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    Page 31 of 37 FirstFirst ... 21 26 27 28 29 30 31 32 33 34 35 36 ... LastLast
    Results 601 to 620 of 721
    1. #601
      Join Date
      Feb 2016
      Location
      SoCal
      Posts
      475
      Lance - Do you have stock pistons in the engine? If so, my bet is going to be that you popped the top of the piston, on #4 at that.

      1970 VW Bug - Just your average mid engine Bug
      Track toy - 06 Evo - E85 and lots of boost
      Newest track toy - 2021 Supra


    2. #602
      Join Date
      Aug 2012
      Location
      Peoria, AZ
      Posts
      1,758
      Country Flag: United States
      Quote Originally Posted by Bugzilla View Post
      Lance - Do you have stock pistons in the engine? If so, my bet is going to be that you popped the top of the piston, on #4 at that.
      Yup, stock Hypereutectic Aluminum pistons. While you may be right, the pumping of air into the cooling system how is the other question then.
      Lance
      1985 Monte Carlo SS Street Car

    3. #603
      Join Date
      Feb 2016
      Location
      SoCal
      Posts
      475
      While I hope I am very wrong, I have seen a lot of times that when the piston comes apart, it cracks the sleeve too.... That would also explain why you dont really see oil in the coolant.
      1970 VW Bug - Just your average mid engine Bug
      Track toy - 06 Evo - E85 and lots of boost
      Newest track toy - 2021 Supra

    4. #604
      Join Date
      Aug 2012
      Location
      Peoria, AZ
      Posts
      1,758
      Country Flag: United States
      I am mentally prepared for that...as a worst case scenario. Actually worst case would be if the head was damaged in some sort as the heads are the jewel of this engine.

      What gives me slight hope that isn't the case is it still ran VERY well, idled smooth and pulled great down back straight right up until I pulled off the track. It also started slowly as it's been pushing coolant out the recovery tank cap for a couple of events now. It even had great power off idle as I pulled it up onto trailer and back off and into garage once I got home. If it had a large loss of compression or a completely broke apart piston...I think I would have noticed it running on 7 during those times after I brought it off track.
      Lance
      1985 Monte Carlo SS Street Car

    5. #605
      Join Date
      Oct 2018
      Location
      Phoenix, AZ
      Posts
      584
      Country Flag: United States
      Broken piston is kinda obvious in my limited experience. From what you told me when we were talking Lance, I'm pretty sure there is no hardware damage unless the bore cracked. Even then I don't think it is anything major. Everything you've mentioned here and on the phone points to just popping the heads off and refreshing the surfaces with new gaskets. Then away you go.

      This is one of those things where we will play all the worst case scenarios until you dive in. You need a hand or just a kick? haha
      '95 F-150 track ready street beast
      Want more projects/photos? Check my Instagram

    6. #606
      Join Date
      Aug 2019
      Location
      Nashville, TN
      Posts
      64
      Country Flag: United States
      I’ve been following this one closely. Can be heartbreaking to lose an engine- so I feel for ya. It sounds like this could end up being relatively minor, so fingers crossed.

      Is there a link to an engine build thread for this vehicle? I’m curious what kind of animal you’re working with.

    7. #607
      Join Date
      Aug 2012
      Location
      Peoria, AZ
      Posts
      1,758
      Country Flag: United States
      Quote Originally Posted by TanMan View Post
      I’ve been following this one closely. Can be heartbreaking to lose an engine- so I feel for ya. It sounds like this could end up being relatively minor, so fingers crossed.

      Is there a link to an engine build thread for this vehicle? I’m curious what kind of animal you’re working with.

      It's not really heartbreaking for me as much as it is just a time suck. I don't like taking the car off the road for an extended time which a short block change would do.

      The engine started life as a HT383 crate engine from GMPP. Bottom end is basically a forged crank with 3.8" stroke, 4.0" bore filled with powdered metal rods and Hyper aluminum pistons. Was 9.7:1 comp ratio with stock iron vortec heads.

      We rebuilt it about 4 years ago, squared the block up decking it a bit, new rings and bearings with a slight hone, added worked over Fastburn heads and a custom ground Comp cam. Made 467 hp at 5400 RPM, 525 ft lbs at 4700 RPM on engine dyno with quadrajet and dual plane intake and still pulls 20" of vacuum at idle. Had over 400 ft lbs at 2000 RPM.

      Last summer I swapped on a Holley Terminator EFI and felt like we added 50 hp to it once we really dialed the tune in. It was running AWESOME and made great power everywhere.
      Lance
      1985 Monte Carlo SS Street Car

    8. #608
      Join Date
      Aug 2012
      Location
      Peoria, AZ
      Posts
      1,758
      Country Flag: United States
      More progress made today.

