I need a new block for my car...
...as the current one was ventilated by a failing connecting rod.
Before everyone jumps up and down, it was just a component failure. The bearings even on the failed con-rod's journal were fine.
But I have a question:
I've been told that the Fiesta (771M) block is a good bit heavier than the 711M block. Is this true?
My car is pretty heavy (975lbs, IIRC) and if I can save weight on a component that now needs to be replaced, I'm all for it.
Have you talked to Jay Ivey about the weight of the BRAND NEW Ford blocks for FF?
CREW for Jeff 89 Reynard or Flag & Comm.
Well, no.
If I had, I wouldn't be here asking the question, would I?
Since Jay won't be building my engine, I don't think it's really very fair to be picking his brain.
Not certain, but I think you could order the new block through Ivey without him building your engine, and there is some information here about it.
Also, I've found that most of the engine builders are willing to give you information about their products even if you are not a customer (yet).
To your original question, I lack the knowledge to answer it sufficiently.
Fiesta block weight
The Fiesta block weighs within 3-4 lbs of the 711M block.
Ah! I didn't know he was selling them as well. I'll keep that in mind.Originally Posted by ccoffin
Thanks. That's what I would have figured, but somebody I know pretty well and who's been racing FF for a long time was suggesting it was a big deal.
The fiesta crank is shorter (length wise not stroke) isn't it because of the front wheel drive. Food for thought
Graham
I already knew that, but thanks.
Jay is one of the great guys in this sport. He will talk to any body about his engines or any formula car in general. Besides, who ever builds your engine may go to Jay for other parts.
CREW for Jeff 89 Reynard or Flag & Comm.
& we should not forget one of the originals Teddy Wenz.
root cause........................?
Ford 2737E connecting rods with compliant pistons & pins operated below 7000rpm are bordering on indestructible in a Kent. unless you were attempting to use Ford rod bolts, it's my sense you haven't identified the root cause of the failure. were the rods polished or "polished" in an attempt to loose some weight? and if so, were they shot peened and checked for straightness afterward? what brand rod bolts were used and how were they torqued (ie: torque wrench or stretch gauge)? are pictures and/or close-up pictures of the presumed failure sight post-able?
Art
artesmith@earthlink.net
Yup.
Nope.
I'll ask for a picture.and if so, were they shot peened and checked for straightness afterward? what brand rod bolts were used and how were they torqued (ie: torque wrench or stretch gauge)? are pictures and/or close-up pictures of the presumed failure sight post-able?
The rod bolts were ARP and I believed they were "torqued" using a stretch gauge.
I've only had one conversation with Terry about the engine since he got it, but what I understand is that he thinks the failure started at a sharp corner where the connecting rod is machined flat to take the head of the bolt.
There was at least one mechanical over-rev of the engine that weekend where I might have gone as high as 8000-8500 RPM, so it may be that I am the author of my own misfortune.
Gzzzrk
That's EXACTLY the sound!
I have a core fiesta block and crank, the block does not have all of the machined bosses for side mounting to the chassis.
“Racing makes heroin addiction look like a vague wish for something salty.” -Peter Egan
Good to know. Thanks, Dan.
At the moment, I'm just mulling over whether I should just source another used block (Fiesta or 711) vs biting the bullet and buying a new M-6010-16K.
I'd heard that weight might have been a larger factor than I'm now reading, but I'm still leaning to getting the new casting.
"...as the current one was ventilated by a failing connecting rod."
"There was at least one mechanical over-rev of the engine that weekend where I might have gone as high as 8000-8500 RPM, so it may be that I am the author of my own misfortune."
there is already far too much misinformation in the community. I for one think it would have been better for the "author" of the post to have acknowledged initially possible/potential/probable "authorship" of the unfortunate explosive storyline.
a Dremel tool and small tapered green (?) stone can be used to radius the root of the inside corner. no guarantee a radius'd 2737E rod will live over revved to 8500rpm, but your chances would be much better....................
Art
artesmith@earthlink.net
"
Quote"
a Dremel tool and small tapered green (?) stone can be used to radius the root of the inside corner. no guarantee a radius'd 2737E rod will live over revved to 8500rpm, but your chances would be much better....................
Is that not what any reputable formula ford engine builder would have done?
I'm sorry I didn't live up to your apparently high standards for transparency...
...but I did only start the thread to ask a question about how much different blocks might weigh.
Are you going to gamble with another motor?I would send it to someone who specializes in the kent. Just sayin!
