TF engine blocks (1 Viewer)
- Thread starter flapjack
- Start date
AJPE Blocks
Shannon,
I thought the TFX block, while originally a Rodeck design (not sure about this), is now manufactured by AJPE...
Bill
Nitro Member
I must be getting old.
Back in my days, we had Cast Iron, Milodon, Donovan or Black.
You're not "old." In my day, there were NO aftermarket engine block suppliers; we had Chrysler Hemis, Oldsmobiles, Pontiacs, Fords, Chevys, and a few DeSotos...
You actually had a brand to root for.
The stands were full.
Bill, in Conway, Arkansas
Silly Savage
Nitro Member
Those went away long ago...
Silly Savage
Nitro Member
That is also my understanding
I can tell you from all my research all I have come across is TFX, BAE, AJ 500, and the Ford 500. I also come across teams in my research that have different displacements. Can someone explain the difference of the block and the possible dispacement differences? For example I've seen some TF teams have a TFX 500, TFX 496, TFX 498 on entry lists, same for displacement variances for BAE.
Silly Savage
Nitro Member
I wouldn't put much weight on what is listed on their entry list from race to race. Depends on bore and stroke of their current combo.
The stroke on the most of these motors, as far as I know, is 4.5 inches, and is called the "three quarters stroker", so named because it is three quarters of inch more stroke than the stock 426 HEMI stroke of 3.75 inches. There is also a 5/8 stroker, but I am not sure if that is used now-a-days.
The different displacements are due to different bore sizes. The 496 ci displacement has a bore size of approximately 4.1875 inches. Actually, the displacement is slightly less than 496 cubic inches, but it's close enough to call it 496 inches. I could work out for the bore size used in a 498ci and 500ci engine, but I am too lazy.
So for instance, a team running a TFX 500 and a team running TFX 496 is still making the same horsepower and it's just all about what specific combo worked for them individually?
Nitrohelper
Nitro Member
They are all now 4.187 X 4.500 = 495.7
The variances comes from the person filling out the entry form...
The rule limit is 500 ci ,so that's what some folks write down...
A few guys ran 4.250 X 4.375 = 496.5
One team ran 4.315 X 4.250 = 497.2
Thanks. So in theory forgive me because I know nothing about this other than a question, could a team find a way of getting bore and stroke coming out to exactly 500 or as close to end up having an edge? Can performance advantage now come down to bore and stroke as close to 500? I mean I have no idea what 4.3 cubic inches could mean to a dragster.
Only when you take everything else away in an attempt to slow them down!!!
waco flash
Nitro Member
CN Billet blocks also makes TF blocks,made 2 for Prudhomme before he retired from the class.
Nitrohelper
Nitro Member
Certainly means nothing with a supercharged Nitro burning engine...
Pistons are custom made to the purchaser's specs, it would be easy to make the engine 500.0 ci.
But isn't worth the chance of it being field measured at 500.2 and then have NHRA disqualify the car...
4.205 X 4.500 = 499.9 --- be off by .001 --- then 4.206 X 4.500 = 500.2
nedannouncer
Nitro Member
Eddie Hill was one of the last guys to have big success with the 5/8 combo as I remember it. Years ago I wrote a story for Comp Plus and interviewed both Eddie Hill and Dale Armstrong talking about top fuel engines (yes it was BOSS!).
Hill's logic was that filling the "short fat" cylinder of the 5/8 engine's bigger bore was more efficient than trying to fill the "longer taller" 3/4 combo's cylinder.
Armstrong talked about an experimental "1/2" stroker they tried in Bernstein's car during his days of experimentation. In testing it went 60 feet before blowing the front right section of the block completely apart. They shelved that one.
Brian
Hill's logic was that filling the "short fat" cylinder of the 5/8 engine's bigger bore was more efficient than trying to fill the "longer taller" 3/4 combo's cylinder.
Armstrong talked about an experimental "1/2" stroker they tried in Bernstein's car during his days of experimentation. In testing it went 60 feet before blowing the front right section of the block completely apart. They shelved that one.
Brian
