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Discussion Starter #1
:angryfi: Well, just after I get my son's 69 engine relaced, I go a blow mine up. Just got it pulled today. Here's what happened.

I'm driving along on the freeway, running around 3200 RPM (I have 4.11 rears) Didn't hear a loud bang ( but With the 3' exhaust and Flowmasters I can't hear much anyway), but it the engine dies and up goes a big cloud of smoke. fast forward to today. pull the engine and drop the oil pan. #2 piston is completely vanished, #2 exhaust valve head missing also, #2 rod doesn't look bad and was still connected to the crank (I won't reuse it though), #2 Spark plug was beat up #6 rod has a busted bolt and the rod end cap is bent away from the crank. Oil pan has a million small parts in it but nothing really recognizeable.

Does any one have an idea what may have went wrong? I was wondering if the nut from the #6 rod could have caused the #2 piston to go.... or may the damage to the #6 Rod was caused the #2 piston going. The wrist pin is still in the #2 rod but the piston is completely gone, just little pieces in the pan. Any ideas?

No I must say this..."There had been NO hints that anything was going wrong before it blew"

The pistons are Keith Black Hypereutectic pistons.

I'm thinking now when I rebuild I may just go with a 347 Stroker and put an AOD behind it.:confused:
 

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Just know this: hyperutectic means you just doubled the price of your cast pistons. If you had forged pistons there would be much less damage because the piston would be in one piece still.

Sounds like a rod bolt failure. ARP rod bolts should be a mandatory item in any rebuild too.
 

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69Kat, without seeing the mess it makes it hard to guess what happened to it, but the head of the exhust valve missing gives me some ideas. From your description I'm going to guess that the valve on # 2 cyl broke off and busted everything up in #2 cyl bore. To explain the broken rod bolt on # 6 I figure that a piece of trash from the #2 broken piston got hung up between the # 6 piston skirt and the crank or between the #6 rod and the crank which caused the rod to bind which in turn caused the rod bolt to break. Look at # 6 rod bearing to verify that it wasnt a oil related problem. It will be burnt and scored if it was a lack of oil and I'll bet yours is not like that.


Regardless, make sure that the head is not hurt bad before you plan to reuse it mag the head and the block for cracks that are not visable to the naked eye.

If you drop a valve it wont break a forged piston?? Yeah right.

Dont worry about the Keith Black pistons there plenty good! In fact the Keith Black line of pistons are very good values as alot come in different configuratons that you cant get in the cast piston line as far as valve reliefs, compression heights etc. The little more spent on them more than offsets the extra machine work required with other pistons in alot of applications.


Royce is right about a good set of rod bolts being good cheap insurance on any rebuild but the truth is they will break also under the right circumstances.

If you look close enough the truth will be found in most cases. mm
 

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Back when I was building more engines some 20-odd years ago, (and parts were available), I always used original NOS Ford Boss 351 rod bolts. They were less expensive than the aftermarket bolts (I think Moroso was the only outside source back then) and they were still 180,000 psi tensile strength bolts. Also back then we could still get Boss 351 valvesprings for $24/set. I serioulsy doubt that Ford still has any of those parts available these days though...

I've also heard that Clevelands were notorious for core shift during casting, and that many blocks could not be bored safely oversize at all. Have your block sonic tested for thickness before paying the bucks for boring.

I sincerely wish that the parts aftermarket wouldn't start the overbores at .030. Most blocks would be just fine with an overbore of half that ammount. Why needlessly go all the way to .030 over when you don't have to? Heck, some of the larger commercial rebuilders go all the way to .040 overbore for the first overbore. What a waste of a block!
 

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Sorry, to hear about the bad luck.:(
Seems to be going around lately.
 

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Actually Mark I had a valve bent over backward imbedded in the head with the forged piston nicked in the top but was able to blend out the nick and use it as is.

