Looking for parts again...

[Kryogenic]

Hey guys, the brand new engine I just built made 4 laps around the track and threw two rods. I am pretty much having to start over again, and im looking for a forged 4" crank for a 340 and h beam 6.123 rods. Let me know if you know someone selling any. Id appreciate it.

[340king]

Which rods did you have problems with?

In my experience, I have never broken a rod. I have had rods break for several other reasons, but not a single one has ever broken on me. Now I haven't raced a million laps or anything like that, but even talking to my machinist, he was hard pressed to remember a single rod failure not attributed to something else.

The reason I mention this is that you need to find that something else prior to rebuilding the engine. Been there and done that, own the Tee shirt!

[dirttrackracer]

Burt listen to me put that motor from your dart in that mod. Its more than enough for a rookie mod driver.
After that you need to talk to ed owner of the #29 stock car he will steer you to reputable machine shop for your next build. I agree with 340 king first you need to find out why it broke.

[JC]

I'm just curious why most people like that 4" crank. I tried it with my Kimmel Car and broke a steel crank, I said if I did it again I was going to try the 3.79 in the 340 to make a 392 vs a 408 rod ratio was just a little better. Mr. Bill Richardson told me I'd make more power and it was a better combo.

[dirtmopar44]

I agree with the 3.79 stroke deal just a better combo for circle track.

[Kryogenic]

Dan,

I was thinking about using the Darts engine in the Modified, that's a good call. Since they cancelled street stock at Kennedale, I was just going to use the Dart for event nights at other tracks a few times a year, but it makes sense. I plan on starting the process of putting the engine in this weekend. I have to make some new motor mounts and get some different headers but over all doable. I figure while i'm building the original engine back, i can get some seat time in it anyway.

I know Ed, he's a super nice guy. He was helping me with some ballast changes last year in the Dart. I'm not exactly sure if im going to keep the exact same combo the Modified's engine had. ill figure something out soon though.

340king - you are right on for sure. I have a good idea what happened to the engine. The rods were not the initial issue they were secondary. I have narrowed it back to the oil pump starving the engine for oil. The rods that broke were just the first ones to give up without the proper oil pressure. Why the oil starvation is still something im checking out.

I will have the modified back running again on the weekend of the 16th.

[JC]

Anybody try this on the oil pumps.

[dirttrackracer]

You can never go wrong with improving the suction side of the oil pump.

Burt my guess would be that you had the oil pickup to close to the bottom of the pan restricting oil intake. I allways welded a 3/8" nut to the bottom of the pickup to keep it at proper clearance even if the bottom of the pan gets pushed up.

[340king]

You need the pan clearance just right. Too high and you suck air and too low and you suck the pan bottom up to your pickup. Typically the first rods to lose pressure are #2 and #3.

We recently built an engine where we used all the oiling mods that were allowable under our rule format. We broke some rocker arms on the dyno and spit a lifter out. When we pulled the engine down I was happy to see that all the rods were in the same shape and that it wasn't just the two up front that were hurt. I know that sounds odd, but having evenly distributed damage was a sign that we had even oiling. So that is a good thing.

[dirtmopar44]

Any time you can increase the input side of the oil pump I would do it. If you are using the stock pickup tube 3/8 pipe and long tube I always drill the pump to 1/2 npt and use a 3/4 .060 tube in place of the small stock pickup tube. I also fab a new pickup screen that is at least 8sq inches.

[Kryogenic]

Originally Posted by dirttrackracer

Burt listen to me put that motor from your dart in that mod. Its more than enough for a rookie mod driver.
After that you need to talk to ed owner of the #29 stock car he will steer you to reputable machine shop for your next build. I agree with 340 king first you need to find out why it broke.

By the way Dan, Rookie??? I'm insulted! J/K. I have the engine in the Modified and i'm going to try and start it tonight. Hopefully I can keep that engine together for a while, im fresh out of them after this one. How are your new heads working with your car?

340 King, I have a question for you. When you were running your Modified im assuming you ran Alcohol in it? I'm all paranoid about the oil getting milky. I know its normal, but as you could guess I'm gun shy about anything bothering the oiling system. I was told you can run about 4 races from a fresh oil change running Alcohol. Does that sound correct to you?

