'68 El Camino, lumpy high comp. 350 engine, TH400 trans, need TC advice.

[RichardSIA]

Bought a '68 El Camino with a 400/400 drive-train.

The engine ran out of oil pressure and I bought a used "1970 Nova 300 HP" from a guy doing an LS conversion.

About the time I got the new engine cleaned up and ready to install I found out it no longer has flat top pistons and 10.25-1 compression.

Not sure what the compression actually is, I never had the heads off.
I figure it has to be at least 11-1, cam pulls to the moon, but wants to let the engine die at 900-1000 rpm idle with the TH400's stock 1500 flash converter.
I never had the cam out to look for numbers either, it likes the top end, 6500 RPM and it will go higher if I let it.
Wish I could talk to the engine builder.

This TH400 trans and TC worked fine with the 400" engine.

With this 350 it's pretty bad.
Tries to stall at idle so I'm having to manual shift it, not good with the stock column shift.
Bangs into gear, have to apply gas to stay running, not good when trying to remain low profile to John Law.
Shifts way too early now with mild throttle, not a lot better with the pedal held down, and it's pretty dead until around 2500 RPM or more.
10" of vacuum at 1000 rpm, using a reservoir and still need to add a vacuum pump for brakes at lights.
The kick down does not seem to function anymore, I know the switch is good, I can hear it when I work it manually with the engine off and it worked on the old engine.
Stock 3.55 rear gears, 245/60-14 25.6" BFG rear tires.
Double pumper 650-700 CFM carb on a Performer manifold (Will switch to a Performer RPM ASAP, was a Torker II when I bought the engine).

Everything feels so tall I cannot really get a feel for the cam or when the manual secondaries kick in unless I force it down into a lower gear.

Not into drag race AT ALL, cruising rpm is around 3000 - 3500, also has to live in some city traffic.

What I really want is to have this a bit more street-able around town without breaking more engine mounts but still take full advantage of this engine on the open Nevada roads.

If cost and time were no object I would throw a manual trans in and grin from ear to ear.
For now I need to keep it on the road as my daily driver.

Hoping a 2400 stall is enough, also hoping to be able to limit trans slip at highway speeds.
As usual some of my desires may be contradictory.

Suggestions without breaking the bank, changing the cam (It's a lot of fun when I get to let the RPM work for me) changing out the pistons etc.?
I have a 327 I am gathering parts for that will make this 350 look stock, hopefully next year, with real gears too.

[pitts64]

delete

[RichardSIA]

I tried a Q-jet, a rebuilt one that was fine on the 400.
It was miserable on this engine, would not restart when warm, no power.
Got some books and advice to tune it, gave up on it when nearly everyone began with "Get a large pile of used Q-Jets for parts, many are no longer available new"!

So I put the Double-Pumper back on that the prior owner had used.
I figured it had to be at least reasonably well matched to this engine.
Once I adjusted the float level and idle it runs pretty well, VERY well if I manually shift to second from third and stand on it.
Goes to "Arrest me now!" speeds about as fast as any car I have ever driven.
I'm actually going to need a speedo with more dial space and bigger numbers.

Once I have the trans sorted I will go to a chassis dyno for final tuning.

[67rstbkt]

Small world, Richard :) That's my brother you got the set-up from, I guess the original owner of the engine never called you? I really wish I knew more about the setup before we pulled it, sounds like it's more race than street.

[Steve Chryssos]

Sure sounds like the trans has a bad (or disconnected) vacuum modulator.

[RichardSIA]

No, he never called.
Curious what gears the Nova had in it, did you find any timing slips in the car from bracket racing?

I'm still playing with the timing.
Should have pulled the timing gears and gotten the cam number before I put the engine in.
Just got the manifold changed to a Performer RPM.
Now trying to fix fuel line fitting leaks on the double pumper.
I had it rebuilt locally, the rebuilder dropped ten jet sizes and replaced the defective secondary metering block that was preventing the secondary squirters from working.
Think I need to add a governor calibration kit to get the TH400 to shift a bit later.
Disappointed I have not been able to drive it much, the low brake vacuum at idle is still a bit of an issue along with getting the engine dialed in.

[RichardSIA]

Looks like I finally have it tuned just about right.
Despite a little too tall converter/gears it will burn a tire pretty well a few feet after I start as the cam comes on, chirps very hard into second.
If I had my M21 in this puppy I would be in jail by now, and still smiling.

Thinking a governor mod kid will just about take care of it now until the new frame, 327 engine, and M21 are ready next year.

[67rstbkt]

Looks like I finally have it tuned just about right.
Despite a little too tall converter/gears it will burn a tire pretty well a few feet after I start as the cam comes on, chirps very hard into second.
If I had my M21 in this puppy I would be in jail by now, and still smiling.

Thinking a governor mod kid will just about take care of it now until the new frame, 327 engine, and M21 are ready next year.

