QUESTION: Drag engines with no coolant?

Hi all,

This may be a stupid question, but one I have to ask nonetheless...

I know many drag cars don't run radiators or coolant as they are operational for such short periods of time, and I plan to do the same with my altered (please see my thread http://www.jalopyjournal.com/forum/showthread.php?t=375267).

We have no experience using an engine with no coolant and are unclear how it is done.

I have done a little research at the drags for a few years but can't get any solid answer. For example, some people have told me that they simply block off the inlet/outlets for the water jackets including the manifold, water pump etc. Others told me they simply filled the jackets up with concrete (!) and some have told me to use a heat resistant resin, but failed to specify what to use.

We'll be starting to run the car with the naturally aspirated 302 Windsor shown in the above thread. I've read that blown/injected cars simply flow huge amounts of fuel, thus the header flames of top fuel cars etc.

If anyone out there has experience with such engines, any advice would be greatly appreciated.

Thanks

Tarlo

 

Many of the A/ND dragsters don't use any coolant. The blocks are filled more for rigidity than anything else. The reason they can run without coolant is because they use alcohol and their fuel. The alcohol being sprayed thru injectors does it's own cooling, plus they use up quite a bit of it making a pass. I think trying to use gasoline in the same configuration would be almost impossible with all the heat generated. As far as a engine running nitro, they're like a grenade with the pin pulled on every run. They have so many seconds from start to finish to make a pass before the heat and pressure starts eating parts.

 

In my dragster 302 chevy, My block was filled for stability, and I did not run any coolant. alcohol was the fuel. I cranked it in the pits to get some heat in the eng, and was towed to the line,started eng, burnout, run, then made the turn off and found a out of the way to park, shut it down. .

 

Back in the'70s when I ran my FED in the enco rail class 350 chevy with carb and ran on pump gas I filled the block with a 50/50 mix of water and antifreeze, drained after each run let block cool and refill. Had a lot of time in between runs then and it was the way everybody done it.

 

Tarlo,

I have been following your build cloesly as I am also building a Topolino drag car. I will be running a Hilborn injected SBC and was planning on running gas. I have a lot of the same questions, can it (no radiator) be done on gas? How is the cooling system plumbed? Is there a slick way to flush the block between rounds?

I may end up swicthing over to alcohol due to lack of radiator/cooling system. I also like the wide tuning "window" of alcohol. The thing I don't like is having to drain and flush the fuel system after each day at the track.

While I've had some 10 second street cars, I'm a newbie to the whole dedicated drag, no cooling system, mechanical injection, on alcohol world.


Hopefully one of the experts will pipe in here and help a couple of brothers out!

Love the car! keep up the great work

 

what did you fill it with?

 

There are special block fillers for this purpose. Check www.hardblok.com

 

I remember seeing pictures of dragsters and they had the radiator hoses connected to some kind of tank in front of the engine. Some just had the inlets and outlets connected together with a hose.

I have not seen a dragster in a car magazine for a long time. Hot rod use have dragsters as featured articles.

Kids use to run flat heads around here without fans. They had good copper radiators that had a lot lower "r" value than aluminum. When i see somebody bragging about the aluminum radiator I think they must be reading too much advertising. Advertising sells.

At the first hot rod reunion in Bakersfield Ca. Ed Iskadarian (sp?) ran his old hot rod around the place without a fan belt to the water pumps.

The speed of the car will help cool the the engine some. On a regular day it takes a mile to get the car up to temperature.

Someone just told me they have rear engine dragsters these days. I plumb forgot about them.

 

The grout in the block is for rigidity , not cooling, Most times it is only filled to the welch plugs (frost plugs) or up to the water pump flanges.... some people still run coolant above the grout... for road racing and street use.
In a drag car it is common to go all the way to the deck......... some dry deck the block and still run coolant in the heads.

www.hardblok.com

I think you have to run alky rather than gas to make it work ,(runs a lot cooler) .
We ran a BBC in a Toppolino on gas for a few years,with coolant and then grouted the block after we changed to injected alcohol .... (actually we used Moroso grout). It never overheated, in fact it took some warming up first thing, but it stayed warm all day through the rounds ....ran faster when we had back to back runs and we thought it might be a bit too hot.....
The car started with a SBF ( 289) and ran high 10s. ( 10.9 breakout )
With a relatively mild 427 gas we ran in SuperGas..9.90, running alky we ran low 9s... never really pushed the tuneup before it was sold . New owner has it deep into the eights...and he is talking about blowers now.

 

were building a flatty FED and running water in the block. block ridgity is important with large overbores but keep in mind that rust never sleeps and if your engine lasts several years you mite start to have problems with cyl wall distortion from rust growing between the concrete and cylinders

 

Aww shit I just spent 40 minutes writing a response and then accidentally hit some combination of keys that deleted it - frickin' software programmers arghhh!

Short version:

Coolant nice, but unnecessary - moreso with Alcohol. Alcohol = good at the cost of a little more maintenance. Drain, blowout & oil your B/V and Fuel pump - daily - no matter what anyone else says. Alcohol is corrosive - the snake oils added to it are not an endall curall - do the work - you won't regret it, but you might regret not doing it.


