Randy G.

Man, I got some grey hair out of this.

As you remember, I picked up the '62 in a round about way, but it came from the family of a guy who was restoring it 15 years ago but died before he finished it. It had brand new 25+ year old tires on it, brand new (still looks new) Al Knoch interior, new brakes, etc., etc. Knowing it needs sorting out I decided to tackle it.

Once I put new tires on it I cleaned everything, flushed the radiator, added new anti freeze, flushed the fuel tank, replaced some rubber stuff like fuel lines, water hoses, vacuum hoses, then went through the brakes even though they are new and solved a left rear axle bearing leak, did a front end alignment, checked every suspension and steering nut and bold (some were really loose) I finally get to drive it only to have it overheat at idle to 240* within a few minutes.

The fun is spelled out in nearly 200 posts in this thread linked below which includes 3 thermostats, no thermostat, new Dewitt's restoration radiator, extra fans, new variety of fans, new fan clutch, locked up the fan clutch, new water pump, timing, vacuum advance, tested the cooling system with a test kit from Napa for exhaust gasses in the cooling system, spraying water on the radiator, 100% distilled water, night time driving at 65 degrees, and finally pulling the heads off and finding some sort of black sand tar base crap plugging up most of the water passages between the heads and block at the head gaskets. That stuff was everywhere. I cleaned it out and it was slightly better but would still overheat at idle, in traffic or in fast food drive-throughs.

https://www.corvetteforum.com/forums...n-the-fwy.html

Like I said I tested the cooling system for exhaust gases with a kit I got from Napa Auto Parts before I pulled the heads and it was fine. Tomorrow I was planning on ordering a crate motor so I decided "What the heck" let's check it one more time just to see if anything has changed. What prompted this was the sweet burning anti-freeze/chocolate/puking water smell in the car (even though it has 100% distilled water in it and it wasn't puking) when it got around 220* Friday on my way to Ruby's Diner in Whittier. So this afternoon I drove it around for about 10 minutes to get it up to temperature and did the test. The chemical is supposed to stay blue if everything is fine and there are no leaks or turn yellow if there is exhaust gas in the radiator coolant. The instructions say to pump the bulb for 1 minute over where the radiator cap sits to draw air from the cooling system. I pumped it about 5 times (10 seconds) and it turned yellow.

I used Fel Pro blue perma torque head gaskets on it so I know they aren't leaking. The oil looks brand new so there isn't anything going from the cooling system to the oil pan. There is no water or steam coming out of the exhaust pipes. There is definitely a crack, which I would guess is a head in the combustion chamber or up in the exhaust port. Might be a crack near the valve seat. There was no evidence anywhere of rust or cracks by observation when I took it apart a few weeks ago. My guess is all that black tar sandy looking crap was someone attempt to fix it, but it ended up plugging everything.

Since it's not the original engine and is a "Targetmaster 350 'Hencho de Mexico'" as indicated in the head castings I'm going to order a BluePrint 383 through Summit. They have one in stock in Nevada so I should have it Tuesday. I was going to order a 290 HP/350 from GMPP but I think the aluminum heads on the BluePrint will help to keep it cool, besides the fact that the BP is 430 hp, 450 ft/lbs of torque. It's this one.

http://www.summitracing.com/parts/ml...3ct1/overview/

59BlueSilver

I guess I'm wondering why you just didn't replace the head (s)?

tuxnharley

My guess is because its an opportunity to have "More Power"!

What do I win?

Randy G.

Because an early 1970's GM "Targetmaster" engine isn't worth cost of new head gaskets, let alone throwing more money at it by buying heads, etc.

Tuxnharley wins a free ride in it!

Westlotorn

I have a set of early 90's 350 heads, cast iron and low mileage factory heads.
I believe these would be 76cc heads standard head OEM for the 350 in those days.
If these match your engine I will donate them to your cause and meet you in S Cal to deliver them. I work down there often. You have been through enough and I appreciate your persistence working through your overheat issues.
If you want the new 383 for more power my heads will not help but if you wish to drive and enjoy your car they might and Free is hard to find in the market today.
(Donny Brass must have sparked this idea with his pay it forward work this week.)

Randy G.

That's very nice of you. I read this and wondered if they would work. Seems the angle of the center intake manifold bolts changed around 1988 and on. I have an Edelbrock performer manifold so they may not work.

I saw an explanation as to why exhaust gas getting into the cooling system around the heads causes it to overheat. Seems the gasses form air pockets in the heads and cuts off the cooling ability. It sure acts like it because while sitting still the temp rises slowly, but as soon as you touch the throttle the temp gauge immediately jumps 10 degrees.

ack fia

I have and have seen a number of 1962 Heads that were cast in 1961 (461X) that have small cracks between the valve seats in the middle. The cracks appear to be at the knit line and many cracks appear at the same place.

65tripleblack

If you would have followed my advice early on in that other thread you would have saved yourself a lot of headaches. That gas leak tester is hit and miss........doesn't always work.

You should have pressure tested those heads while you had them off as I recommended. But, then again, WTFDIK.

Westlotorn

The Heads changed in 96 when they went to Vortec heads. Up to 95 they have the old bolt pattern intake.

AZDoug

How do you pressure test heads?

Without a lot of specialized equipment, or jigs, block off plates and fixtures?

Doug

AZDoug

A side note, you absolutely need to do one of those block tester procedures outside, with the exhaust being blown downwind, as you can and will get a false reading doing it in a garage or if the wind is blowing the exh gasses back on to you

I had a head gasket leak once from a carb flooding issue.

The car didn't overheat but it puked coolant every time you shut it down.

