454 engine help

[psdperformance]

Okay first time posting here this is my ongoing problem,
Rebuilt 454 chevy .060 over KB pistons 9.5 compression comp cams jet boat cam hydraulic cam new every thing in motor. MSd distributor holly 850 cfm.
Thgis boat was bought last year and we got 2 trips out of it and number 1 piston melted so we tore it down and took the block and heads to the machine shop to do their magic to it. They bored the block and machined everthing. we had a friend put it back together and the cam went flat on breakin. Pulled the motor and put in new cam and new lifters,bearing oilpump etc again. This time our friend installed the compcam gear wrong and the valves hit the pistons so we tore it down again. Back to the macine shop we go this time we had them put in new valves again new bearings etc and they longblocked the motor so now we have a professionally built motor. We put the new motor in the boat put in dist. and set timing to 32 degrees advanced at 4000 rpm. We only run premium fuel and we had the carb professionally rebuilt. We took the boat to elsinore and made 1 lap around the lake everthing looked good so we went to havasu this weekend made it almost to the sandbar and POP! lost power lots of smoke lifted the engine hatch and it's puking oil out of the number 1 exhaust again!!! The machine shop sleaved and bored that same cylinder last time. I think there is something wrong with the block?? I do not know what to think at this time but am looking for advice on why number 1 cylinder would keep going out like this??
Thank Chris :confused: :mad:

[76BARRON]

did you check piston/valve clearence? gaskets leaking(vacuum)? head bolt torque? Take a look at the heads? look for evidence of leak's water or air.
good luck!

[psdperformance]

Hi,
No i did not check for torque spec on the heads i guess i just took for granted that being it was professional built engine i didn't have to ckeck much. Piston to valve clearance should have been done by the machine shop? as they were building the motor? I was thinking could water some how be leaking into the cylinder? if so how and where would it be leaking?
Thanks Chris

[Moneypitt]

Which KB pistons, I smell hypertunic (sp) here...............MP

[tbanzer]

Are you sure your timing marks are correct. I have seen balancers off as much as 15degs. Make sure you make sure where tdc is b4 you go any further.

[psdperformance]

Hi,
the engine builder set up tdc and installed the balancer before i got the motor he said it was dead nuts? i guess i should have check it out before . I will be pulling the motor this weekend and taking the motor back to the engine builder. Detonatiion would be the only cause of the piston being burned up again?

[SmokinLowriderSS]

If you're getting detonation, sounds like a lean cylinder. DId you do a mixture run on it? Doesn't sound like it. What intake you got under the holley? Any vac leak at #1 will make it lean (manifold joint to head). If ya got a water leak at the corner of the manifold. and it leaked inward, you COULD injest water and hydraulic the cylinder. I'd be looking there if the piston is broke but NOT melted. Any water in the oil? How is your cooling and exhaust system set up?

[Nucking futs]

Keith black hypertech pistons are known for blowing the tops off if your ring gap isnt right. Just a thought.

[GofastRacer]

Which KB pistons, I smell hypertunic (sp) here...............MP
It's "Hyperjunk"!.. ;)

[78Eliminator]

Personally, I would take your stuff to one guy, and let him rebuild the entire motor. Ask around and find someone who knows what they are doing. Lots of motor guys here in socal.

[psdperformance]

I am running a strip dominater intake, and am running harden exhaust manifold logs it is a pretty straight forward setup. I do know about the ring gap on the KB pistons but i did not build this motor the engine builder rebuilt it from the ground up this time. The first time the number 1 cylinder went it melted a speed pro forged piston it looked like it melted and disdinigrated? the block got bored and it never had a chance to happen again the next 2 times as other things happened. I took the motor to the engine builder the last time this is why i knoe there is a problem somewhere as he said the number 1 cylinder had etching in it ther probably was only 1-2 hrs on the motor from the last time he bored it and said he needed to sleeve it and bore it back to .060 so i did not have to rebuy a set of pistons. he built it and 1 hour later it blew again? i will pull the motor and take the head off and put up pics of spark plugs and what i find in the motor. :devil:

[SmokinLowriderSS]

Any piston is likely to lose it's top if a ring expands together and suddenly becomes unnaturally "gapless", not just HyperU's. It is my understanding that boat engines need to NOT be at the minimum ring gap measurements specifically because they live in a much higher strain, hotter, more unevenly expanding world than car engines do. They should have several thousandths of additional gap to prevent a ring closure/seisure.