[moparracer54]

I would run gas.....yes alcohol makes more power, but it also burns faster and it can be a pain in the ass. When it burns faster your loosing rear percentage faster which will screw up your handling. Keep it simple and get the car dialed in and worry about power later.

[dirttrackracer]

[QUOTE=Kryogenic;838677]By the way Dan, Rookie??? I'm insulted! J/K. I have the engine in the Modified and i'm going to try and start it tonight. Hopefully I can keep that engine together for a while, im fresh out of them after this one. How are your new heads working with your car?

Rookie..LOL yes you are. going from a 3000# car with sticky tires and a 2bbl to a 2400# car with hard tires and more motor is quite a jump. once you get the hang of it though you wont want to go back. LOL

I still am waiting on the heads. Been struggling with handling and with the new cam I have engine has a ton of tourque of the corner and can spin tires at will so until I get the handleing down its pointless to have more power.

all these rain outs are killing me looks like another week on the trailer just got 2" rain last night.

[Kryogenic]

Originally Posted by moparracer54

I would run gas.....yes alcohol makes more power, but it also burns faster and it can be a pain in the ass. When it burns faster your loosing rear percentage faster which will screw up your handling. Keep it simple and get the car dialed in and worry about power later.

Normally, I would completely agree with you, and I always appreciate advice. I think either one of the engines I have used over powered the track on Gas or Alcohol. I just had the car set up for Alcohol though, and its easier to leave all the stuff set up that way. I'm only going to run alcohol on the Modified, so when I take the engine out im "borrowing" from my dart and put it back, ill for sure change it back over to gas.

From what I have seen so far, Gas is definitely an easier way to go. Power seems to be higher with alcohol, but I am looking forward to the cooling part of it. So when you go to an unorganized track that takes a year to line everyone up and its 100 degrees outside your car isn't boiling hot *Cough Waco*.

[Kryogenic]

[QUOTE=dirttrackracer;838681]

Originally Posted by Kryogenic

By the way Dan, Rookie??? I'm insulted! J/K. I have the engine in the Modified and i'm going to try and start it tonight. Hopefully I can keep that engine together for a while, im fresh out of them after this one. How are your new heads working with your car?

Rookie..LOL yes you are. going from a 3000# car with sticky tires and a 2bbl to a 2400# car with hard tires and more motor is quite a jump. once you get the hang of it though you wont want to go back. LOL

I still am waiting on the heads. Been struggling with handling and with the new cam I have engine has a ton of tourque of the corner and can spin tires at will so until I get the handleing down its pointless to have more power.

all these rain outs are killing me looks like another week on the trailer just got 2" rain last night.

I figure as long as I don't have to keep replacing engines after 4 laps, I have a feeling ill start loving it. It sure did have a crap load of power. I was (early thinking) about maybe advancing the timing a little to take some bottom end torque out if spinning becomes to much of an issue. You think that would help you with spinning? I have never been able to stand on the throttle so its normal to me to always feather it.

I can't believe you are still waiting on the heads, sheesh! Are they just back ordered or what? What changed on your car outside of power to effect the handling so much? Track conditions or just engine power output?

This rain has completely sucked for this season. I'm bouncing off the walls to race and my wife is bouncing with me. Shes definitely ready to get back out there. I'm not sure if I can take many more of these drama free Weekends.

[dirttrackracer]

I guess I need to clairify a little. I received the heads from EQ in late January they were just bare heads. So I took them to the local EQ head guy and he is getting them set up to be I-stock or Sport mod legal in case I decide I can afford to go that route. Right now Im running the local factory stock with the ashphalt pull offs and they just don't have much grip on dirt. so the car needs a different setup to be competitive. the GM metric guys have been doing it for years and have it figured out for the most part but torsion bars and leaf springs are different.

[modracr41]

[QUOTE=Kryogenic;838683]

Originally Posted by dirttrackracer

I figure as long as I don't have to keep replacing engines after 4 laps, I have a feeling ill start loving it. It sure did have a crap load of power. I was (early thinking) about maybe advancing the timing a little to take some bottom end torque out if spinning becomes to much of an issue. You think that would help you with spinning? I have never been able to stand on the throttle so its normal to me to always feather it.