      Figured out a way to pull the engine with car on the lift.



      All kinds of room



      Here is passenger side head. All looks good, just a bit more oil on #4 exhaust valve.



      Tops of all of the pistons look normalish as do the cylinder walls.



      This is #4, the one in question.



      Popped #4 out and found this.







      Multiple rings are broken in multiple spots and the top edge of the piston has started melting away. Hard to tell what happened first, oil ring could have failed, let oil in chamber which may have raised compression just enough to cause detonation raising temps above what piston could handle. One or multiple rings could have been just a bit tight, got a bit too hot and broke causing loss of compression. Or something with cooling system could have caused an air pocket, causing that cylinder to get just a bit hot and start the meltdown. It'll be interesting to see if any rings are broken in any other cylinders, haven't pulled any other pistons out yet.

      Everything else looks excellent though. Bottom of pan was clean, cylinder walls are unscathed, head gasket looked good, basically you wouldn't know there was problem if not for that one piston. So glad I stopped when I did, that piston was one straight away from exploding.

      Bearings look pretty good still.



      I won't, but I literally could put a new piston with new rings on that rod and bolt it all back together again and I'm sure it would be fine.

      More than likely unless it's stupid expensive it'll get new forged rods and pistons and a refresh on the bearings and rings and a good clean up. I may even consider a cam change to bring things more in line with the rest of the build. We'll see.

      No hurry to put it back together though, it needs a new clutch disc and I may put a new accessory drive setup on the front as well as the engine refresh so this will be a bit of an extended project. Pretty dang happy I still have so many good parts left though, could have been much worse.
      Lance
      1985 Monte Carlo SS Street Car

    9. #609
      Join Date
      Feb 2016
      Location
      SoCal
      Posts
      475
      How that piston stayed together, I have no idea..... glad to see it didnt come apart! Super close but safe! Block is ok I take it? No signs of where the coolant loss was coming from?
      1970 VW Bug - Just your average mid engine Bug
      Track toy - 06 Evo - E85 and lots of boost
      Newest track toy - 2021 Supra

    10. #610
      Join Date
      Aug 2012
      Location
      Peoria, AZ
      Posts
      1,758
      Country Flag: United States
      Crazy isnt it? I didnt see the second crack with my eyes, only noticed it when I blew the pic up.

      The radiator was low on coolant, still havent figured out why recovery tank didnt drain back into radiator.

      The head bolt between 4 and 6 was "loose" compared to the others and there is that strange discoloration on #6 piston near that head bolt. I'm thinking this may have been the start of the bad things. Block seems to be fine but it'll get a good going over for sure.
      Lance
      1985 Monte Carlo SS Street Car

    11. #611
      Join Date
      May 2018
      Location
      way east on a rock
      Posts
      155
      With the cup half full theory, you now have the opportunity to make it more bulletproof with some good forged parts and more power. Yeah. More power

    12. #612
      Join Date
      Oct 2018
      Location
      Phoenix, AZ
      Posts
      584
      Country Flag: United States
      Never thought I'd say this about a broken piston, but that was LUCKY! Glad you tore it down to really look it over. I suppose you found the limits of non-forged internals. Going forged now is probably the best bet.
      '95 F-150 track ready street beast
      Want more projects/photos? Check my Instagram

    13. #613
      Join Date
      Mar 2014
      Location
      Yuma, AZ
      Posts
      635
      Country Flag: United States
      Hypers are ok until they get rattled, then they are a time bomb. Glad nothing worse happened.
      Nelson
      1969 Chevelle "Cone Smasher" Family Project
      https://www.pro-touring.com/threads/...uot?highlight=

      1984 "Rustang" GT, 5.0, 5 Speed Project
      https://www.pro-touring.com/threads/...T-(Slow-Build)

    14. #614
      Join Date
      Apr 2001
      Location
      The City of Fountains
      Posts
      15,971
      Country Flag: United States
      Quote Originally Posted by SSLance View Post
      More progress made today.



      More than likely unless it's stupid expensive it'll get new forged rods and pistons and a refresh on the bearings and rings and a good clean up. I may even consider a cam change to bring things more in line with the rest of the build. We'll see.

      No hurry to put it back together though, it needs a new clutch disc and I may put a new accessory drive setup on the front as well as the engine refresh so this will be a bit of an extended project. Pretty dang happy I still have so many good parts left though, could have been much worse.
      Please don't change the cam...LOL

      We got that tune down very nicely, and a new cam will necessitate a tuning change. Plus, I love how mild this cam is and I think you do as well.

