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By Florida_Phil - 7 Years Ago
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I am in the process of swapping the heads on my 1955 TBird. The engine is the stock '55 292 .040 over and it runs well. I have a rebuilt set of 1957 G Heads, '57 high ratio rockers with the longer push rods and a 1957 "D' code iron intake with a new Holley 4 barrel. I also have the a set of '57 exhaust manifolds off a passenger car.
When I removed the '55 small port heads, they had metal oil baffles under the rocker stands. I worked on a number of Y blocks back in the day and have never seen them before. I assume I should not use them on the '57 heads and rockers? There seems to be a number of thoughts on this. I plan to close the end of the oil drip tubes to pressurize the rockers.
I am using Fel Pro blue head gaskets on the '57 heads. What torque readings should I use? Should I re-torque the heads later?
I looked at the G heads and the ports are much wider. The valves are also bigger. It will be interesting to see what difference these heads make.
To be honest, I do not see much difference in the '55 TBird Exhaust manifolds and the '57 passenger car manifolds. I'm not sure they will fit my TBird and from the looks of them I don't think there is that much performance to be gained. Thanks for you input.
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By Ted - 7 Years Ago
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The ’57 and up exhaust manifolds do exhibit an increase in both HP and TQ over the ’56 and earlier exhaust manifolds. The difference in numbers are not big but when coupled with a better flowing intake manifold, higher lift rockers, big valve heads, and the better 1957 camshaft, the difference in performance is significant. Here’s the link to the dyno results for the various exhausts on the Y.
http://forums.y-blocksforever.com/FindPost99070.aspx
The Thunderbird drivers’ side exhaust manifold is different from that on a passenger car. The opening for the exhaust pipe that connects to it is cocked at different angles on that particular side which is only a problem if trying to use the original Thunderbird exhaust pipe on that side.
Assuming you have grade eight head bolts, then 70 lbs/ft for the short bolts and 75 lbs/ft for the long bolts would be good torque values to target for. Fel-Pro head gaskets are noted for seeping coolant at the lower edges of the heads so be forewarned on this. I have much better luck with the Best Gasket brand regarding those pesky coolant leaks. If your car currently has steel shim head gaskets, then be aware of a slight drop in compression ratio when going with a composition head gasket.
I like to retain the diamond shaped oil baffles under the rockers when I have them. They do help to keep some of the excess oil from the guides and if you are pressurizing the rockers, then there will be more oil at the guides versus the excess going to the overflow tubes.
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By Florida_Phil - 7 Years Ago
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Thank you so much for your help. I will retain the oil baffles. I was aware of the issue with the TBird exhaust manifolds vs. the passenger car. I will still be running the 55 camshaft for now. I don't want to pull the motor yet and hanging upside down like a bat to change the lifters is not by best position. After I finish swapping the heads, I'll post my observations on the change. Swapping out the intake, carb and distributor really woke up this old dog. We'll see what the head swap does.
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By slumlord444 - 7 Years Ago
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There shoud be a noticable difference. Heads make the engine.
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By speedpro56 - 7 Years Ago
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Ted is right about the Fel-Pro gasket leaks. Best gaskets really are the best so I wouldn't waste my time with the fel-Pro brand at all, been there done that.
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By Florida_Phil - 7 Years Ago
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Should I remove or disable the exhaust valve?
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By Ted - 7 Years Ago
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Florida_Phil (10/9/2017)
Should I remove or disable the exhaust valve?
Definitely consider removing the ‘exhaust valve’ from the backside of the exhaust manifold as there’s still a flow restriction if simply disabling it.
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By oldcarmark - 7 Years Ago
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quote]Ted (10/9/2017)
Florida_Phil (10/9/2017)
Should I remove or disable the exhaust valve?Definitely consider removing the ‘exhaust valve’ from the backside of the exhaust manifold as there’s still a flow restriction if simply disabling it.
"Exhaust Valve" is the Heat Riser? Not familiar with the "Exhaust Valve" Description. You can buy Spacer to replace Heat Riser from most Companies like Mac's and Tee-Bird.. When You replaced the Carb did You ad a Phenolic Spacer under Carb?
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By GREENBIRD56 - 7 Years Ago
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Here is the list of manifolds and where they were found -
Hunt down the RH '57 (EDB9430A) if you can - it is a match to the ECJ on the left of the T-bird.