[lilrick]

motor magic 562 925 9261

[psdperformance]

Okay i tore the motor down and found number 1 cylinder has a hole in the top of the piston :confused: What does not make sence is all of the other piston look great it looks as though the motor was running rich alot of black sut in the cumbustion chamber and the exhaust ports on the heads. We are running 10-1 compression we ran 92 octane fuel set advance at 32 degrees
total we are running a holly 850 double pumper carb and the jets ar 82's in each corner? what would cause number 1 cylinder to lean out and blow a hole in the piston? :hammerhea
Thanks chris :crossx:

[team 933]

KB pistons suck use Larry @ motor magic or...........Superior automotive [url]http://www.superiorautomotive.com/index.html

[SmokinLowriderSS]

I'm suspicious of an air leak someplace. Same symptom of detonation, same cylinder, hyper-U parts or not.
Same manifold, same heads, I'd be looking all over to he!! and back for a crack someplace.
An unevenness at the #1 cyl port in either part (head or manifold) may keep the gasket from sealing properly.
Some imperfection in the mating surface somewhere, if the manifold doesn't fit just exactly right, Something is letting #1 get lean IMO.

[Moneypitt]

Are you missing any shop rags??..........MP

[Wicked Performance Boats]

Is the intake manifold a dualplane ? Budlight

[psdperformance]

HI,
I am running a holly strip dominator single plane manifold. I have all of the parts at the engine builders shop rite know and they are checking all of the parts out for me. Is this intake manifold a good one for a jet boat application?
Or should i go with a edelbrock manifold if so which style ?
Thanks Chris

[SmokinLowriderSS]

From what I have seen generally (Oh boy, here comes one of my patented generalizations), the dual planes have been better for the jet boats unless you have the power to spin a lot of R's. Most boats are turning arround 5K and at that level I think you'll get better response and maybe even more power from something like my Edelbrock Performer RPM Air Gap. The RPM has a cutout in the separator plate to behave partly like a single-plenum at high revs. The Air Gap design stays cooler by actually keeping the bottom of the runners physically away from the oil splash in the valley area. It's rated to 6,500RPM.
OK everybody. Time to correct Smokin' :D

[909]

Smokin, not going to correct you. You are correct on the why the air gap runs cooler. I'm not clear on if the block was decked or not, this can cause the manifold to not seat properly if it wasn't straight across all cylinders. The thing that stands out is the fact that there was no leak down done on the new motor after all the problems with #1 in the past. This would be the first thing we'd do before firing the motor after all that. It really seems to me that there is an air leak in that #1 cylinder and it's fairly big if the other 7 are rich and #1 is blowing holes in the pistons. The other item that comes up is the fuel octane. at 10:1 (assuming this is correct but we really don't KNOW that because I doubt anyone has cc'd the heads since machining). I'm betting you're going by the CR on the pistons. These assume a stock cc head. These engins are assumed to be under constant heavy load. so octane recommendations are based on the catual compression ratios and load assumption to be on the safe side. I show the recommended minimum octane to be 98 according to my info collected over time. This would mean a 50/50 mix of 91 and 110 leaded race fuel. If the machine shop did remove anything off the head or if you're running hi-comp head gaskets this number would go up. You may be looking at being on the safe side by jetting for 100% AV or mixing as suggested. I would also inspect each cylinder top dead deck height just to be sure nothing is out of whack (stretched rod etc..) before assembly. Option X would be to toss in a crate motor if you really don't want to go down this road again. At least it has a GM warranty to back it as long as you forgot to mention it's marine use to the shop you buy it from.
Good luck, hope some of this helps. We are local so call if you have any questions. 909-972-1730
We're in elsinore
Thanks,
Jerad

[psdperformance]

Hi,
The block was decked,line honed and bored. The compression ratio with the piston and a stock head was supposed to be 9.5. I know that the compression ratio is higher than that as the heads have been machined before. To answer your question no the engine builder did not cc the heads and when i put a compression gauge to check the compression each cylinder blew about 225-230 psi. He guessed the compression ratio at 10.1 or 10.5 but it was only a quess. When i asked him specifically what type of fuel we will need to run he said i should be okay with 92 octane. I do not tknow much about 454 engines and what type of fuel to run with what compression ratios i though it was a little high for pump gas but this is why i retarded the timing to 32 degrees total avanced i figured this would help and we would be okay with 92 octane. One question i do have is if the motor was not running the correct fuel wouldn't it show detonation in more than one cylinder? The rest of the motor (piston,combustion chamber) looked great and the plugs looked great no signs of detonation this is why i figured we were okay fuel whise. Let me know your opinions.
Thank You, Chris :hammerhea

[1BIGJIM]

cylinder blew about 225-230 psi wow that is high. :supp: I would eliminate the guessing and measure everything and find out exactly what the static compression is. Did you degree in the cam? That could effect your cranking pressure also.