I had a brand new Ford overhauled replacement 302 shortblock drop a valve and the cast piston parts went throughout the motor destroying everything. The oilpan was not even usable, both heads were junk, hardly anything left to salvage. The extra $100 for forged pistons will pay for itself.

Hyperutectic pistons are in fact slightly stronger cast pistons but they shatter at the first contact in the event of valve float or insufficient valve clearance from installing non - stock cams and not checking the clearance. Just like happens with any other cast piston.
 

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Discussion Starter #7
MM, Royce, Cougrrcj I did check the #6 rod bearing, it didin't appear to be burnt or scored, crank shaft looked ok too.

I'm going to take the head to a machine shop have have it checked out before I dod reuse it. It took a pretty good beating. The heads are cast Iron Dart Heads. I hope that it can be reworked. Those heads are dang expensive. The block is toast. It was bored to .060 over, so when the piston went so did the cylinder wall. I haven't checked under the valve cover yet over #2 cylinder to see if the Ext valve dropped or not, after I got the oil pan dropped I was just too disgusted. But will check it out today, as I start complete disassembly to inspect everything and determine what is reuseable.

I looked last night at SpeedOMotive's web site. They have a pretty decent price for a 347 Short Block. Their in West Covina, CA. Do any of you have any info on their Reputation? I have also check out, Coast High Performance, and their stroker Short blocks are supposed to be good too.

I can get a rebuildable core here for $150. But there's "No replacement for Displacement" and I'm thinking that by the time I spend the money on machine work, 347 Crank, etc. I can get a Balanced and Blueprinted, 347 Shorty cheaper. Opinions...Please!!

Cougar Kitty. Thanks for the condolences
 

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Actully Royce, while I dont doubt that what you incountered actully happened I myself have seen plenty of forged pistons come apart on impact with a valve. Seen some come apart without hitting anything. There not compleatly bullet proof.

The hypers are not as strong granted but you cant just come out and imply there only good for increasing cost over cast pistons!

If you want the cold piston slap in your motors go ahead and use the forged pistons. Most situations dont warrant them.

I know first hand how many 13-1 Alky motors are running in claimer modifieds divisions where cost is a major concern and there running hypers night in and night out, lap after lap at 6-7000 rpm and these pistons rarely ever give trouble.

If indeed he dropped a valve its not quite fair to bash the hyper piston for it. Its not there fault.



69Kat, heres hoping the darts are not hurt, but if they are there is one of the best head repair shops in the country in Indanapolis. Place is called Indy Cyl head. If they cant fix it it cant be fixed. mm
 

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Have to agree, Indy cylinder head is famed for casting repair work.

I agree a Hyper is better for some cases. A claimer engine is probably one of the best cases. And they can give good service if nothing ever goes wrong. Problem is that humans do make errors and that is when having forged pistons are worth having. I know they have saved my butt a couple times and turned a miscalculation into just a minor problem instead of a catastrophe.

Those guys building 13 - 1 alky motors have time and equipment investment that lets them run a certain combination and make it work after developement, experimentation and past experience. When I spend $10,000 or more on one of my 427's I take every precaution to protect that investment. It's not a claimer motor and I expect to enjoy it for a long time so I use good parts, the best if possible.

Piston slap is not anything to worry about, it is a noise while a forged piston comes up to operating temperature. It is also less of a problem with current alloy forged pistons, I don't hear anything in two of my cars that have Arias and Wiseco pistons respectively. They are current technology and run tighter piston to bore clearance than some of the older designs so piston slap is not a factor.

I have a spare 427 that was built many years ago and has some thirty year old TRW original equipment pistons. It has some piston slap noise but it's hard to notice above the solid lifters and header noise, not to mention the exhaust. It's all kind of a symphony and I enjoy listening to it warm up.
 

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Royce now heres the difference! These guys with the 13-1 alky motors I'm talking about are guys just like I used to be for a short time when I was running under IMCA rules, just average Joe's putting them together in there own garage. There not paying someone to research and put them together for them.