This set was "Jet-Hot" coated - makes a drastic difference in underhood temperatures.
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By Florida_Phil - 7 Years Ago
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I had to go to NPD this morning to buy a different temp sender fitting and I bought an exhaust valve spacer to replace the flapper. In Florida we don't have problems getting our engines to warm up. I have never used a choke.
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By Florida_Phil - 7 Years Ago
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I have everything back together now. I need to connect the exhaust pipes and fill the radiator with anti freeze, but I should have the engine fired by this afternoon. The car now has a 1955 292 .040 short block with 1957 heads, rockers, push rods, intake, Holley carb and distributor. The cam has not been changed. I used the oil baffles from my 1955 heads. The exhaust manifolds are stock 1955 TBird. When I adjusted the valves, I had to screw down the rocker adjustment screws pretty far. This surprised me as I am using the heads, rockers, stands and push rods from the same '57 engine. I think the '55 oil baffles raised the stands a bit. The rocker adjusters are not bottomed out, but it took a lot of turns to get them adjusted. From what I can tell the rocker stands are the same height up or down. My shop manual says there aren't, but the Internet says differently. Should I have used the '55 push rods?
Anyway, I'll post again when the car starts and drives. Hopefully soon.
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By Ted - 7 Years Ago
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Sounds like you needed longer pushrods if retaining the valve spring baffles. As long as the adjusting screws are still tight in the rockers and there is still some adjustment remaining you should be good to go.
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By Florida_Phil - 7 Years Ago
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Thanks for the quick reply. We are so lucky to have someone on this forum with your experience. Unfortunately, most Y block gurus are long gone. You're keeping the flame alive.
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By Florida_Phil - 7 Years Ago
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I set the valves at .019 and the motor fired right up with no issues. I brought the engine up to operating temperature and checked the head bolt torque. The head bolts were spot on. No coolant leaks so far. There is plenty of oil in the top of the heads, so the pressurized shafts are working. I also removed the passenger side exhaust flapper and replaced it with a straight through part. I don't have time for a test drive right now, but the engine sounds much stronger. The only real issue I had making this swap was the temp sender fitting in the driver side head. NPD sells both fittings. They are near me, so it worked out.
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By charliemccraney - 7 Years Ago
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Adding anything that acts as a spacer under the rocker stands, that was not originally used, can have a significant effect on the required pushrod length. The change in adjuster screw positioning required will always be greater than the thickness of the spacer because the adjuster screw rotates away from the pushrod as the stand height is increased. So hypothetically, a .030" change in stand height might require a .040-.045" change in adjuster screw position.
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By Florida_Phil - 7 Years Ago
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Makes sense. I have never seen the oil baffle plates before. Probably because I've never worked on a 1955 Y Block before. All looks good to me. I guess I could pull the rocker shafts and use the '55 push rods which are suppose to be longer. Now we know why.
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By Florida_Phil - 7 Years Ago
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Went for my first drive with the new '57 top end. The car now runs like the Y Blocks I remembered. You can feel that first gear torque and the engine pulls like it should. I'm pretty sure this little TBird would have given a few 283s a run back in the day. I'm starting to worry a little about the brakes. Those drums just aren't cutting it.
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By 2721955meteor - 7 Years Ago
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Florida_Phil (10/8/2017)
I am in the process of swapping the heads on my 1955 TBird. The engine is the stock '55 292 .040 over and it runs well. I have a rebuilt set of 1957 G Heads, '57 high ratio rockers with the longer push rods and a 1957 "D' code iron intake with a new Holley 4 barrel. I also have the a set of '57 exhaust manifolds off a passenger car. When I removed the '55 small port heads, they had metal oil baffles under the rocker stands. I worked on a number of Y blocks back in the day and have never seen them before. I assume I should not use them on the '57 heads and rockers? There seems to be a number of thoughts on this. I plan to close the end of the oil drip tubes to pressurize the rockers. I am using Fel Pro blue head gaskets on the '57 heads. What torque readings should I use? Should I re-torque the heads later? I looked at the G heads and the ports are much wider. The valves are also bigger. It will be interesting to see what difference these heads make. To be honest, I do not see much difference in the '55 TBird Exhaust manifolds and the '57 passenger car manifolds. I'm not sure they will fit my TBird and from the looks of them I don't think there is that much performance to be gained. Thanks for you input. gaskets have used felpro gaskets recently with no issues, i spray high tack sealer on both sides,clip the pushrod side to copy best gaskets, use grad 8 cat head bolts. also remove tin flow spacers frome rocker stands a way to compensate for thicker head gaskets.tho my exp is limited to 3engines this year,so not the same history as ted by any means
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By MoonShadow - 7 Years Ago
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And this is how it begins. Little better horsepower, little more pull in first, little more looking for scrubs to embarrass, little more brakes (yeah, discs that's the ticket). Your dormant Y-Block genes are coming awake! Get ready for a great ride!
