zipper06

Even smaller than i thought, i was baseing that on the many cranks for sale for the SB-2's on Ebay with 2.300 mains and 1.876 rods.
ops:

434" Lock and Load.



Zip.

DRTRCR22

Well Zip, I never thought about the heat factors on large journal mains...?

I have been hearing a lot about the much smaller "Honda Rod Journals" cranks, but have never seen or heard about smaller mains since extinction of the old 283/327 small journal GM blocks...?

The latest trend [I have been hearing and seeing around my scenes] is to go with big bores (4.125 or bigger) and long strokes (3.75+) for monster torque, and using a much taller gear to knock the RPMs down to a reasonable 7200 or less, also to help prevent blistering the tires off coming out of the corners. That is why Elmore talked my into benching the 3.625 stroke and going with the 3.75 stroke and 4.145 bore to make a 404 instead of the 388.

I agree Zip with ALL your reasons for NOT running oil restrictors in any Dart or World block, that is why I chose to splurge on this engine.
I will keep in mind about the smaller journal sizes and heat factor, as I think you are onto something here...

I think, besides cost savings, that may be one reason most circle track engine builders are now going to the SHP block in 350 mains rather than the Little M block with 400 mains. I was leaning toward the beefy bottom end strength and never considered additional heat factors.

One thought here though... NASCAR engines turn a lot more smooth, steady, consistent RPMs than our engines do, and do not take near the "beating" abuse that we dish out. I don't beleive those small journal engines could take the pounding abuse we give on our battlegrounds...?

I considered building a small journal, very short stroke, high revving screamer (3.00 or 3.25 stroke), but every time I mentioned that I was convinced that is definately the wrong direction for our type of racing abuse.

Also, if you have ever read most dirt track rules, we are very limited in what we are allowed to do. IMCA is VERY strict, with engine claim rules in every class, and top four car (each class) tech inspections every night.
No auminum heads or roller cams, and no quick change rear ends...

Thanks guys, I really appreciate and enjoy the sharing of info. Jim

stickboy331

where i work we build many wisota legal 2bbl dirt 350s. depending on class they are solid or hyd lifter, with stock rockers and single spring. with careful setup this will runup to 7200 or so with good relibality.we did have some issues with top end oiling. rocker arms were turning blue, getting hot. to get to the bottom of this we took a steel valve cover and cut the top off. then welded a sheet metal tube a foot tall to it. on the dyno you could see where the oil was going maybe, then i grabbed the timing lite. by turning the advance dial or switching the pick up to a diffrent cylinder you could see everything. every drop of oil, where it came from, and where it went. we found rockers dont allways squirt straight, and some lifters flow more oil than others. now we could make choices based on fact. by careful parts selection we were able to redirect the oil flow to the rockers. this allowed us to use a lower psi oil pump=more power. springs and rockers are a splash lube deal. oil flow will be determnend by how hot it will get and how long the race is. do not restrict it any more than nessary let some one else try the .050 hole. we dyno with system one screen filters, and use wix race filters. get an oil filter cutter and cut open every filter that comes off your motor! stickboy331

DRTRCR22

Thanks Stick... yeah, I agree with you on that.
I think, if rules allow, that the spraybar valve covers are the best idea, but they are kind of expensive... I think they are legal in IMCA, I will have to check.
I still don't think I want to run a stock low volume pump on my $13k engine though...? I will just add the breathable catch can and keep the 8qt pan full of Joe Gibbs race oil before every race...
Jim

stickboy331

what kind of oil do you use we use brad penn 1030 or 2050

DRTRCR22

Well, to be honest, I am not sure... My engine builder just broke in my new 404 with Joe Gibbs break-in oil last week, and just switched out the light break-in valve springs for the racing springs today.
He is switching me to Joe Gibbs racing oil but I am not sure which grade yet...? I will find out tomorrow when I pick the new bullet up after final run-in.
I had been running Mobil 1 synthetic for years, but he wants JG in this new Dart engine...
Jim

DRTRCR22

Yeah, I have heard a lot of good stuff about Brad Penn, and the following form thread is interesting...
I grew up near Bradford PA, and was very familiar with Kendal oil.
I use to run it in my 70 SS454 Chevelle when I was just a teen... good stuff. Man I wish I had that car back... :cry:

http://www.honda-tech.com/showthread.php?t=1503937

zipper06

Hey Jim,

I did not intentionally knock your engine setup, if i did i appolagise. What i was trying to say was that thru the yrs. of experience is that i prefer to run the smaller main bearing. I have run stock 400 blks for yrs. and still do have a 377" stock blk. I have since the 1980's ran bearing spacers with the 400 blks.with success and the engine above (Dart Lil"M") is my first adventure into a true race block, but i bought it with 350 mains. I will say that with the gearing in my car if i can get it to perform the way it should, it will be turning, close to 8,000 RPM's, but only 5.50 sec. 1/8mi.@3250lbs, if it don't i'll be the laugh of the day. Only time will tell.

Zip.

DRTRCR22

No foul Zip, I didn't take it like that... I really appreciate the discussion and helping info. That's what we are on here for, right?

I just got back from Mike Elmore's shop (Elmore Race Engines @ Carlsbad NM CarQuest) where we did the final run-in with the new valve springs. Man it sounds sweeeeeet!

We discussed the oil topic, and he says he likes Brad Penn green racing oil because it does not foam up in the alky engines.

BUT, he said, that can be VERY decieving as the alky still dilutes the oil down, and not having the foaming indicators can lead one to mistakenly believe it is in much better condition than it really is.

Mike broke in my 404 in with Joe Gibbs Break-In oil, and he wants me to use Joe Gibbs XP4, and change it every week.

With the Wix filter this will come out to about $50 a weekend, but after spending $13K on this bad boy I am not going to argue...

He also highly reccomended putting the 7200 chip in the box, and gearing it for bottom end torque pulling around 7k.

I already put my 6.00 gear back in the floater, which should be just right for local 1/4 mile clay tracks with this much bottom ends now...

Jim

zipper06

Just curious, did the engine builder say if you had to put a zinc additave with the Joe Gibbs oil, since you said you're running flat tappets, or doe it have enough zinc already?

Zip.