Engine Failure

[RICK LAKE]

DAVID GAGNARD David If you pull up the installation procedure you will find that you are to do a stretch bolt procedure min of 3 times before installing the rods for final torque specs. Both ARP 8740 and 2000 bolts need this done.I do agree with Jerry on too many retorqueings on these rod bolts, if they where not changed between the Boss motor and back to the 302 block It's probably why the the motor broke at the rod cap. I took me 2 1/2 hours to do this on my stroker motor. After that the torque reading was in the 70+ lb spec. I went buy the stretch bolt gauge and 2 calls to Barry R. who sold me the kit. ARP also confirmed this in a call to tech. After installation you are to measure the bolt length and like you I mark the rod bolts to watch for any movement or backing out of the holes in the rods. .001" you are to replace the bolts if they stretched this much. I think ARP also tells you this too.
As far a the accusump this is just an insurance thing for the motor to do 2 things, peroil the motor before starting up and keep oil pressure up on high "g" turns. If you where going to race full time, a dry sump. I have a canton road race pan too with scrapers and windage tray. A $350.00 dollar aux oil tank is peanuts for what the motor cost to replace if low or no oil pressure happens when racing. I also have the kill switch for my motor when the oil pressure gets below 20 psi, It didn't work when I broke my first rocker shaft and didn't have the accusump on the motor. You know why, because of the location of the switch being at the housing for the lines. Front of the motor had 25 psi and the back of the motor had nothing. There was no oil in the rocker covers.
If you are going to stay with the 302 stock block I hope you will add girdles to the mains and the valley to strengthen the motor block. I heard that when the Boss block came out there where some issues with machining done on the block. Rear cap and mating surfaces. Dimpeling fixed the mating surfaces. Rear main seal, I didn't hear of a fix for this. May be a Poly seal instaed of rope. Does your crank have grooves in the rear
main area? If not this caused a rear leak.
I will live you something to think about, If you believe everything the OLD RACERS tell you we never would have gotten to where we are today. MUst PRO's drive and don't work on there cars. You, Jerry, and me and others are 1 man garages that have limited funds to do this. I have talked 4 people into adding accusumps in there cars and use them, I just got a thank you letter from a guy that got a broken oil pump drive. The sump saved a $15,000.00 motor. I am a student of building and racing motors, 30+ years. I learn new things everyday about building better, safer, stronger, and more durable motors and cars. Looking forward to see you back on the track and running hard. Rick L.

[DAVID GAGNARD]

Originally Posted by Jerry Clayton

Yep===I'm one of the guys who don't like accu sumps--

I don't think you had any oil problems---- By my count the rod bolts would have been torqued 5 times and I would have replaced them probably on the 2nd build--

It does sound as tho you have a good runner and have been enjoying it--good luck down the road

Yes, I had a good running engine (and hopefully will have another in a month or two) and have had a lot of fun with it...The car is a lot better than the driver,a couple of years ago when I switched from bias to radial tires I was having handling issues and had another driver take my car out for a few laps and his first "hot" lap, he matched my best lap time and the next two laps, knocked a full second off that time each lap!!!!!!!!!

The rod bolts were torqued down 5 times and I never really gave any thought about changing them, I just thought the ARP bolts would last..... I'll be checking with ARP and see what they recommend as for as installation and replacement/service life, that was my fault for not doing that from day one.

It's not that I don't like accu sumps,I would have installed one from day one if I had been advised to do so. After seeing the top vintage race car's set-up, I copied it with my build with the road race pan/oil pump/oil cooler/oil filter and lines.

Try the ARP 2000 Bolt upgrade

will do..........

Rick L.;I'm gonna use the BOSS block since I have it, it's going to a machine shop for a thorough going over.The machine work on it looks superb,my issue was the rear main seal leaking,at one point pouring.. Ford Racing tech was NO help, in fact it was a waste of time to call them. Unless your a NASCAR or NHRA team/builder, don't bother calling them, cause they ain't gonna tell you anything.Hindsight being 20/20, I wish I had bought the Dart block instead of the Ford block.

The shop I spoke with wants me to bring in the block/new crank and bearing and we'll install it in the block and they'll take measurements and check a few other things, machinest says whatever the problem is,he can fix it, he's confident of that. This shop has built 5 or 6 engines on the BOSS block and he told me they had no problems with them....

Looks like I need a rod bolt stretch gauge now, and a call to ARP for their recommeneded procedures,service life. I have an hour meter on my car and I like to try to get 40 hours of running before freshening the motor, I know that's a lot, but the motor is not that wild/radical that it won't do it,it has..... Most of the more radical,high hp motors are freshened every 25 hours, but these guys make at least 150hp (if not more) more than me and turn their motors 8,500rpms when I'm turning mine 6,500 rpms...