Doug

BD104X

You bring them to a machine shop & say "Could you please pressure test these?"
Its money well spent, and a lot less than all of the other stuff the OP replaced.

cardo0

That was quite an experience with your cooling system but now u r an expert on cool problems and diagnoses now.

U will be happy with that stroker in your car. Im sure u will have more than enough power now to get u into trouble - your gonna want better brakes soon. FYI u need: This engine requires a 400ci weighted harmonic balancer, and late 350ci weighted flexplate/flywheel (one that fits your power glide and starter).
BluePrint Engines recommends a 2000-2400 rpm stall converter (that sounds pretty low but just what u need behind a PG trans). The dampner and flexplate u have on the car now wont work - just a heads up.

Yea my C3 still has the "Target" motor i bought it with. They were only $1000 25 years ago while still less than $1700 today and make good working truck motors but are limited for performance. For some reason the Hecho in Mexico casting on the block looks out of place on a corvette. I got $20 for the stock heads at a swapmeet and happy for that - nearly any head is an improvement to those. But now u will have a core sbc to rebuild as a ready spare for either of your vettes.

Congrats, thx for sharing and let us know how the new motor works out.

Randy G.

I know what you are saying and I agree (not on the WTFDIK part )

All the good machine shops around here have closed. Jay Steele owned Taylor Engine Rebuilding and he was the last holdout, but he passed away and the buyer lost it. Shipping the heads to someone to test them would have meant freight charges that exceeded the value of the heads. Besides, I like working on it because I need something to do and I don't like to just quit and go the easy route.

Most of what I did was to prep it for another engine anyway. My criteria when buying stuff like the radiator, fan and fan clutch, etc., was based on what was going to be done with an engine swap. The rest of what I did was just water down the driveway and labor.

The way the test kit tube seals against the neck of the expansion tank I would think it would be difficult to get a false positive reading. And like I said, I've "smelt that smell" in a car before.

I was actually thinking about it last night. Edelbrock makes an aluminum head in their E-Street series that is set up for hydraulic mechanical lifters, has similar combustion chamber volume, and one that is 10cc less which would bring the Targetmaster stock compression ratio from 8.5:1 to 9.5:1. My wife says forget it, the block might be cracked, too. Who knows, this engine may have originally been in a pickup truck that hit 260 degrees, pulled out, and somehow ended up in the '62.

The '62's have "air cooled" transmissions, so I would need to add a cooler to it since it doesn't have one with 2,500 stall converter. I also need to confirm that it has a 163 tooth flexplate. It has offset starter bolts which is typically a clue that it does. If they were aligned it would be 153.

When they went to the larger intake and exhaust valves on the small blocks they did crack through the adjoining seats. The crack would extend from inside the exhaust port, through the exhaust seat, then to the intake seat and on into the intake port, almost like a horseshoe.

GTOguy

Randy, I like your way of thinking and I feel that you really stuck with it and took all the right steps on this issue. Thanks for filling us in, and good luck with the new engine. I agree 100%: I would have nothing to do with your current targetmaster engine. Scrap it and install that 383!
Jeff

Stan's Customs

I like magnafluxing...it's not like pressure checking, but it's amazing how easily you can see cracks....and some cracks don't leak under all circumstances.

But you are right... machine shops are disappearing fast, and those that are left don't know what they are doing a lot of the time. I've had a couple of bad experiences in one of our local hole in the wall machine shops. I finally found a shop that does a lot of import and motorcycle machine work...to help with one mess I had to get redone.

It was a 3rd generation import machine shop...but after he looked at my pieces he decided to help me out (they consider old v-8 chevys to be archaic...and normally don't mess with them). Plus the other stuff pays more I'm sure.

Glad you have come to a conclusion on this...thanks for letting us know what you found. I'm thinking the Summit engine will be a hoot anyway...may all be for the good.

Happy trails...Stan

Randy G.

A friend of mine who is an outstanding machinist used to work for Ray Zeller at Downey Service Center and later went to work for Carol Shelby when he was in Torrance. He relocated to Redding years ago and now works for Automotive Associates. He actually taught automotive machine for a few years at the local community college. He was also my cylinder head guy on my TA/FC when we used to race (I retired from racing after winning the 2012 NHRA Winternationals). He called me yesterday and wanted to know if I ordered the crate motor yet. I told him "no". He told me from the beginning that while the Targetmasters were good engines they weren't good enough to ever consider rebuilding them. He said to "find a good crate motor with a warranty from a company that will stand behind it and don't look back." That's from a guy who earns a living in the automotive machine industry.

So, two minutes ago I just did.

Randy G.

And thank you!

Westlotorn

Your Target 350 is not a boat anchor. It is still a 350 Chevy. Granted it is low end but so were most 350's ever built. Cast Crank, sissy camshaft, but it is a 350 and can be rebuilt with no issues just like any other 350. Most 383's will have a cast crankshaft unless you buy the high end upgrade and then it is still most likely a Chinese knock off.

Enjoy your new engine, in my experience once you set your heart on something you are wasting money to do anything other than what is first on your list. I hope this one makes you smile and drive a lot more.

Randy G.

Someone I know from back in the day explained it like this. At the GM plant the blocks were cast, sonic tested and machined. After that they were checked. The good one's were sent to the Chevy car line and the bad one's were sent to become Targetmasters. The real bad one's who knows. The heads were considered to be average flowing for the choked down smog engine era. By today's standards they are poor at best.

For some reason it got hot enough somewhere during it's life to crack a head or the block. Once this happens you end up chasing your tail dealing with it. I will have the heads and block checked. It's not going in the trash.