more water issues. Made about 20 pass' this year and never  had to pull the top off of the engine.
   Doug 

[Rex Schimmer]

Buddy,
If you are going to be in Santa Rosa to see Dema this week let me know and I will buy lunch or at least a beer!

I  have to agree with Woodie regarding the torque of the studs, they are just very stiff springs and setting them with a torque wrench is really a "second hand" method of seeing how much stretch (preload) that you have put into them therefore it is very important to properly lubricate the threads and the nuts to insure that the torque is an accurate measurement of the stretch. You might think of using a dial indicator to establish the amount of stretch in each stud and then check them against what the torque wrench reading is. First you have to establish what the proper amount of stretch is to get the stud preloaded in the 80-90% of yield range. If you are having a situation of having the studs loosen during runs you could have a situation of thread yielding in the block which is probably only "fixable" by doing to larger threads on the stud end that screws into the block. As Woodie  was saying thermal expansion when torqued to tight can actually start to stretch the studs. I would suggest that you accurately measure the length of each stud and then assign a position in the engine for each stud and then re-check the stud length at each engine tear down. If they are stretching then they are to tight or not large enough for the load.

Rex

[maguromic]

Rex, I thought you were hunting all week.  If you are buying lunch I will show up too  , I have some cams to pick up from Dema. Tony

[RichFox]

Buddy; If you are going to drive up 101 through San Mateo and across the Golden Gate. I am about 15 seconds off 101 and the transmission is pretty close to the door.

[Jack Gifford]

Doug- lots of off-the-shelf parts kicking around to dry-deck a Buick straight-eight?

Someday- I'd like to see what the new circulation path is. Still use coolant in both block and head?

[RichFox]

My Plymouth with the Ford head as well as the Pontiac I ran in the Vega were both dry decked. The Plymouth has a large odd shaped at the front of the deck. It was very close to or in the combustion chamber of the Ford head. So I cut a piece of iron to fit and ground a good kerf on it and had it welded. All the other holes were tapped for taper thread plugs and everything was surfaced. All the Pontiac holes got pipe plugs. Water went into the back of the heads (or head) and out the front. into the front of the block and out the back. On both engines I made my own solid copper gaskets without water holes in them. Seemed to work fine and cured the Pontiac of it's blown head gasket habit.

[Rex Schimmer]

Pretty hard to beat the advice from guys that have "been there, done that" like Rich and Doug. Dry head and deck surfaces make a lot of sense. Sure would make the head gasket simpler and more reliable.

Rex

[38flattie]

Wow! Lot's of good advice while I was away!

Rich, see you Tuesday

Tony and Rex. does Tuesday morning, or lunch time on Tuesday work for you?

I appreciate all the replies! Thread, silicone, Hylomar (which we use) are all good ideas. Dry decking it would be nice, but it looks to be an extreme amount of work for the odd shaped water passages, Look at the first pic- How would you guys go about plugging these passages?

I'll discuss dry decking the block with Don- it does seem to be the absolute to the issue.


We tore the engine down Wednesday night, and I was surprised! The bearing looked great- no signs of flex or movement! The front bearing showed just a touch of possible flex, I believe due to the blower drive.

We couldn't be totally drama free, however- on 5 cylinders, the lifters had backed themselves off, and we had valve lash in the ,250-.300 range! luckily, only  two lobes on the cam showed any damage as a result. Even those lobes will clean up with a quick polish.

We didn't finish until 4:30 a.m., so we're a little shy on pics- good thing there wasn't any carnage!

So, next week I'm off to deliver the block to Don, cam to Dema, and see if we can make some gains with flow. My goal is to try and pick up 30-50HP through additional porting, tweaking the head chamber design, and a new cam.

[RichFox]

The deck does look labor intensive to seal. I would guess you could do it with cut to fit plugs and stitch threading and JB Weld around the edges. The lifters look like they have room for pal nuts.

[Jack Gifford]

... How would you guys go about plugging these passages?...

You'll probably get lots of suggestions. Personally, I'd use a manual mill to "trim" each opening (heads and block decks) to geometric shapes (circles, etc.), for which individual aluminum plugs could be machined (CNC would be nice here, for polygons with radiused corners, etc.). Interference fit could be calculated to not worry about different thermal expansion rates of iron/aluminum. Somewhat tedious, but not as bad as some similar efforts that I've succeeded at.

What am I missing in the picture? It gives the impression that the two threaded lifter parts are only accessible for wrenching when the lifter is not on the base circle?

[Rex Schimmer]

Buddy,
I am retired so of course Tuesday works for me!! Give me a call at 707-484-5721 and we can arrange something. Probably meet at Dema's shop? To bad it looks like rain as we could go to the "Hot Rod Lunch" at Fred Stoke's place but it is out side and rain makes it a no go.

Call me if you have time to get together.

Rex

[Freud]

. Probably meet at Dema's shop? To bad it looks like rain as we could go to the "Hot Rod Lunch" at Fred Stoke's place but it is out side and rain makes it a no go.

Rex
[/quote]

Hey Rex, detour to Jack's Garage for breakfast. It never rains at Jack's. Even if it did JD Tone would supply umbrella girls.

FREUD

[Rex Schimmer]

Freud,
When I am in So Cal I never miss a morning at Jack's Garage!!! Great place and great people. Have you ever seen the quilts that Jack's wife makes from old Bonneville Tee Shirts? I plan to take a bunch on the next trip south to have her make me one. They are neat!!!

Back to blown Cad flatheads!

Rex