Are you going to gamble with another motor?
That suggestion had been made to him a while ago. But he runs his own program.
pull the pin......
Yup.
I run my own program.
I investigate, I ask questions (I get a few smarmy answers here and there)...
...and then I make my OWN decision.
One of those decisions one of these days will be what data system I use, and one part of that decision is from whom I will choose to purchase it...
...and it won't be from you.
And that decision and the reasons for it, I will share with anyone who ever asks.
I'd do that if I felt the fault lay in the hands of the builder, but I just don't think that.Are you going to gamble with another motor?
You're entitled to your opinion, but this is not just some hobbyist you know.
Well, lets face it, neither the Kent nor the Pinto are generally designed to turn over 8,000 (unless you have a full blown Esslinger package....There was at least one mechanical over-rev of the engine that weekend where I might have gone as high as 8000-8500 RPM,....
I was walking through the paddock one day and noticed a friend just finishing the replacement of a broken cam follower. Stopped and asked what happened and he said he had over rev'd it beyond 8,000 RPM. I just looked at the engine for a moment, then walked away. WHO WAS I to say geezs Steve you should have Ivey look at that BEFORE you run it again.... but I didn't. Next session out he made 3/4 of a lap before a rod came through the block.
CREW for Jeff 89 Reynard or Flag & Comm.
Yes.. ...well.
I didn't start this thread to highlight my own boneheadedness...
...just to ask a question about the difference between blocks.
Ivey also sells a REV LIMITING rotor that can 'save' engines exposed to such clumsy feet
CREW for Jeff 89 Reynard or Flag & Comm.
Well..... I over reved my small block chevy drag racing a few decades ago. Thougt I had dodged a bullet driving home that night until I ventilated the block with a broken rod doing 15 mph making a right turn at a stop light
"An analog man living in a digital world"
Blocks
I have a number of blocks but each would need to be sleeved, if interested let me know and I'll send you the numbers off the blocks, pics, etc.. I would be looking for $200 per block plus shipping, I'll crate it for free. Also if you need any other parts from the block aeration let me know, I've got plenty of rods, pistons and a few cranks.
It won't save you from shifting from 3rd into 2nd instead of 4th...Ivey also sells a REV LIMITING rotor that can 'save' engines exposed to such clumsy feet
...but thanks.
Thanks, Joe. I'm going to consider my options and talk to my engine guy before deciding what block to go with. Maineville is in Ohio, right?
I said I'd ask Terry for a picture, so here they are:
As he said, the fracture seems to have started at the corner where the rod was machined to take the bolt head, and also as he said, you can see the cross-hatching on the bearing surface so the bearing wasn't spun.
I also did the calculations, and my accidental 3rd to 2nd shift probably resulted in a maximum RPM of about 8000 assuming I waited a little beyond my 6600rpm shift point and calculating from the ratios I was using. If I shifted on that occasion at exactly 6600, then the RPM in 2nd would have been about 7800.
Rev Limiter
Yuppers. Though my error is more likely to be 2nd to 1st instead of 3rd. I've heard Ivey quoted as saying the rods handle compressive loads a lot better than tension - the main cause of engine breaking is that sort of sudden engine braking.It won't save you from shifting from 3rd into 2nd instead of 4th...
...but thanks.
Caldwell D9B - Sold
Crossle' 30/32/45 Mongrel - Sold
RF94 Monoshock - here goes nothin'
Terry said exactly the same thing.
I guess the real lessons are at least two:
1. Remember than any missed shift of that level means your racing is over for at least the time it takes to inspect the engine thoroughly.
2....
DON'T SHIFT INTO THE WRONG GEAR
a second opinion
while it's clearly his decision AND wallet, it's disappointing the "author" seems hell bent on again ignoring the experienced advise & counsel sought in the original e-mail. paying someone experienced in the preparation of Kent's for competition is money well spent.
keeping in mind the limited second hand information posted and the pictures (failure diagnosis pictures are never pretty), I come to very different conclusions on root cause of the failure. poking at root cause probably won't help in this case but hopefully will help others get the right answer down the road. root cause is very different than assigning "fault"! in the near term dwelling on "who shot John" is all wrong; all effort should be directed at getting John the medical help needed to survive or to preclude a similar fate to John's brother.