We started with coolant (water - not antifreeze - water is safer during a mishap), but found it wasn't needed with our setup. I run the block dry now. We're injected on alcohol. We fire it in the lanes, pull the shutoff (about 1/2 way) to lean it down to build some heat - once to temp we shut it off and wait our turn. When they give us the heads up - we fire it with out assistance - if your system is in good shape - you'll only need to prime it once - the rest of your day it will fire without priming. We tow back, but could probably drive it - as it's not all that hot at the top end, but we keep it that way on purpose. I run a nearly stock motor - best so far 9.37 @ 142 - not bad for a home built motor built out of junk. Mechanical injection has it's challenges - lucky for us - there are people on the web that can straighten us out if we get confused.

I can't tell you to go gas or alky - but if you wanna go without a radiator - alky will make that easier.

 

Thanks for the advice guys, keep it coming!

At the moment we have a million things to think about, and as it's my car, I'm doing as much of the research as possible, so I like to think ahead as much as possible.

I'd be more than happy to run alky, I hate the smell of pump gas. I guess it will be a matter of what I can afford to do with the engine, though the whole point of using chassis saddles for engine mounts was to be able to have flexible options... blown alky big block? I'll keep dreaming!

 

I built a motor for a friend filled it half way up the water pump holes had a water pump and rad ran it on c14 would over heat had to be towed back to the pit and pushed to the staging lanes rebuilt the engine with higher compression switch to alky now drives to the staging lanes the engine temp drops as he's going down the strip stages at 200 finishes at 180 and drives back to the pits making back to back runs during eliminations
now he wants to remove the pump and rad

 

I run a 406 Chebby on methanol, It run's so cool I use a 1/4 turn valve connected to the pvc tube on a 3310. Open it up real lean to build heat ,most days it actually cools down some on the return road. Methanol is all I would ever use on a drag car.As far as your statement as to a big tuning window I have no idea where you got that ,it's either tuned or not.
By the way ,if it's tuned right there is no oil contamination ,I just open the lean out valve and build the temp up above 210 oil temp and put it on the trailer. Then open the caps on the valve covers and any moisture steams out . My oil stays good for a half season before I change it. Best of luck.
If you decide to run Methanol e-mail me and I might be able to give you some tips.

 

The short answer is that you run the engine for only a few seconds and shut it off before it melts. Top fuel cars get the engine rebuilt after every round anyway.

 

Many of the Gas Class cars back in the day ran a radiator without a water pump due to the Injection pump being run off the front cover/cam.
There was enough convection cooling to keep these gas motors (required by rules, no Methanol) cool enough. Many still did the drain and refill deal, but many did not.
NEVER run anti freeze in a race car. Pretty much all tracks and organizations forbid it. Too slippery in a mishap and too hard to cleanup.

 

I run a blown alc sbc dragster and I run water thru the heads only. Because they are aluminum , heat will destroy the area between the center exhaust ports and cause them to colaspe and then you get cross-fire. I use a boat style waterpump as my fuel pump extention and pull water from a tank and pump into the heads just below the center exhaust port and then pull it out the top back into the tank. Water temp lets me know how its running- lean=hot and fat=cool.

 

I help on a BB/FC . BBC blown, alcohol. No water, no problem. Engine block and head temp after a run is about 160 in normal weather. And increases with outside air temp. Hotest this year was 190 at a track where the air temp was over 100.

Block is empty, not filled and the heads are billet, no passages.

We warm up in the pits for about 3 minutes to get over 100*. We do this generally 2 hours before the race. We do 1/2 track burnouts. We cool down after the run with fans, one on the trans and one on the engine. We get down to about 120 for the second run.
We pull the puke lines off the valve covers at the end of the track to vent the engine.

Flush the fuel system with Marvel oil the day after racing.

Change oil every weekend after racing, Maybe next year we're gonna try running 2 weeks on the oil, see how the pressure and contamination looks.

We run safe. Not too fat to wash the cylinders and not to lean to hurt. Took awhile to get it right, and balanced, making small changes.
We tune with timing to get the right ET for the round.

Our 7.3 sec runs normally see the engine run for 3 1/2 to 4 minutes.

 

we run a sbc on pump gas no water no block fill we just keep our eyes on the engine by feeling the front and back of the heads with our hands if it burns its to hot! BUT we only do two meets a year and we make maybe four runs a day with cooling down time aplenty we have been running this engine 350 in a t altered for atleast 10 years no problem sometimes we run nitros sometimes not 11s without the gas 9.6s with NEVER damaged it.

 

Not really true to all Top Fuel engines. I am crew chief on a nostalgia funny car, we run 85% + nitro and never pull the heads at an event unless we have a problem, which is very rare. Nitro as Alcohol will accually help cool the engine.

I don't think it would be possible to run gasoline without problems as Gasoline burns hotter, on cold days we will warm the engine before we switch to nitro to build heat quicker, normally we fire the car on alcohol then turn the pump on to run with the nitro.