Either way, I'm out there doing what I can just having a ball at it.If I could afford it, I'd make a call or two have a professionally built engine built and delivered, but in the meantime, I just keep plugging away.....

All the advise on the rod bolts and stuff is great and now I have some more research to do on that before building the new engine......
Thanks
David

[Jerry Clayton]

David--
Please excuse me for what some may think is hi=jacking your thread but Ithink that this is an appropiate place for these comments especially after Rick's comments-

First off--my qualifications go a wee bit past the 1 man garage/shop
Second--In an engine, any engine, the crankshaft doesn't know what the valve cover says or what kind of rocker arms are on the heads, or even if the block is cast iron or aluminum (the brakes might know that)
Third--do a search for Keeling & Clayton California Charger ( check my gallery for a hint )
In the past year alone my car has been centerfold in Rodders Journal, cover of a some special dragster books, in a HARD cover book, National Dragster, and others that slip my 68 year old mind. Plus over the years we have had many Hot Rod, and other articals including several centerfolds and various tech features.

My cars have held numerous track records, Low ET Top Speed of meet, pole sitter,NHRA National record, Cragar 5 second club, gotten many best appearing, best engineered and also best appearing crew awards.

Revell has made 3 models, 1320inc a diecast, and Johnny Lightening one of them tiny 1/64 models---Revell has even done an reissue on one of the kits .

Besides the fuelers, I have raced Pro-Stock, was one of the first cars to run in the sevens, was the first car that qualified and made all runs in the sevens winning the race over a Pat Musi car, a Reher/Morrison car and the fastest Ford shotgun car at the time.

In mid 1980s I did considerable amount of work on stock block powered Indy Car, and work for several late model dirt stock cars---

In the mid 90s and early 00s, did kkarts with my boys, where karts and engines built by us won many regional and National events including the WKA World Road Racing championship at Daytona, Fla.

If that is enough on qualifications-----I have never had a accusump on any of them as it not only wasn't needed, added considerable weight, but the MOST important factor was because it took oil away from the engine when it needed it MOST, refilling the sump after a long hard braking/corner portion of the track---3 quarts of oil--how long does it take to pump 3 quarts of oil???? how far does your car travel in that time frame?????its like a huge leak in your oil system, taking the oil away from your bearings (and those wonderful roller rockers)---your crank knows this but the before mentioned valve covers don't have any idea--

As for oil pressure needed---we are running a 500 inch 1380hp 10400 rpm engine that most of the time doesn't indicate over 5 psi----however, it has a 5 stage scavage drysump pump that pulls over 20 inches vaccume---it will pull oil thru the engine even if the pump pressure stage goes bad

Enough for now and thanks for the rant

[olddog]

I'm no expert, but I will share some experiance. I have worked with some top engineers and metalergests (sp?) in industry. In particular we were working on gear pumps used to pump molten polymers (plastic) at pressures over 4000 psi. We had shafts that were breaking.

The bolt that you pictured, show signs of a classic failure. The outer ring of the bolt has what they call beach marks. Then the center is where a brittle failure occurred. What causes the beach marks in the outer ring is a slow process. A crack initiates, usually from a scratch or some type of a stress riser such as a sharp machined corner without a radious. The crack slowly grows. As the bolt flexes under load, the two sides of the crack rub on each other, causing the beach marks. As the crack grows, the bolt has less and less cross sectional area, weakening the bolt. At some point the strength of the bolt becomes less than the load put on it and it fails.

If I were to guess - as I am not an expert - the crack has been growing for a long time. Obviously a heavier load on the bolt will make it fail sooner rather than later. Once the crack was started, even if you had never reved it above an idle, the bolt would have eventually failed. It would just have taken longer to continue to crack, until the meat left in the bolt was too small to hold the load at an idle. It usually does take enough load to cause some flexing of the bolt for the crack to start, but not necessarily a higher load than it was designed for.

For a price their are labs that can analize that bolt, and they can tell how many cracks started at exactly what points. I don't think it would be worth the price tag to analize it that far.

Where it broke is just above the joint line of the cap. Perhaps it was nicked when pulling the cap on a bind or something along those lines. The imperfection could have been when the bolt was manufactured.

[olddog]

Originally Posted by Jerry Clayton

the MOST important factor was because it took oil away from the engine when it needed it MOST, refilling the sump after a long hard braking/corner portion of the track---3 quarts of oil--how long does it take to pump 3 quarts of oil???? how far does your car travel in that time frame?????its like a huge leak in your oil system, taking the oil away from your bearings (and those wonderful roller rockers)

Interesting point. So after the accusump saves the engine from a total loss of oil pressure, it causes a low oil flow to the engine as oil is diverted into the accusump to refill it.

