Inliners International Forums General Discussion Hi Performance 292 crank

building a 292 for dirt circle track. offy intake,holley 4br.sissill head,12-1 forged pistons,stock rods,they will be recond.also will be cryoed.cam done by lazer cams.would like to turn 6000 to 7000 rpm? will the stock crank hold this kind of pressure? what mods does the crank need? thanks,thor

hello...you sent me email and I havent heard back from you..every thing ok?...Good question-hope you get many responses on this question.... their are 4 different cranks available for the 292- the worst 1 is the forged steel crank only found in 1963-1st yr GM used this crank-they found out VERY quickly how bad this "brittle" crank was for an Inline 6 with a long stroke and a long crank...next they tried ths 6 counter weight cast iron- this was a little better but still not balanced right...next they came up with which some say is the best HP 292 crank- the 12 CW cast iron- see cast iron is fairly soft and actually absorbs more harmonics than steel....this crank has big counter weights compared to the next crank choice-the mexican crank-this mexican is made from Nodular iron (more nickel content for strength)...this nodular crank is the lightest but AGAIN had a brittle factor due to use of Noudular iron....here is some info I have gathered about these cranks-I have heard from many, no matter what crank you use , the 292 harmonics are the worse between 6000-7000 rpm-ESPECIALLY if you use steel rods....all this brings up what balancer are you going to use?-more and more are finding the lighter the balancer on a 292 the better for HP- it works like this-since the crank is sooooo long and has a long stroke, by adding a heavy balancer to the front of the front actually creates MORE harmonic problems-think of it like this- the flywheel or flexplate end is starting to run 1st and if you add weight to the front of the crank , the front of the crank has to "catch up" with the back end-by adding more weight you are creating even more Crank stress and and crank twisting-be very careful here...i do not use a balancer on my 7000+ rpm 292-i have 7.3" large forging rods and I use the heavy cast crank-by having a long rod and Very light piston , you also cut out harmonic problems....mmm sooo, i hope this helps...

what are flow numbers of head you have? are you matching flow #'s to lift of cam?....
Lee

What are the 7.3" forged rods off? If they are readily available, I need the big and small bearing ID's.

Thanks,

Hi THOUR- Myself and a couple of more guys are running 292's in pulling tractors. We turn 6000 rpm's with on problems. There has been no problems with crank or rods. Two of them are stock bottom ends with no mods. and one is the Mex. crank and engine with no mods. except ARP rod bolts and been balanced. Know of one engine that turns 7000 regularly and has had no problems out of the bottom end. The only mishap I have heard of is a guy that had alum. rods. a rod broke and caused major damage. We also run heavy custom built flywheels. We check bearings at least once a year- have had no excessive bearing wear on the mains. The only problem we have had is slipping the outer ring on the balancers. One guy has taken everything off a stock balancer(he does not run the alt. or water pump off the pully). I run a v-8 balancer(8 in.)off a 350. The pulley runs off the hub not the balancer. We haven't had any trouble since back in May. The stock bottom ends of these engines are tough.

Ed, unfortunately these rods are no longer available-my shortblock builder use to race 292's and had a limited supply left that I bought-at 1 time he bought approx 50 sets of these-the name is Brooks Rods(Calif)-i also have a set of 7.0" rods which i have considered selling but not at this time...
....thanks for sharing your info Hud....I wanted to share the info I had gathered about the 6000-7000 rpm range ...the 1st person who shared this info that the harmonics were worse between 6000-7000 rpm was Mike Kirby... about 3-4 years ago after the Power Manual cam out, i talked to him about building a cheap budget drag engine- he just warned me that either build it for under 6000 and or over 7000 rpm-seems what you stated about balancer problems might also lean in this direction too....again it seems there are many ways to build these engines-....I have been confering with many people from the Index in the Power Manual -seems 2 most common elements come up for all out Performance 292's- be careful with what Rpms you turn for longevity and be careful what crank you use .....I have been very surprised to find out that back in the days Of the 292 drag class, many drag racers tried many cranks-even high $$$$steel billet cranks, but the stock none steel cranks worked the best...and from these "old timers" said also holds with what the the Power Manual states- Long Large forging aluminum rods hold up very well and help keep cylinder wall piston pressure down and with this longer rod ratio you can rev higher....its great we can share all this...For those interested, Rob Harrison -the under 8 sec All Aluminum 292 in Canada- uses the Mexican Nodular crank -he has had crank and balancer problems but of recent has stated he thinks he has found a solution......My 292 short block builder, who ran consistent 10.30's in the "day"(i have seen his times in print), tried all the 292 cranks-he is another 1 who tried the steel billet crank/ but it failed also-he found out the cast heavy crank held up the longest in 8000 rpm+ 292's...I dont know all the answers, i just figured those interested might like to know what i have found out-its pretty amazing stuff....Also, of what i believe is of major note, is how knowledgeable Glenn Self is on these Inline 6's...seems he is only brielfy mentioned in the Power Manual....Hope to read more responses here concerning this....

Lee

[QUOTE]Originally posted by LeeLites:
[QB] Ed, unfortunately these rods are no longer available-my shortblock builder use to race 292's and had a limited supply left that I bought-at 1 time he bought approx 50 sets of these-the name is Brooks Rods(Calif)-i also have a set of 7.0" rods which i have considered selling but not at this time...