[psdperformance]

Yes the cam was degreed in it is a comp cams grind for a jet boat. Maybe there is nothing wrong with the intake/carb and we were running fuel that did not have enough octane?????????????????? :idea: Who has the exact numbers regarding compression ratio and fuel octane rating? what is the highest amount of compression you can run on pump gas?
Thanks Chris

[Schiada76]

Are you missing any shop rags??..........MP
Hey! Watch it! :D

[SmokinLowriderSS]

From those latest figures (and I have no serious racing experience to draw from) but that ACTUAL comp ratio (whatever it is with a 225PSI compression) does seem too high for 92 octane. If the pistons would be 9.5 in a non-modified 122CC chamber like mine (the head casting #s and a trip to Mortec should get you orriginal designed chamber volumes so you can get close) Then milling the head a time or 2 will raise the actual comp ratio, possibly several 1/10ths at a time. 9.5:1 should actually work with 92 octane but I'm doubtful 10:1 will without aluminum heads (they cool faster than cast iron so avoid detonation untill slightly higher CR is used)
I think 909 is in the right balpark. :cool:
It's just the weirdness of it being #1 cyl all the time that throws me for a curve. Maybe some quirk to the manifold causes the farthest away cylinder to detonate first. Maybe an odd spark plug a heat range too hot got put in there, twice? (I'm grasping at straws here for an explanation of the #1 thing). :(
I'm doing some net digging to see if anything can be extrapolated from 225 to 230 psi pressures. :cool:

[909]

to try and figure out CR from little info is going to be next to impossible to do. Using the stock bore and stroke (4.2x4.0) a high compression head dome size for this configuration (100cc) a zero deck height, flat top pistons, and.020 head gaskets. This is an extreme configuration without using pop-up pistons. This yeilded a 9.9:1 on the calculator.
This setup is all based on assumptions and guesses.
This setup would be recommended to run a minimum of 98 octane. This would be a 50/50 mix of 91 pump and 110LL av.
To run 91 pump, no more than 9:1 CR in a boat.
There is no ACCURATE way to convert a static compression number into a CR. The only way is to really measure it out which BTW should have been done before machining. You deck a block to get a specific deck height with a specific piston set to achieve a specific squish. Head milling is done to achieve a specific cc on the dome. All of these factors are to give you a specific CR at the end of the build that gets passed along to the customer and has a direct effect on the customers orders to run a specific gas choice. Period. If you didn't get any of this info and gave instructions to run 91 pump i'd be really pissed right about now. You can run thicker head gaskets or swap heads to get a bigger dome volume but this should be calculated NOW so that you have options here.
Real quick, the reason a static comp. number will not translate to a CR is due to the cam timing. The exhaust valve can open early or later resulting in different peak static numbers but have the same ratio. The compression ratio is total cylinder volume at BDC with the head and both valves closed, compared to the same cylinder, piston at TDC and both valves closed. how much does that volume compress?
As far as the #1 cylinder deal, I believe this is either caused by a leaky manifold making #1 run a hair leaner, generating more heat and detonation. It may also be just the fact that the heads and block were decked but the manifold was not set up to seal properly. This engine is like a 40 year old grenade without the pin in it as it is. You need an engine builder to look at it and report back everything i've outlined here and my previous post and make a suggestion based on his gathering of this info. If you take it somewhere and they do not have this info on their own, leave immediately and go elsewhere. You have a major problem and it will continue untill it is corrected one way or another.
Here is a great article on how compression ratio, compression, etc. play a role with each other.
http://www.beckracing.com/page07.htm

[racing g-man]

hi, dont know which machine shop you have been dealing with, but if you are having the work done in temecula or murrieta there are only a few machine shops. i should know, i own one of them. if you want to call me & discuss the problem i would be happy to help you out. at the very least everything should be messured & clearenced checked !!!!!!!!!!!!!!! that includes cc'ing the heads & calculating the actual compression ratio. i dont generally pay much money for someone to GUESS at something.
greg landes
millennium motorsports
43084 rancho way #c
temecula ca, 92590
951-699-1889

[Floored]

When they degreed it did they go staight up or give you a 4 deg advance? Many comp cams are ground 4 deg advanced and if you add 4 more you get high cranking numbers like that. When I assemble an engine I always set the intake on without the gaskets and check the fitment before going any farther. Look at cap and wires to be sure #1 isn't crossfiring with #2 which would kill #1.

