Need for more speed

2

28 fast faton

Member
Hello. I have 28 Phaeton wirh a 5.5 head and high speed gears but I can t seem to get over 50mph ( I don t need to most of the time but feel I should be able to) Just did timing, new points, condenser, gapped plugs, cleaned all ignition contacts, checked compression (85 in all), cleaned carb, adjusted toe on front end, and more. It has never gone any faster even when everything was new after rebuild. I hesr of guys get 65mph out of theirs. What could I be missing?
Thanks.
 
Check your speedo with a GPS. What gear ratio is in the rear end, it's possibly too high for the power you have. What did you set the timing at? Too much or too little can affect top speed. 26 degrees BTDC is probably about right.
 
My car is stock, and I've hit 70 mph on the interstate, not for a long time but with the short wheelbase and narrow tires, it rides squirrelly. The best ride is around 45-50 mph, even on dirt roads.
 
Worn cam lobes , or timing 1 tooth out ?? Just had this on an import. Fitted a Brierley cam , correctly, now it fly,s 2nd time have found this , 1 part thats often overlooked, Thanks Jim top guy .
 
All of the above.

To check the valve timing, rotate the engine so that the timing pin in in the detent in the cam. Then take #4 plug out and peak in there with a light or borescope to check that both valves are very slightly open and that the piston is at the top. If you rock your engine back and forth you can verify that the both valves are transitioning from open to closed and closed to open. The exhaust valve will be closing the the intake valve will be opening. Make sure the piston is at the very top when you check the valves. You can check the piston by rocking the engine back and forth while watching it.

If this is not the case then take the cam gear covers off and move the cam gear one tooth in the direction to fix the timing. If the valve timing is late advance the cam gear one tooth counter clockwise. Or if early, one tooth clockwise. Then recheck and make further adjustments if needed.

If you don't mind taking the trouble, this is all done easier with the head off.
 
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If you are going by the speedometer, it could be reading wrong. Of my 3 cars, the 28 reads about 5mph too slow, the speedometer was rebuilt about 30 years ago. My 30 reads about 5-7mph too fast. I changed the drive gear and got a rebuilt speedometer 3 years ago. My 31 reads about 2-3 mph off and I am good with that. All of this is based on an app called Speedometer. I would check that before I dug into too much else.
 

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jb-ob said:
You are dragging a tent behind you !

The car world is full of story tellers.
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My father used to to tell me there are two things men lie about, their gas mileage and the women they have attracted.
I’ll add a third. Model A owners top speed.
 
Jack each wheel up and spin the wheel. Will it spin for 30 sec ? If not then your brakes are rubbing.
With correct tire pressure you should be able to push the A by yourself easily.
 
Different set-ups obviously produce different results. I wanted to be easy on the engine and drive 55mph when I needed to. I have a 5.5 Snyder's head, a B cam, a B carb, and a Mitchell overdrive. At 55 mph the engines turns at a comfy 1800-1900 rpm. I believe rear end is a 3.27.
 
My stock car will do over 65 but it wasn’t always that way.
Originally after restoration ( professional engine rebuild) and careful breaking in 50-52 was all it would do.
I preparation for a long drive to a national show I figured on checking the bearing clearance and found the rear main cap babbitt coming apart,the valve seats had been ground deep into the block and wear on the camshaft lobes so the mains got repoured valve seats installed and a later production replacement Ford cam.
Top speed became 67, fuel mileage went from 12-15 to23

If you use a cam designed for high power at high rpm and have a gear ratio that makes the engine not able to get into that rpm range the performance will suffer,
 
Kurt,

The wear on the cam would be a big cause of poor performance before the rebuild. It was probably a poor cam profile too. The seats being ground deep would restrict flow so that was a significant contributing factor. The original "professional" rebuilder did not know what he was doing.
 
nkaminar said:
Kurt,

The wear on the cam would be a big cause of poor performance before the rebuild. It was probably a poor cam profile too. The seats being ground deep would restrict flow so that was a significant contributing factor. The original "professional" rebuilder did not know what he was doing.
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My first thought too.
 
10 years after my rebuild I got to look at 2 other short blocks that they rebuilt.
The first one still had the packing in the oil holes even though they were drilled.
The second one hadn’t had the holes even drilled,
One of the things I learned doing the restoration is that I could screw it up 3 times for what it cost to pay someone else to screw it up.
 
I once had a Model T w/a "rebuilt" engine, seemed to run OK but couldn't get a smooth idle. Suspected, then replaced camshaft. That cured it.
 
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