Thanks Lee. I have 7" rods in my GMC 302 and wanted some longer ones.

thanks for the info guys,its good to know that the lower end is [all most] bullit prof.what about oil pumps? do you use a stock pump,or is there a h. v. pump i should use? dont stop now, keep the info coming.thanks again,THOR

Wasn't carillo making a longer rod for the gmc 302?

Perhaps, however, when I called them up, they said $300. per, which defeats the whole purpose.

Thanks,

I would recommend going with a good stock equivalent oil pump. High volume pumps, especially at the RPM you are going to run can cause the distributor gear and or camshaft gear to eat themselves. Also, it is not unheard of for the tang to get broken off the pump if the gears do no go away.

THOR-When we ran the dirt track with a 292 using componets like yours. The area we had to keep on top of was timing. The harmonics would destroy a mechincal advance. If you can run a HEI or crank trigger. After 10 years of trying to make a regular distributor work we tossed it for a crank trigger. I should have done that 9 1/2 years ago. The oil pump was a high pressure. I dont think they make a high volume pump. The three years we ran this motor we had no failures of any kind. I fact that same motor ended up in my drag truck for the last 4 years.

The need to keep pace with the bent 8s has us pulling it for new and improved piece. For the aluminum rod guy's I bought some GRP billet 7.250 rods. They are awsome compared to the older Super Rod forged pieces.

Lee- If you have that crank driven water pump on there it is still a "fluid damper"

well, well,well, wonder when you would say something Mighty-and again you started this communication between the 2 of us as you left it-LOL...lets say this-i do NOT use a Damper!!!! ...mmmmmmm wonder what I have, huh?-lets say this-without weight of a damper /balancer i guess i dont have the same 292 crank twist that occurs with these cranks and use of a balancer-mmm-ask those that know about this trick-if you know any.... You want my crank mounted water pump?-I have no need for it now-LOL....

Lee

ps- High Volume oil Pumps are available-I have an Hamburger oil pan and HV pump-neither are on the engine I have now though- I use restrictors in my roller lifters to keep oil in pan and crank....

Lee- A six like small block does not need a damper to run because of netrual balance. I wont loose no sleep over it or burn up the phone line either. The Harrison's and Self are running dampers for a reason. My truck is street legal so I still have a altanator and crank trigger on it. A eletric water pump is the only way to go. There are plenty of things that rob horsepower besides crank deflection.

The water pump on the crank was not a smart ass remark it just most poeple wouldnt think of it being a damper. It you want it to be a smart ass answer well I guess it is.

Now on the oil pump thing I would have to check. I think a lot of companies claim high volume through higher pressures infact the gears are the same. I dont know it been a long time sence I messed with that sence I never have oiling problems.

hello Mighty, thanks for comment- I-took your comment about the water pump damper as a smart-XXX comment and responded to you in same way -I am sorry and wrong for doing that now that you have explained what you meant- I would like to become friends and share this together...you have been racing longer than me and I am sure i could use your advice....
However,I will add this-I have found out SOOO much about these engines from the "old timers"-....and well i have been surprised as much as anyone about what they say-all i know is they tell me what works and what what works BEST(there is a difference)-I only have a limited budget so i will listen to them and take their advice...

Lee

LEE,is it a hamburger oil pump? MIGHTY6,what about a msd? i have to run a balancer for the water pump,what do you think about having the motor balanced with the small 283 or 327 balancer? do i need to cross drill the crank or will it be fine w/o any mods.this is our first in line build up,thanks for the help. THOR

Lee- Allright well see if we can play like good kids for a while.

Thor-If the rule let you run a after market damper. We had no luck with a fluid damper. We ran fisher dampers. One thing you have to watch out for is when you wash the motor off go ahead and start it up to get the water out of the clutches of the damper. If you dont it will rust up and cause a bad vibration. I have never ran a TCI Rattler damper but a bunch of freinds run them on bent 8s.

On the MSD question- If the rules let you after market dist. MSD makes a new billet unit. The second choice is a GM HEI unit with a 6AL and blaster coil.

The crank was standard with all the sharp flashing removed and balanced. If you want to get a cross drilled crank that would be O.K. but I never used one.

Check with Raymond at AMS Racing Crankshafts in Bossier City, Lousiana about inline four and six cylinder crankshafts. Website is http://www.amsracing.net or telephone number is 318-222-1915.

hello...thanks for adding info Gerry...how have you been? Havent communicated with u in a long time.....Yes- Raymond at Bossier City-is a great person and engine builder/machinist... I have been communicating with him on Chevy Inline 6's for almost 2 years now....For everyone- he is very busy , but try to talk to him if you have time.....

Thor- yes it is a Hamburger HV oil pump-part #05140..I have the Hamburger oil pan and pickup tube seen on page 40 of the Power Manual. my oil pump is same GM part #(but has been modified and doesnt look like any pictures shown ) as seen on page 39-you can also see how pick up tube comes diff location off pump-i have pick up tube as seen on page 41

Mighty, thanks for comment.... I also have an electric water pump and an alternator ...

Lets hope for the best for people still in Fla now....
Lee

How well will the factory 292 forged crank hold up at lower RPM (5200 RPM max.) for a turbocharged application 12 psi ?

Hi all: Short Newbie question. Has anyone gone to the trouble of converting to a serpentine belt for circle track racing for a HP gain, as opposed to the V belts? We are also running an alt and PS and turning just over 6,000 with a 266. What an interesting thread. I had no idea you could keep a 292 together at the R’s you guys are talking. Thanks for any help!