[1930u]

Are there any old school top fuel or cackle fest guys on the forum? I am trying to find out what the specifiactions were for lets say a 392 Hemi-417 Donovan top fuel motor in the 60's. Things like compression, cam specs., blower boost, lbs. fuel, etc...

Thanks

Ps. You don't want to know.

[bentwings]

Well not much to go on but we ran about 40 over on the blower with a flat Gilmer belt. 57 1/2 in belt. Sometimes the next longer belt with a blower spacer. 354 head and intake spacers. 354's were supposed to flow better. Stock oil pump with 100 psi spring. Oil restrictor plug. Remote oil filter. Swinging oil pan pickup.

About .06 to .100 out on the pistons. I think the fuel strokers were about the same but down the hole. O-ringed block. Filled block. Water inthe heads only. Just basic pocket porting. There were a couple places that made ported heads but the heads cracked easily so they were an expensive throw away item.

Blank in the hat for a main jet. There wasn't much choice for fuel pumps early on. Enderle or Hilborn I think a 150 Hilborn was what we ran. The pump overdrive didn't arrive untill the late 60's or early 70's. 80-90 % nitro. 60 in the mag. Cerillo mag was the rule.

Flat tappet cams for the fuel guys. I think about .550 was the limit. Stainless valves 2x2. 11/32 stems for lighter weight. Donovan or Milodon gear drive. Adjustable push rods. Needed 2 long 3/8 open end wrenches for adjusting.

Blocks and heads did not last long so we also were always on the lookout for a donor car for a 392. They often could be had for $25-50.

That's it for starters.

[1930u]

Thanks for the info. So the engines really were not that wild spec. wise. I was assuming they has .800 lift cams radically cut pistons, etc. Would a 40% overdriven blower equal about 50 pounds of boost? Also what did they mix the nitro with... gasoline? The raw power was made by lots of nitro fuel and blower pressure.

Thanks again.

[bentwings]

On a good day with a good blower you could get 24# boost on the 454 (392 + 1/2 stroke).

Nitro is mixed with alcohol. A hydrometer calibrated for nitro % is used to measure the fuel mix. There is also a temperature compensation. When you play with fire you need the right tools. haha There were a number of "trick" additives tried. These for the most part caused more problems than they were worth. Most were outright dangerous.....some caused the nitro to become shock sensitive. There were a number of mysterious explosions and fires. Lots of nitro and ???? additives were poured on the ground after runs. Finally NHRA banned all additives. they even banned nitro for a while and we all were really upset. Trying to go fast on gass really sucked. I burned more pistons on gas than I ever did on nitro.

actually cams were very long duration 285-295 at .050 lift. just as today. Valve springs were the limiting factor.

[1BAD80]

We just started racing in the Nostalgia Nitro Funny Car Class last year.
Only been to 3 race's and we won 2 of them.
NHRA has the rules for the motors & chassis.

Below sites has some info you want and a view of our car,

http://www.deepstage.net/NFCA/rules.htm

http://www.nostalgiafunnycarnews.com...read.php?t=876

http://rides.webshots.com/album/551835267egVdPz

[bentwings]

Nice car. How about some motor spec. What kind of times are y'all running??

My son is on the Telstar team. Does all the motor, clutch and mechanical stuff. They just put together a new motor due to show next week. They have run 6.07 217. 1/4 mile. I don't think they have run 1000 feet yet.

Around '72-73 I ran a TF FC called 30 Below. We ran almost exclusively match races back in the heyday. 6.70 217. Stock bore and stroke 426 and 6-71 stock steel block and heads, flat tappet fuel cam. I also worked for Shifsky and Halliday at their shops and at times on their cars. I also ran a very successful alcohol FC called Foxy Lady. We also ran the match race and show circuits. Ran with lots of the cars from the Chicago area and KC area.