I can't believe you are still waiting on the heads, sheesh! Are they just back ordered or what? What changed on your car outside of power to effect the handling so much? Track conditions or just engine power output?

This rain has completely sucked for this season. I'm bouncing off the walls to race and my wife is bouncing with me. Shes definitely ready to get back out there. I'm not sure if I can take many more of these drama free Weekends.

Not wanting to state the obvious here, but if you aren't aware, I'd be real careful on advancing timing on alcohol. Mopars don't like a lot of advance (23* is about all I would go.) More than that and you'll start blowing head gaskets and melting stuff. And remember, alcohol doesn't detonate like gas does so no ping. Only MELT! Best of luck.

[340king]

I used to run methanol, but with my schedule I was hit and miss each weekend. That meant a lot of extra work each weekend when I did race to purge out the system. Typically it isn't an issue if you run a couple nights each week. But methanol is hygroscopic, it absorbs water. It also tarnishes metal at a fairly decent rate. So purging the carb is a great idea and putting gas in its place works well, especially on cold start.

Now the real issue with methanol is that it kills rings. You will need to replace them much more frequently, on a normal rotation type of deal. I like the gapless rings for this reason. Methanol loses its knock resistance when you lean it out. So try to always be a little on the fat side.

I ran 36° of total timing in my engine and never had an issue. Typically, the issue turns out to be trying to run too lean when you don't have the proper compression to run methanol. I know it can be run with low compression, but it is a real razor's edge for tuning. A tiny bit too fat and the thing is a pig, a tiny bit too lean and you're melting pistons. If you are under 12:1 in compression ratio I would seriously consider sticking with gas.

Typically methanol makes more torque and that is something you don't need with skinny hard tires. If you work on the cooling, it shouldn't be an issue. Good radiator, good fan, special water pump and good shroud will work, especially if you keep everything clean.

As with every option in racing, there are trade offs. Yes methanol cools better and makes more torque, but with it comes several issues that may make it the wrong choice. Gas is more expensive and burns hotter, but it is much easier to tune on a low compression engine and is much easier on the engine in several ways.

Good luck with whatever path you choose. I plan to stay on gasoline for my projects.

[Kryogenic]

Originally Posted by 340king

I used to run methanol, but with my schedule I was hit and miss each weekend. That meant a lot of extra work each weekend when I did race to purge out the system. Typically it isn't an issue if you run a couple nights each week. But methanol is hygroscopic, it absorbs water. It also tarnishes metal at a fairly decent rate. So purging the carb is a great idea and putting gas in its place works well, especially on cold start.

Now the real issue with methanol is that it kills rings. You will need to replace them much more frequently, on a normal rotation type of deal. I like the gapless rings for this reason. Methanol loses its knock resistance when you lean it out. So try to always be a little on the fat side.

I ran 36° of total timing in my engine and never had an issue. Typically, the issue turns out to be trying to run too lean when you don't have the proper compression to run methanol. I know it can be run with low compression, but it is a real razor's edge for tuning. A tiny bit too fat and the thing is a pig, a tiny bit too lean and you're melting pistons. If you are under 12:1 in compression ratio I would seriously consider sticking with gas.

Typically methanol makes more torque and that is something you don't need with skinny hard tires. If you work on the cooling, it shouldn't be an issue. Good radiator, good fan, special water pump and good shroud will work, especially if you keep everything clean.

As with every option in racing, there are trade offs. Yes methanol cools better and makes more torque, but with it comes several issues that may make it the wrong choice. Gas is more expensive and burns hotter, but it is much easier to tune on a low compression engine and is much easier on the engine in several ways.

Good luck with whatever path you choose. I plan to stay on gasoline for my projects.

As always thanks for all the good information. I think i'm going to run this second engine of mine on gas. I have fired it up a few times on Alcohol and the carb I had on the other engine is to big. So at this point, im thinking at least while I have this lower compression engine in here, ill switch back to gas. I definitely don't want to invest into another smaller alcohol carb. The cost of gas stinks, but longevity has a much higher priority with me.

[dirttrackracer]

You should use less than 5 gal of gas a night with that motor I really don't see were alcohol is any cheaper to run.