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By oldcarmark - 7 Years Ago
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Florida_Phil (10/10/2017)
Went for my first drive with the new '57 top end. The car now runs like the Y Blocks I remembered. You can feel that first gear torque and the engine pulls like it should. I'm pretty sure this little TBird would have given a few 283s a run back in the day. I'm starting to worry a little about the brakes. Those drums just aren't cutting it.
Nice to see a Picture of your Ride. Looks great. Power Disc Brakes are the way to go. You can expect some negative Comments from some Members on this Site in regards to upgrading your Brakes. I like to Stop NOW which is why I put Discs on mine.
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By Florida_Phil - 7 Years Ago
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I started with an unmolested car, so I would prefer to keep everything as stock as possible. I have kept all the original parts just in case someone wants to return it to stock. So far I replaced all the shoes, the two back brake cylinders and all hoses. I just ordered the front cylinders and a new master cylinder. I'll install them and see if there is any improvement. It's hard to tell if the brakes are really that bad or if I'm just used to modern brakes. The car stops, but not with authority. It's not dangerous, but definitely not what you want in today's traffic. If I have to, I'll switch to disks.
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By DryLakesRacer - 7 Years Ago
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If you would like better brakes consider a vacuum assist booster like one that would be added at the dealer. I see from your photo that one is not there now on your left inner fender. It's the next thing I'm doing to my 56 Victoria.
Also I've added lash caps to my valves many times but on the stock Y, not sure if the valve is above the keeper enough but it will allow to get your valve geometry back closer. Valve/rocker geometry is very important for valve tip, rocker arm tip life, and getting full lift from your rocker arm ratio. Nice 55 Thunderbird..
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By Florida_Phil - 7 Years Ago
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My valve adjustment screws are about 3-4 full turns from being bottomed out. I have plenty of adjustment left, just not in the middle of the screw. I'm thinking about removing the oil baffle plates to see if I can get it somewhere back to normal. Like I said before, I have never run them before.
One of my books says the '55 push rods are longer than the '57. I'm not sure about that. I'll pull one and check. If this is true I could swap the '55 push rods back in to get the adjusters to center.
The stock '55 cam seems to be OK for now. The motor has lots of torque and revs to 5,000 with no problem. This is a street car and it won't see any revs over that. One day I may swap out the cam, but for now I'm satisfied with the performance. That probably won't last long....
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By Florida_Phil - 7 Years Ago
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I pulled the rockers back off and checked the push rods. The '55 push rods are a lot longer. I swapped out the '57 push rods with the '55 push rods and readjusted the valves. The geometry came back to normal with the rocker adjusting screws in the middle. My guess is the longer rods push rods are there to make up for oil baffle plate thickness. Another day another lesson learned.
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By charliemccraney - 7 Years Ago
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It's a good guess. Long pushrods were used again in '60-'64, without baffles, so there may be something else going on. The difference in pushrod length is about 3/16", which seems like far more than would be required for only a baffle that is maybe 1/32"-3/64" thick. I've never compared heads in that area to see why. My guess is more to do with a different shaft mounting pad height, although the baffles should definitely come into play on the earlier heads.
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By Florida_Phil - 7 Years Ago
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I think you are right. After installing the '55 push rods things still didn't seem quite right, so I removed the baffles, put the '57 push rods back in and readjusted the valves. The top end is now all 1957 from the same motor. The motor runs fine and think this saga is over for now. Swapping parts from different years is always troublesome. Thanks for the input.
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