Keith Black, Sterling etc are the ones who have done the expense and research as far as the pistons are concerned.

We can agree to disagree and thats fine and I do agree with you alot till it comes to the money is no object part of it.

Now I would say if I was doing $10k or more on a 427 then I would expect no less than a set of Arias pistons. The simple fact is that 90% of the people on this board will find that for them a set of Arias is a expense they dont need.

I know how much they cost having used both weisco and J&E's myself over the years but I wouldnt spend the money on them for my weekend cruiser.

My point was that if these hypers will take the abuse that these types of racers dish out to them that they are perfectly suitable for the daily driver or weekend cruiser that may even want to take it to the strip now and then.

Not everyone can afford the "best" all the time, and then they have to settle for the "best" that they can afford. Even you will agree that the hypers are a nice step up from stock cast pistons.

Also like I mentioned earlier the Kieth Blacks are really nice in some of the configurations that they offer at a modest price. Take my 460 for example, they offer a pistion with a raised compression height to help step up the compression right to the 10-1 area without having to do alot of maching to block or heads to achive that compression. So ok they cost more than cast pistons but they save alot in machine work, plus they are a better piston. They also list quite a few stroker pistons.

I just found it peculiar that you would mention the forged piston situation when in fact it could be a blessing if the hyper piston shatters on a dropped valve and just maybe save a expensive head instead. I have seen that happen. mm
 

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Yup, we are going to have to agree to disagree.

Here is what my cast piston incident looked like:

http://www.kkpony.com/IBrokeMyEngine/

This guy spent mega dollars on his motor and something still went very wrong.
 

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Well I cant help but jump in on this one!!! I have built 6 engines of my own by myself in the last 3 years. 1 351w with TRW Forged 11.5:1 domes (No piston noise, drag raced it 2 yrs myself, sold it and still runs strong). 351c 10:1 trw flat tops (daily driver, gets beat on alot, no piston noise still runs good). 302 9:1 cast sealed power (daily driver, reliable runs great). 460 sealed power hypers stock comp, no complaints. 350 chevy 10:1 flattop TRW forged, no noise daily driver/car tower still running great. 408 Pure stock chevy sealed power hypers 13:1 domes, ran all year no problems with them. Actually in the 408 I used dbbl hump heads and when my buddy put was helping me he put the wrong spark plugs in (BB plugs are longer reach!) and they hit everypiston HARD, I removed the heads, smoothed and buffed off the nicks/gouges put it back together and run the hell out of it (7000 rpm) all year without a trouble. So my opinion is anything more than stock go at least hypers, if (cont)
 

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(cont from above) your gonna all out race it and depend on it spend the bucks on Forged poistons. I agree with Royce that with todays technology piston slap is pretty much non existant anymore. I've had good luck with all types but you need the other important parts as well (rod bolts, etc.) and a GOOD machine shop. There is a difference. This shop I was going to use one time didn't think it made a difference which stone (grit) to use when honing the block depending on the rings you are using, they said it didn't matter!!! IT DOES!. Anyhow I feel better that I got to get in on the difference of opinion!!!
Scott
 

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Discussion Starter #14
So. Calf Info

:confused: any of you from So. Calf know anything about SpeedOmotive in West Covina. They have a 302 to 347 Short block for $1900. Doesn't appear to bad from the spec's on their web page and the parts seem to be name brands. I was just wondering if anyone knows their Repuation out there? I am really considering buying one from them. 450+ horses out of a bored and stroke 302 is getting my attention. They list a 302 bored and stroke to a 378 but that has to be really pushing the envelope.

Their web address is: www.speedomotive.com

Thanks all,
Ron

Royce, you used to live in SOCAL, you ever hear of these guys?
 

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Scott, you kinda summed up what I was trying to get across. The hypers ARE worth the little extra spent on a mid range performance motor. And they are superior to a cast piston. I was understanding Royce to more or less saying there not any good and if your not going with forged pistons then you might as well run cast pistons! And I totally disagree with that.