[SmokinLowriderSS]

My Isky Cam is set straight up as I was told by DuaneHTP (got it from him) it is ground 4* advanced.
Said he used to have it made straight and tell folks to degree it 4*, and they'd get it wrong a lot, retard it 4*, then they'd be unhappy. He just has them made 4* adv now and says "Put it in straight up". :cool:

[83Dana454]

I had a similar problem to yours a few months ago. Purchased my boat alittle over a year ago. Previous owner had the engine rebuilt, .030 over 454, cast iron heads, performer rpm air gap, 850 holley, comp cams marine cam, he stated engine was at 10:1 compression and has always ran 92 in it. Ran the boat as I bought it for a season then over the winter months installed a thermostat kit in it to bring the operating temp up alittle bit. Second time out with the thermostat kit the boat started smoking under accel, had alot of blow by out of the breather and was missing. Started pulling plugs after getting it home and found #3 smashed flat with aluminum colored deposits on it. After the vomiting feeling subsided alittle bit I pulled the head and found the #3 piston had a hole melted in it, all the others looked perfect. The machine shop that I had do the work on the block found that my compression ratio was closer to 10.5:1 then the 10:1 that I originally thought I had and by upping the cooling system temp alittle bit by installing the thermostat kit was just enough to put that one cylinder into detonation. Ended up having to sleeve that cylinder due to a crack cause by the extreme temps during meltdown, upgraded to forged SRP pistons over the cheapo sealed power hypereutectics that were in there, switched over to aluminum heads, and now have a compression ratio of 10.2:1. I'm also no longer running the T-stat. The engine shop said that it was better to run the engine alittle cooler in a boat application with a higher compression ratio using pump gas.

[psdperformance]

Well after looking at everything on this motor and everthing checked out fine
we were very stumped on why it was detonating the was it was. We rechecked the compression ratio it is a little lower than we thought it is 9.65
we rechecked the carb everything looks godd so it must be the ignition system. I checked the part number on the distributor on msd website and come to find out is is supposed to be run with F#@@ing BOX!!!!! We bought this boat used and we never check the part number to double check. And MSD stopped making that distributor!We are going to throw a new mallory marine distributor in and call it a day. Many thanks to you all for helping me with this problem you guys rock!! :rollside:
Later Chris

[SmokinLowriderSS]

I think I'm with Riodog again on THIS one too. :cool:

[psdperformance]

Okay, friday i talked to msd and they said the distributor i have is a ready to run dist. Old style with a bule box attatched to the side. They said the dist. has nothing to do with the motor detonating and blowing a hole in the piston.
Know i am really confused i should be getting the motor back thiss week coming up but am really scared to but it into the boat. I am going to put a points style distributor into the boat but am still scared to fire it back up and runit in the lake. :eek: Question for you guys How would i check to see if one head was milled more than another how would i measure it? I was thinking if one head was cut say .020 or .030 more than the other the intake manifold would not sit square onto the head and actually cause the intake manifold to sit high on one side and lower on the other and have a leak on the inside of the manifold which in turn would suck say oil and crankcase pressure into the cylinder causing detonation??? So i would never be able to detect an intake leak on the outside of the manifold by say squirting wd40 where the manifold and the head comes together? could this be possible?? :eek:

[psdperformance]

I also have another idea. what if i put red dycum on the intake side of the heads and installed the intake manifold onto the motor and removed to see if it is sitting square i should in turn see the red on the intake manifold when i lift it off of the motor? to see if it is sitting square?
Chris

[SmokinLowriderSS]

Just put the intake on gasketless, loosely install the bolts (for alignment purposes, and see how tightly it fits. A good set of Calipers ought to be able to discern anything far enough out-of-whack to cause you leakage.