while far from a scientific sampling approach, the lack of weekly "ventilation reports" here at Apexspeed provides a compelling backdrop for looking else where. looked at nationally, surely every weekend from April to November one or more Kent's are being "over rev'd" and its gone on for a long time. it is very hard to ignore the statistics from a large sample. with the valve springs used by people experienced in the preparation of Kent's for competition, the valves ususally begin to float around 7200rpm. stiffer springs cost horsepower at the flywheel. compliant Kent's, well prepared or not, are intake limited making maximum horsepower someplace between 6000 and 6500rpm depending on a host of second and third order choices. in my experience (primarily associated with cars in the front half of the grid), the number one, number two, and number three concerns when an "over rev" is reported are the valves. floating valves all too frequently are run into by pistons and BENT. comparison of before and after compression gauge readings will confirm or refute the presence of one or more bent valves. most of the time the valve guide is such that a spare valve can be lapped-in at the track to avoid loosing the weekend.
from a root cause analysis perspective, the lack of any mention of the condition of the valves is troubling. it might mean the valves haven't been checked, it might mean the condition of the valves was thought unwarranted for a post requesting information on blocks, or it could mean that springs stiffer than installed by people experienced in the preparation of Kent's for competition were being used. floating valves tend to throttle the engine providing some minimal "over rev" protection. defining the connecting rod loads at 7000 rpm as 100%, to first order the loads at 7500 rpm are 114.8%; at 8000 rpm 130.6%; and 8500 rpm 147.4%. keeping in mind the limited amount of second hand failure data that accompanied the request for information on blocks, the posted pictures, assuming the "author" is no better or worse than other Formula Ford drivers looked at nationally (or US & Canada), assuming the rods were checked for cracks prior to preparation, and assuming the rods were checked for straightness prior to installation, it's my opinion that the most likely root cause for the engine failure was inadequate preparation for competition OR inadequate preparation for competition coupled with use of less than optimum valve springs for competition. the "over rev" event that percipitated the failure is looked at as no worse than what engines prepared by people experienced in the preparation of Kent's for competition see every weekend. more data has the potential to color the conclusion, but probably not change it.
comparison of the three survivors to rods prepared by people experienced in the preparation of Kent's for competition (purchased or loaned) might be an interesting experiment. the devil is always in the details.............!!
Art
artesmith@earthlink.net
Wow...
So much verbiage. Where to start?
Let's start with this:
This thread was about a simple question. I actually didn't ask for anything other than clarification of something I'd been told.
As for the rest, I really don't care enough to listen to the expounding of someone who proclaims that diagnosing root causes is hard and then proceeds to try it on very limited evidence presented by making lots of unfounded assumptions.
need new block.
Go get a 711M block and rebuild the engine. I have over-reved my FF engine by missing third and getting first. The guy who built my engine (GLC) reckoned he could hear it from the stands.
Engine survived. Did pull head off to check I hadn't bent a valve. I run ARP bolts. I selected the wrong gear due to worn joints in the gear change . I have just discovered recently an indent spring and grub screw missing from my 3rd/4th selector.
He likes to argue and is never wrong.
He quotes and uses the comments & the experience from this list in other places <newsgroups>when it suits his needs.
I tried a few years ago to give him some information but he believes that I am trying to sell him something. That would be the last thing I would want to do.
Many other people on the internet refer to him as the type that lives under a bridge.
so Good luck with it.....
Just another data point: I did the same thing to my older second-hand Ivey several times in one weekend, probably hitting 8100 the last one. Finished the session with no problems. Consensus opinion was that I wouldn't know if I'd stretched a rod until it came out the side of the block, so we sent it back for rebuild. It turned out everything was fine. We're at 40 hours since then and it still feels fine.
Caldwell D9B - Sold
Crossle' 30/32/45 Mongrel - Sold
RF94 Monoshock - here goes nothin'
I wish I could put it off to that. Sadly, I can feel the detents are in place.
Thanks, Tim. Good to know.
I think I may just have gotten a little unlucky. Maybe not, but I'm not going to sweat it too much.
two relevant pages from David Vizard's How To Modify Ford S.O.H.C. Engines. should be a simple task to confirm the inside corner on the three surviving rods have been radiused and polished or not.................... it's my opinion that any of the factory machined corners or machining marks in the corners would constitute a "smoking gun" on root cause and explain why others with engines prepared by people experienced in the preparation of Kent's for competition were "lucky" and you weren't .....................
Art
artesmith@earthlink.net
Last edited by Art Smith; 11.11.14 at 9:45 PM.
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