Sounds like it's coming along - haven't been on this site in some time, sorry for the long delay in response. The Nova is further apart, no timing slips unfortunately. It should hopefully be ready for soda blasting in the next month or so. The rear end will probably come out sometime in the near future. When it gets to that point, I'll see what it has in there for a gear ratio and let you know.

[RichardSIA]

I should update this thread more often
Been VERY busy of late and the winter weather is not helping.

Found out why the engine was so hard to tune and had such lousy idle with no vacuum.
Turns out the cam is an aftermarket Duntov 30-30 clone.
Nothing there below about 3K RPM and would run to around 8K if the engine could breath and held together.
Great for a 283 or even 327 in a light manual trans car, terrible in a heavy El Camino with a TH400 and tall gears!
I may just use this cam again, with my Muncie and 3.54 Jag IRS rear.
With this intake and stock heads the engine fell flat on it's face by about 5500.

Had an issue that when I took a cloverleaf turn fast the engine smoked like a steam train and spit oil out the exhaust!
So I pulled the heads, pan, and cam.
I think the engine may have sat for a while and the rings lost their tension?
Cylinders still show cross-hatch from the last rebuild and have no ridge.

Now working on building a hot 327 to put in front of the Muncie and gear vendor overdrive.
Also hoping to get a fiberglass nose for the car to shed more weight.

Rear quarter repairs are fairly well along but need to be finished.

[RichardSIA]

Ugh, I cannot complain about other folks slow builds since this one is going on TEN years now. :pat:
Recent life events have put me into "Git er done" mode with the El Camino and Lotus Europa as priorities.
Cut down the fleet significantly and will probably let a couple more go too.
Putting all I can into the priority builds.
El Camino Scorpion rockers are finally ordered, billet cam for the Lotus is ordered too.
I know I should just do one or the other but both are "Bucket list" items for me.

[RichardSIA]

I have the 4x44 IDF Weber intake nearly port matched to the Brownfield heads. :)
Near enough to bolt the individual manifolds back on and blend them to the intake.
I will do the final matching after the heads are fully installed.

[RichardSIA]

I guess I never posted the updated build plan.
Here it is, would probably be done by now if I had not gone crazy for real performance part$.
This EC is standing in for the car I will never be able to replace at current prices, my old Jaguar XKE Roadster.

1968 El Camino fast road car build specs.

Target weight - 3,200 pounds or less.
7K RPM 333" SBC with 4X44IDF Weber intake, M20 with GV overdrive, 3.92 rear gears, all wheel disc brakes.
Exterior to retain an early seventies mild hot-rod look, drivetrain also mostly mid-80's parts, right down to the finned Larsen valve covers.

Engine:
Bore 4.040
Stroke 3.25"
Cylinder head volume 64cc
Effective dome volume -5cc
Deck clearance 0.010"
Compressed gasket thickness .028"
8 cylinders.
Compression 10.75-1
Displacement 333.29" - 5463.77cc
Pistons, Custom JE forged pistons
Heads, Brownfield Aluminum (Same as early AFR) refurbished at "Heads By Rick" in LV.
Crankshaft, Eagle 327 3.25" throw.
Eagle 5.7" rods.
Cam, Crower #CRO-00323
Cam Style:Mechanical flat tappet
Basic Operating RPM Range:3,000-6,900
Intake Duration at 050 inch Lift:256
Exhaust Duration at 050 inch Lift:262
Duration at 050 inch Lift:256 int./262 exh.
Advertised Intake Duration:294
Advertised Exhaust Duration:300
Advertised Duration:294 int./300 exh.
Intake Valve Lift with Factory Rocker Arm Ratio:0.528 in.
Exhaust Valve Lift with Factory Rocker Arm Ratio:0.545 in.
Valve Lift with Factory Rocker Arm Ratio:0.528 int./0.545 exh.
Lobe Separation (degrees):114
Grind Number:294SF
Camshaft Manufacturers Description:
Headers, dual exhaust, large cfm carburetor, performance ignition and increased compression of 10.25:1 and above is required. Cylinder head modifications would be beneficial. Use with automatic transmission with high stall torque converter or manual transmission. Close attention to proper ring and pinion gear set and tire diameter is imperative.

Lifters, Crower "Cool face" #84326X980
Jaguar IRS Rear, 3.92 gears and Power-Loc, rebuilt by Hamilton Automotive.
Transmission, rebuilt Muncie M20
Overdrive, Gear Vendors.
Brakes, four wheel disc.
Wilwwod rear calipers, stock front, for now.
Front body, Stock appearance fiberglass by U.S Body.
One-piece tilt with a forward hinging functional 2" cowl induction hood.
Radiator, Aluminum.

Yep, I've been spending money.
Probably a lot closer to this forums title now, but still and always running 15" wheels.

[RichardSIA]

Heads are finally on the block.
Beginning to look like an engine.
Have to order pushrods to proceed further.