Ron, let me ask you a question. What Dart heads do you have, the seniors or the Jr's? Because for what your talking about spending on the little stroker and if you have the senior heads I would think that you should be able to do a 351w for that.

Hell a 393 stroker crank is only $500 and I seem to recall seeing complete balanced assemblies going in the $1000-1200 range.

That said you sould be able to find a core motor for $100 or less and the machine work on the block and a cam kit shouldnt put you over the $2000 mark total. Otherwise all the extras you would need is basically a intake.

I wouldnt think twice about which way I would go if I already had the heads for the 351 or bigger, but if you have the jr's then there really a little small for any bigger cubes then your already talking. mm
 

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Just got a new Jeg's catalog today. Here are the prices for Speed Pro pistons that fit a .030" oversize 351W:

Hyperutectic: $239.32 set of eight P/N 844-H535CP30
Forged : $263.92 set of eight P/N 844-L2446F30

Keith Black for the same application in Hyper cast are pistons are much cheaper at $207.92 set of eight P/N 648-KB136+030.

Difference in price from the cheapest KB cast to Speed Pro forged = $58.00. Knowing you have good pistons in your engine = PRICELESS! (couldn't resist)

Anybody here think that's not worth it?
 

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Discussion Starter #17
Heads

Mark, Here's what I have and I had thought about the 351, but I do have the 58cc Jr. Heads, (although they have been ported and polished). Other parts include a Weiand Stealth dual plane intake, Carter AFB 750 CFM carb. and a Comp Cams, 280H Magnum Series Cam, it's specs are Gross lift Int/Exh .512 with [email protected] Int 230 Exh 230. and Harland Sharpe Roller Rockers.

If I had the Larger heads I would be looking for a 351 to have bored and stroked. But since I have the smaller heads looks like I will stick with a bored and stroked 302. I have check out Coast High Performance and Ford Racing also. The prices for their short block 347's were $1999 and $2400 (through Summit) respectively.

A 347 Stroker Kit from Summit is $1480. and it has to be professionally balanced. I have seen kits that are in the $1000 range and I can get a rebuildable core here for $150. But here's kinda what I'm thinking. If putting the short block together is going to run me close to the same cost as getting one already built, I would rather get one that's already together and invest my time into something else. If I can save $500 or better building it myself, then I would rather go that way.

Does anyone have recommendations on other places that I can check out.

Thanks,
Ron
 

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Ron, I have to agree with your thinking. I think your on the right track.

Royce with what your talking now I would also agree with you but earlier your were talking Arias or Weisco which are not exactly in the same price range as the generic speed pros. mm
 

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Arias, Ross, JE and Wiseco are the only thing available for a 427. Speed Pro quit making anything below a certain volume after their bankruptcy filing so there is no choice for 427 engines except high end pistons.

On the other hand the 289, 302, 351 W/C, 390, 428CJ, 429 and 460 forged Speed Pro pistons are only a small premium over hypers.
 

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Ok Ron,
It's your car and your cash, but unless your all out drag racing with a tunnel ram the Windsor Jrs. are plenty for a street car. My last Windsor I built had 70 351w 2bbl heads fully ported and polished, crower .570 lift mechanical cam, roller rockers, Victor Jr intake and I was running Mid 11's on &H racemaster street legal tires spinning a little! So your heads are better than what I had and you wont be using as big an intake or cam (probably). GO TO THE 351W DA*NIT!!!! :D :D Think about it even if you didn't storke the 351 and bored it it would still be 10 CID bigger than the 347 and built with the same combination would still be more powerful and WAY more reliable. Before you build a 347 start reasearching them, they have trouble with them because of the awkward angle it puts on the rods... Its an EASY decision if you ask me, if you go 347 I GUARANTEE YOU'LL kick yourself in the A$$ later!!
:D :D
Scott
 
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