Wouldn't a flow restrictor in the direction of filling the accusump slow this to a negligable rate and still allow full flow to the engine? I know there is directional flow restrictors for compressed air and would assume they are made for oil as well.

Certainly a dry sump oil system is better.

[Jerry Clayton]

try working some numbers---90 gallon/hour--3 quarts would take 30 seconds to refill--how far around the track would you go????remember--the oil comes out of the accusump faster than it goes back in because coming out only the engine gets oil but while refilling both the engine and accusump get it----accusumps present more places for failure and increase the risks involved--also adding more weight to the front of the car---WHY???????? do you see any on real race cars??????

[Doug I]

I thought an accusump kept a volume of oil that it fed back into the engine before you started it. Once the pressure gets over ~25psi it "collects" the volume and then isolates it. When you go 'key-on' it feeds that oil back into the engine to boost the pressure before you hit the starter.

[RICK LAKE]

Jerry Clayton I am unsure of your rants with some silly things you have said
You think ALL motors are the same except for the valve covers?? All oiling systems preform the same way for all motors? You think a center oiler motor is just as good as a side oiler ?? You think a Ford motor has a better oiling system than the LS series?? Until the last 5 years, anyone could beat Pat Musi, lets not go there. I have seen enough poorly built motors break from that garage. Top Fuel and Funny cars, look at Rampage rail and funny, worked the bottom end in the 70's, so what, You don't see accusumps on road race cars because they are DRY SUMP in most CLASSES. There are classes where DRY SUMPS are not allowed, I have seen guys running the accusumps on those motors.
You have a ton of QUALIFICATIONS and that's nice. Most people on this forum looking for info on how to extend the life span of there motors and still beat the balls of them. You don't like accusumps, OK but to some people here this is a cheap way that may save a motor if setup right. Do you think that 80% of wear and tear is done on startups? I have run the same bottom end for 8 years, no bearing problems or failures. Cheap eagle rods for an FE motor, started with .0021" ended with .0023" after 8 years of racing. The broken rocker shafts took my oil pressure from 75 psi down to 25 psi. A FE will not live long on this kind of pressure. I am sure with your engineering mind it should not be hard for you to figure out that there was little to no oil pressure to the rockers. If not for the extra 3 quarts, rod or main bearings would have been burnt or welded to the crank or worse. I run a HVHP oil pump with 100 psi spring, It takes my motor 20 seconds to fully recharge the accussump after racing. I vary the air pressure in the bladder side of the tank. I run #12 lines. We build 2 different motors, yours are screamers and high rpm, mine are endurance motors that run for years with minimum maintainance. IMO and just trying to help and suggest a cheaper way of helping a person who at this time doesn't want to add a drysump system to his car. Have a nice evening Rick L.

[DAVID GAGNARD]

For a price their are labs that can analize that bolt, and they can tell how many cracks started at exactly what points. I don't think it would be worth the price tag to analize it that far.

Where it broke is just above the joint line of the cap. Perhaps it was nicked when pulling the cap on a bind or something along those lines. The imperfection could have been when the bolt was manufactured.

Zacctly,and in the end,whichever occured first,(rod bolt backing out or rod bolt breaking), the results are the results, I can't un-do them...Live and learn.....I've certainly learned from this "event" and the advise received here, mainly I screwed up by not changing the rod bolts.... That will not happen again because I didn't change rod bolts.... Seems that's the way I learn a lot of lessons, the hard way.....

I've seen other broken bolts over the years and this one seemed very similar to a lot of bolt failures I've seen..... too many torque cycles,too much stress, whatever, something failed and I've got the results to prove it..... In the final analaysis,I'm pleased with the service the motor gave me and really can't complain about it and I'm not complaining about it, just showing what happened.......

I'll build another one, race another day, and if I can get almost four years of racing/use out of the next one like I got out of this one, I'll be one happy racer!!!!!!!!!!!!!!!

David

[Jerry Clayton]

so Rick---how far do you go on the track in that 20 seconds for the accusump to refill??? or do you pull over after every high g corner for 20 seconds while it fills up????

[vector1]

Originally Posted by Jerry Clayton

so Rick---how far do you go on the track in that 20 seconds for the accusump to refill??? or do you pull over after every high g corner for 20 seconds while it fills up????

it's usually half way down the straight at heartland park at 25 psi, waiting for the pressure to come up so you can hammer it. from a guy who uses one, not myself, i drysump.

sorry, that was my outloud voice, didn't mean to hijack.

[Jerry Clayton]

I'll bet you also kart---road race tracks??

[vector1]

Originally Posted by Jerry Clayton

I'll bet you also kart---road race tracks??

if you're talking to me, i like to say i do but haven't in about a year or so.

[Jerry Clayton]

we haven't since about 2002--youngest son joined air force