[psdperformance]

Thanks to all who have posted on this problem. I will be getting the motor back next week sometime. Riodog, thanks for blessing us little people with your all wise and knowing post, owe and thanks for letting me down easy as you stated.. I do not claim to or will ever claim to be a v-8 engine builder as i prefer to leave it to the professionals. But i am new to boats and trying to learn as i go so i can someday hopefully save some $$$. A friend once told me that BOATS stands for (Break Out Another Thousand) and am in agreement with him. Your post only makes you look like a jerk which you probably are so please if you have nothing good to say than just keep it to yourself and stay off of this post. :crossx:
Chris

[TJS]

I have been following this thread from the start. I agree with RIO. You need to read, read, and more read all you can. I read and then learned by doing as well. The books will give you a reference to turn to. I have BBC SBC and SBF books (most of them in the bathroom :wink: ). I am in the process of building a BBC and my block is at the machine shop right now. I will be re-measuring everything and checking the piston to deck as well when I get it back. Goodson tools has some inexpensive tools for doing this. You should get a set cause it sounds like your machinist or you are just guessing at a figure in what you have for CR. Good luck. PS RIO you are not being a Jerk you are just telling it like it is.
T.J.
www.tjsperformance.com

[psdperformance]

Again thanks to everyone and sorry if my posts are all over the place just looking for suggestions which i have plenty of. Riodog muffler bearings you sound just like my dad that's a good one. As far as bieng serious about needing help i never thought or take any of these threads serious this is just a fun way of trying to get some input. So relax take a deep breath and enjoy your day!
Chris :rollside:

[blowngas]

I've been following this with a lot of interest as to why the first piston failed----I may be out in left field, but have you checked the cooling system plumbing??----I realize jets can be plumbed up several different ways, but if you are not getting the cooling you need to all cylinders, then it"s a problem----if you're getting detenation, and it sounds like you are, then you need to to run your motor as cool as you can----(no T-stat)---- instead of worrying about condensation----most jets oil runs too hot anyway-----run two water outlets instead of tieing them together----this way you can see if one side is flowing more than the other----do check everything like Rio says, but also check out your cooling system

[steve d]

psdperformance, dude I really don't mean to be insulting and I am trying to be gentle (something I AM NOT known for), BUT you are so far out of touch with reality it's actually funny to anyone that's even screwed in a sparkplug! TELL US, this entire thread is a joke and you're laughing your as* off at everyone that's been trying to help you.
It's your last post that 'outted' you. BUT, being the helpful person that I am- I'm gonna tell you how to find out if your intake manifold to head surface is not sealing and sucking fumes into the cylinders, and you won't even have to go through all of the trouble of disassembling everything 2 or 3 times.
Now PAY ATTENTION!
Take 2 cans of ETHER ( starting fluid) and spray them completely down the dipstick tube. When you are done then put the dipstick back in and you're ready to start the engine.
NOW start the engine and if everything is sealed up and tight then the engine will just sit there and idle and the ether will be blown out of the breathers and you're good to go.
However if you see a different reaction then you know you have a problem and know right where to look, lol and NO MORE 97 QUESTIONS!
Now git to it and let us know how things turn out!
Rio
HOPEFULLY THERE ARE NO BROKEN RINGS...........BINGO

[steve d]

EERRR, psdperformance, since steve d quoted my sarcastic post about the ether I felt compelled to give this WARNING. DO NOT squirt ether in anything period! That was supposed to be a funny and get a response out of the crew and I didn't think anyone would ever take it seriously. I'd feel really bad iffin you blew the intake manifold through your roof. LOL
Rio
steve d, not 'bingo' -BOOM !
Well Rio I wanted to be a little subtle..........Steve

[SmokinLowriderSS]

Geez rio, I can't believe I myself missed the bit about the "red" dykem. haha Must have been late & I was tired.
I was HOPING the ether bit was a con, I could see the intake going into orbit at the same time the oil pan headed for china. :rollside:

[psdperformance]

riodog, yeah that ether bit was kind of funny. what i should have told you was to shove two ether cans up your ass and light your nose on fire :D
now that would be funny.
chris

[psdperformance]

Hey, riodog if you need any performance parts give me a call at 1800-230-3030 I have bought enough parts i should own or have stock in the company!!! :D I even remember the phone number :eek: Any ways if this motor does not turn out good i will be calling around to some of the numbers in the post. I should know by next weekend if it lives or dies. I just might sink the stupid boat and start fresh!
Later chris