1961 Thunderbird 390...

[WConley]

I've heard that sound - hair raising!  It was a friend's 427 which he put together.  He added the old spacer to the new chain sprocket, even though the new one had a spacer built in.  Same result as your pictures.

I bet it was bad inside that closed room.  Detonation inside a dyno cell is enough to make you want to run away.

[My427stang]

Flanged cam and the right timing set, or two cam retainer bolts and a cam retainer...if the original builder did EITHER it’d be running. Poor engine, glad to see it will be fixed

[WerbyFord]

WerbyFord do you know how much a t bird 3x2 intake gives up to a full size car 3x2 setup.I think it is flat and dont have a rise front to back i had one years ago and sold it to the t bird store (now npd).I know it had a fitting under the center carb for power brakes.Not much i am sure but some i would think.

Wayne,
A very good question. I can only find 2 dyno tests of the BIRD 6v intake in the Gonkulator database.
The Gonkulator's intake model says about 5hp less with the BIRD intake at the ~350hp level, and the two dyno tests are consistent with that though this is not definitive.

So the 390/340-6v M-Bird Gonkulates at 318hp with the Ford-6v intake, and 315hp with the Bird-6v intake.
About a wheel well difference in the 1/4 mile.

The "M" Bird comes really close to its 340hp rating if I Gonkulate it with the Ford-6v intake and 390HiPo shorty iron, neither of which will fit in the Bird. I wonder if that's how it got the 340hp rating, and was then "de-tuned" to fit in the car!

[blykins]

So as an afterthought, this little engine should have been a nice little piece for the guy.  Not optimal, but just a typical 390 rebuild. 

Some of the parts that we were guessing at, at the beginning of the thread have been brought to light since I've been doing a tear down.  It's got H304P pistons, .030" over, and about .030" down.  The cam is a CWC core, EP19 grind.  I think that's a factory replacement camshaft from Sealed Power. 

The hone job looks like it was done with an egg beater and I could tell it was not torque plate honed as it's showing some shadows and the bores were pretty round/straight with the heads off. 

I really wish we could have dyno'd it.  I love before and after tests.  It just wasn't in the cards. 

[Royce]

Werby, Did you have my Tbird 6v test in your data base.  IIRC it made 340 horse and 440 torque with dyno headers.  I substituted a Crane HMV 260 cam for the original..

[pbf777]

Flanged cam and the right timing set, or two cam retainer bolts and a cam retainer...if the original builder did EITHER it’d be running.

     
     The earlier FE's utilized a camshaft with a thrust face flange facing rearward on the first journal, this contacting the machined finish on the block face, with a thrust preload spring and washer/"button" acting against the timing cover, which of early examples was of steel not aluminum.

     The earlier blocks can be converted for the later style thrust-plate use camshaft applications readily with the thread-tapping of two of the located oiling gallery passages currently stuffed with cup-plugs. And note as stated previously, that the later timing gear & chain set will also be required.       

     Scott.

[My427stang]

Flanged cam and the right timing set, or two cam retainer bolts and a cam retainer...if the original builder did EITHER it’d be running.

     
     The earlier FE's utilized a camshaft with a thrust face flange facing rearward on the first journal, this contacting the machined finish on the block face, with a thrust preload spring and washer/"button" acting against the timing cover, which of early examples was of steel not aluminum.

     The earlier blocks can be converted for the later style thrust-plate use camshaft applications readily with the thread-tapping of two of the located oiling gallery passages currently stuffed with cup-plugs. And note as stated previously, that the later timing gear & chain set will also be required.       

     Scott.

Scott, aren't we saying the same thing? 

He had a late cam, and a late timing set, with an early spring button, but no cam retainer.  Two things that the LAST builder (just want to make it clear it wasn't Brent LOL) could have done

1 - Use the right cam, but also would need the right timing set and the spring button
2 - Ditch the button, use the parts he had, and add a cam retainer and two bolts (the right thing to do)

I can only imagine the noise, even first start, when the lifters were pushing back on the "next" lone as the button tried to send it to the back of the block

[KsHighboy]

Is that common for the H304p piston to be that far down? I thought the 304 was closer than that. To get zero deck with a 304 would require an excessive amount of cutting the deck wouldn't it? Or is there a better piston to use in a 390 to get it closer to the top?

[WerbyFord]

Werby, Did you have my Tbird 6v test in your data base.  IIRC it made 340 horse and 440 torque with dyno headers.  I substituted a Crane HMV 260 cam for the original..

Royce,
Yes I've got that one thanks.
For a minute I was hoping we could make it 3 Bird-6v dyno tests instead of 2, but not to be.

[pbf777]

   
Scott, aren't we saying the same thing? 

     I'm not at odds with anything you stated.  I just wanted to add to your statement, as yours was clear for those who are familiar, but for others whom might be unknowing but interested I wished to just add some to the picture.     

     Scott.

[My427stang]

   
Scott, aren't we saying the same thing? 

     I'm not at odds with anything you stated.  I just wanted to add to your statement, as yours was clear for those who are familiar, but for others whom might be unknowing but interested I wished to just add some to the picture.     

     Scott.

No worries with me!

Is that common for the H304p piston to be that far down? I thought the 304 was closer than that. To get zero deck with a 304 would require an excessive amount of cutting the deck wouldn't it? Or is there a better piston to use in a 390 to get it closer to the top?

1.759 pin height = 10.139 stack, .031 below on an uncut block

L2291 TRW/Speedpro forged are a nice choice at 1.78

[KsHighboy]

Thanks Ross.

Question since you brought up the 2291. My 390 is a .060 over with 2291's. I'm running a cam research. 218@50 int 225@050 exh. WITH A .530 lift. Head gasket is just a blue fellow and I don't know what tr he thickness is. Heads are C8Ae. When run a compression test I only get about 145-150psi. Is that what I should expect from this  combination?

[WerbyFord]

Thanks Ross.

Question since you brought up the 2291. My 390 is a .060 over with 2291's. I'm running a cam research. 218@50 int 225@050 exh. WITH A .530 lift. Head gasket is just a blue fellow and I don't know what tr he thickness is. Heads are C8Ae. When run a compression test I only get about 145-150psi. Is that what I should expect from this  combination?

KS,
It would also help to know the LSA and advance or ICL of the cam. I assumed LSA=110 and ICL=106 which is 4 advanced. Given that, and assuming a .040 gasket, my Compressolator gets:
9.7 CR
90 Octane requirement (assuming aluminum intake and blocked heat crossover, no cold air, 180F water)
178 psi compression, give or take 20 psi, that's as good as the model is.
Are you measuring hot or cold?
Is the carb (what carb is on there?) blocked open?
I usually let the gauge see 6 "hits" for consistency.

[KsHighboy]

Webby, you are correct on the separation and C/L. Its been awhile since I checked it but I believe it was cold and no the carb was not open.

[My427stang]

Webby, you are correct on the separation and C/L. Its been awhile since I checked it but I believe it was cold and no the carb was not open.

Sounds ballpark to me, a L2291 with a .053 Felpro and a .010 cut deck, C8s, would be around 9.25-9.40 static compression

Can't really calculate without advertised (.006) duration, but assuming around 272 adv, I would say you are in the ballpark, especially if throttle closed