I helped a guy once who ran a dragter with a small block chevy on alcohol, it ran super comp and quick turnaround between rounds was a must. He had threaded pet cocks into the block drains and would run water , between rounds we would drain the water and refill (he had some fill tubes plumbed to where the old water pump was once located) with cool water, sometimes a couple of times between rounds. It worked out really well.

If you run alcohol you shouldn't have problems as long as the tune up isn't too lean.

 

Help with a friend's sand drag truck. Shorter track, so it doesn't build as much heat.
SBM, alky (carb), dry engine, no filler.
Used to run a hilborn 354 on alky. Same deal; open block, no filler at the 1/4 mile drags. Quick laps would build heat. usually not a problem until later rounds.
Gas would be an issue dry, lots of guys could do the job with a small tank and the block full of water and cool 'er down (flush out hot water, fill with cool) between rounds. Make sure you don't shock the temps though....

If you decide to go alky, service the system and make sure it's real big.

 

I am by no means an expert and I am still learning about all of this stuff. I have a Fiat Topolino that is a 96" wheelbase altered. It is as raced in 1973. The engine is a 301 Chevy with Hilborn injection on gas. 7A nozzles. We run the block full of water and drain it between rounds, or circulate water through it to cool it in the pits. Back in the late 60's, they ran it dry or wet depending on the day. If it is 95 degrees out it gets hot fast. You can see the aluminum plates where the water pump belongs. We hook up a garden hose and circulate though them. I could add a small cooler and a fan, but then it would be changing the car way too much. This one is all about the way it was.

 

I've been watching your progress with your Topolino - what a great car! Thanks so much for your detailed input, I'll have to take everyones advice in and figure out how we're going to do it.

One thing is clear - we'll have to go alky, which is fine with me. I'll just have to save those pennies...

 

Tarlo,
after you get over the intial expense of an alky carb or injectors the methanol deal is much cheaper than running that high zoot race gas and despite a comment or two here is a lot less sensitive to tuning variables (lots more volume so being a little bit off on the jetting has less effect).
If you run injectors try to mount the pump low and the tank high so that the pump will self prime and after initial start up you probably won't have to use a squirt can to get it started (except on cold days when a shot of gas helps get the fire started).

Roo

 

Tarlo,

Going carbed or injected?

 

To start with it'll be carbed. After all of this great information I need to evaluate a plan of attack.

I'd still like to run the small block 302, I've had it for years and the guy I bought it off spent a small fortune on porting the heads. The SBF is a bit of a challenge getting speed parts for, but I think I'll persevere.

It isn't a case of dream up an engine combo and put it in, I have to build on what I have.

The cheapest option I guess is to simply swap the carby for something a little bigger in CFM that runs alky.

Some people over here have suggested I go to a 2x4 tunnel ram on alky, which may be the cheapest option for more power, but I have heard that tunnel rams have poor low down torque, especially as we plan on running torque sucking zoomies... which is a whole other story and another stupid question thread!

 

No stupid questions. We both learned things we needed to know from this thread.

That small block Ford will make parts selection a little more difficult.
I'd go for a Carb set up for alcohol with a polished aluminum "shark fin" scoop or a fiberglass "surfer " scoop. Both are cool and period correct.

I've got a hilborn injection set up for gas, but after this I'm pretty confident I'll run alcohol. I've got all the parts needed.

I also want to run zoomies. Nothing looks cooler!

 

I have a Hilborn style scoop, so the tunnel ram setup would go nicely with it.

It's funny you mention the shark fin scoop, I originally pictured the car with an Ohio George style fin scoop. Below are the before and after mock ups. By the way, I'm still to design the final signwriting, I need more planning and research and sort my mind out from the hundreds of images I've collected.

 

I love both mock-ups above - BAD ASS!!

Things to consider:

Hilborn scoop looks good on an injected engine - Not as good on a carbed one. With the low hood of the Topo, the carbs, linkage, fuel lines, etc. would be well above the body and might not look so great. I had bought a tunnel ram for my car but decided not to use it for this reason. Also, alcohol carbs are kind of expensive (2 = big $$). The tunnel ram will also kill off some low-end torque which you were concerned about when you mentioned the zoomies.

The shark fin scoop can be used with a single carb. This will save you some $$ and make the car easier to tune. Most racers will tell you that a well tuned single carb car will out run a tunnel ram car any day of the week. It would be ideal if you could find an intake that was low enough to keep the carb under the body so that just the scoop protruded through (like in your pic above).

I'm sorry if I took this thread off on a tangent, but I'm excited about your project and just wanted to share a few thoughts, opinions, ramblings...

 

Thanks for your ramblings!

Perhaps I'll stick with the Edelbrock intake I have, get a single, larger alky carb and make a shark fin scoop.

I can always save the Hilborn until I build a really serious engine.

I'll do some research on what alky carby to buy. I currently have a 600cfm carb for the 302, and I'm sure that it can go quite a bit bigger. I have no idea of what carb to run for racing purposes, and whether it needs to be matched in some way to the zoomies because of the lack of back pressure etc.