      Andrew
      1970 GTO Version 3.0
      1967 Cougar build
      GM High-Tech Performance feature
      My YouTube Channel Please Subscribe!
      Instagram @projectgattago
      Dr. EFI
      I deliver what EFI promises.
      Remote Holley EFI tuning.
      Please get in touch if I can be of service.

      "You were the gun, your voice was the trigger, your bravery was the barrel, your eyes were the bullets." ~ Her

    15. #615
      Join Date
      Aug 2012
      Location
      Peoria, AZ
      Posts
      1,758
      Country Flag: United States
      Quote Originally Posted by andrewb70 View Post
      Please don't change the cam...LOL

      We got that tune down very nicely, and a new cam will necessitate a tuning change. Plus, I love how mild this cam is and I think you do as well.

      Andrew
      Yes, I do love it how it is, just wondering if now with the more info we have about the heads if we couldn't make it a bit less peaky is all.

      I'm not looking to make a huge change and if it looks like all we'll do is give up one thing to gain another, I'll probably leave it as is.

      I am wondering what a slight bump in compression ratio might do to the tune though? It's around 10.1:1 now and it's looking like going to a forged piston might bump it up to the 10.5:1ish range (or higher).
      Lance
      1985 Monte Carlo SS Street Car

    16. #616
      Join Date
      Apr 2001
      Location
      The City of Fountains
      Posts
      15,971
      Country Flag: United States
      A small bump in compression probably won't effect the tune much.

      Andrew
      1970 GTO Version 3.0
      1967 Cougar build
      GM High-Tech Performance feature
      My YouTube Channel Please Subscribe!
      Instagram @projectgattago
      Dr. EFI
      I deliver what EFI promises.
      Remote Holley EFI tuning.
      Please get in touch if I can be of service.

      "You were the gun, your voice was the trigger, your bravery was the barrel, your eyes were the bullets." ~ Her

    17. #617
      Join Date
      Aug 2012
      Location
      Peoria, AZ
      Posts
      1,758
      Country Flag: United States
      Spent a week or so investigating, diagnosing and soul searching. One thing I found changed the direction I thought i was heading more than anything else.

      When I pulled the rest of the pistons out yesterday, I found this broken ring land in #8.



      Everything else about that cylinder was normal as could be.

      This tells me that the top end we put together simply outpowered the bottom end and the weakest link (cast pistons) is what gave up first.

      Since the block is a 4.005" bore, there is no forged off the shelf piston that will work with it, so machine work it is. This actually helps though because now I can do the machine work to match the parts I pick out...instead of the other way around.

      I'm still very happy with the power this combo made so I'll not be making any drastic changes to the recipe, just fortifying some of the weaker parts inside and putting it all back together once again. It'll just take a bit longer and cost a bit more is all.
      Lance
      1985 Monte Carlo SS Street Car

    18. #618
      Join Date
      Aug 2012
      Location
      Peoria, AZ
      Posts
      1,758
      Country Flag: United States
      It has now been 48 days since I hurt the engine in Barney taking it off the road.

      I typically try to not take it off the road for longer than 3 weeks at any one time. Careful planning and working fast helps me get the car back on the road ready to enjoy quickly. The EFI swap took about 7 weeks which was longer than normal, but it was a HUGE job.

      I have to say, it is really starting to bug me that I haven't even decided on a path to repair yet, much less actually started buying parts and getting things done. This will be the longest this car has been down since I first restored the underside of it back in 2008. I said there would be no hurry as race season was basically done for me anyway, then this whole Covid-19 deal happened...but I'm ready to get it moving forward soon I hope.

      I've met a local machinist that is working on some pricing for me. Soon then after I'll be making some final decision on which path to take.

      Meanwhile...I'll keep working on the Jeep.

      Stay safe everyone...
      Lance
      1985 Monte Carlo SS Street Car

    19. #619
      Join Date
      Oct 2018
      Location
      Phoenix, AZ
      Posts
      584
      Country Flag: United States
      I never would have guessed that your car would be down the at time time my project hit the road. Glad to hear you are working through the options.

      One other bright side of this pandemic is all the companies offering short blocks are running discounts....just sayin.
      '95 F-150 track ready street beast
      Want more projects/photos? Check my Instagram

    20. #620
      Join Date
      Aug 2012
      Location
      Peoria, AZ
      Posts
      1,758
      Country Flag: United States
      This car has been super reliable for a long time, it's taken it's beatings like a champ.

      I could have had it back together already if I had taken a couple different paths, I just wasn't ready to make those decisions without a lot of thought. No regrets yet, just bummed I can't take it out for drives now is all. Your videos of you driving your truck around Sean aren't helping either!!! :D
      Lance
      1985 Monte Carlo SS Street Car

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