Title: TURBO!CB Competition Eliminators 48/40. Dyno and bent pushrod. Post by: JLH on August 23, 2017, 13:41:57 pm Hello, Joakim from Norway here.
I'm having a problem getting clearance between my pushrods and pushrod tubes on my Competition Eliminator heads 48/40 valves. Knowing the moved valve guides are not doing this any easier, I wonder if you have some recommendations on Rockers/rocker assembly to run with these heads to maybe eliminate the problem instead of machining the heads where the pushrod tubes are seated? The pushrods are now gently rubbing, causing a leak between the head and the pushrod tube (cyl 1 and 2 are the most tight/most issue). I have tried to shim the rockers to get as most clearance I can get without hitting the valve too far to the left of the valve center, but still not enough clearance to avoid rubbing and oil leaks. So do any of you have any tips, tricks or parts recommendations to easy my problems and put me in to the right direction to eliminate my low clearance, rubbing and leaks? Would love to not take the engine out of the car again to machine the heads. Valve/rocker geometry is as good as it gets. List of engine specs: CB Competition Eliminator 48/40. 1:1.4 rockers (Think they are CB but bought second hand, so could be wrong). CB Cromo pushrods (cut to length). Valve-caps. Fast Fab pushrod tubes. Engle FK89 Camshaft. 94mm bore. 76mm CB crankshaft. (2110ccm) 5.5 h-beam rods. 8.7 compression ratio. (2.1mm deck height, 54CC) Running hideaway turbo, watercooled Intercooler, EFI and pumpgas/E85. (Car has not been driven yet, freshly built and soon going for the dyno) More you need to know? Hope someone could help, I'm stuck trying to figure out what to do. Next step Is to tear down the engine and machine the heads for clearance. (Also contacted CB for some input/suggestions) Thanks! Joakim/Norway. Title: Re: CB Competition Eliminators 48/40, Pushrod/Pushrodtube clearance. Rocker's? Post by: Erlend / bug66 on August 23, 2017, 13:45:05 pm Picture time... Easier with something to look at
Try to figure out if someone is making offset rockers for one side? Title: Re: CB Competition Eliminators 48/40, Pushrod/Pushrodtube clearance. Rocker's? Post by: JLH on August 23, 2017, 13:50:21 pm Don't have pictures of the problem as we speak. Will take some when I'm back at the work shop ;)
Title: Re: CB Competition Eliminators 48/40, Pushrod/Pushrodtube clearance. Rocker's? Post by: JLH on August 23, 2017, 13:56:31 pm Me, Erlend +++ looking at some "tunes" after first ever start up. This happend in the pit area at SCC 2017. A good feeling but long way to go. Did not manage to make a run, but 2018 will be awesome 8)
Title: Re: CB Competition Eliminators 48/40, Pushrod/Pushrodtube clearance. Rocker's? Post by: Erlend / bug66 on August 23, 2017, 13:59:48 pm I will make you a shopping list of what you new for a new transmission ::)
Title: Re: CB Competition Eliminators 48/40, Pushrod/Pushrodtube clearance. Rocker's? Post by: JLH on August 23, 2017, 14:01:07 pm Picture time... Easier with something to look at Try to figure out if someone is making offset rockers for one side? Yes, offset rockers for one or both sides would be great. But also need input on what rockers people are running. I'm not the only one running these heads. Pretty sure someone else also have had to handle this problem? Title: Re: CB Competition Eliminators 48/40, Pushrod/Pushrodtube clearance. Rocker's? Post by: JLH on August 23, 2017, 14:01:46 pm I will make you a shopping list of what you new for a new transmission ::) I need that too....make the shopping chart x2 ::) ;D :D Title: Re: TURBO!CB Competition Eliminators 48/40, Pushrod/Pushrodtube clearance. Rocker's? Post by: richie on August 23, 2017, 16:50:27 pm Hi Joakim
I am using Scats on one car and CBs with the 67 nitrous car, fast fab tubes, and straight mantons on both, part of the problem I think you have is the short stroke, this equals a narrow engine so angle for pushrods is exaggerated. Where does it leak? head end? do you use sealant on tube seals? if not a generous amount around the head end seal before install will help as the tube is at a bad angle as well and the seal doesn't sit straight in the head so slightest movement can cause a leak, the sealant helps add more sealing area on the edge that barely seals cheers Richie Title: Re: TURBO!CB Competition Eliminators 48/40, Pushrod/Pushrodtube clearance. Rocker's? Post by: JLH on August 23, 2017, 18:18:13 pm Thanks. The short stroke as you say do also make it tighter as the angle on the pushrods and tubes are more aggressive. I have used some sealant on the tubes, but will check again. Clean them up and mount them with some new and fresh sealant and at the same time see if the rubbing has been very bad or just slightly. My leak is at the heads, on cyl 1 at this point. After around 15-20 minutes running you can see oil collecting under pushrod tubes on cyl1 and making some smoke when it drips down on the j-tube/exhaust.
Hi Joakim I am using Scats on one car and CBs with the 67 nitrous car, fast fab tubes, and straight mantons on both, part of the problem I think you have is the short stroke, this equals a narrow engine so angle for pushrods is exaggerated. Where does it leak? head end? do you use sealant on tube seals? if not a generous amount around the head end seal before install will help as the tube is at a bad angle as well and the seal doesn't sit straight in the head so slightest movement can cause a leak, the sealant helps add more sealing area on the edge that barely seals cheers Richie Title: Re: TURBO!CB Competition Eliminators 48/40, Pushrod/Pushrodtube clearance. Rocker's? Post by: richie on August 23, 2017, 20:25:54 pm Use a sealant that will dry hard but stay a little flexible, I use Permatex Ultra grey on my builds, you can even go in from rocker side after the tubes are installed and wipe some round top of tube from that side.
Title: Re: TURBO!CB Competition Eliminators 48/40, Pushrod/Pushrodtube clearance. Rocker's? Post by: Fiatdude on August 24, 2017, 00:49:34 am I like your setup -- -- I'd recommend Pauter push rod tubes -- Crawford had the biggest and best tubes, but he has retired and closed his business (I got the last set)
(https://www.thesamba.com/vw/gallery/pix/1683607.jpg) Title: Re: TURBO!CB Competition Eliminators 48/40, Pushrod/Pushrodtube clearance. Rocker's? Post by: Martin S. on August 24, 2017, 17:36:00 pm What do you mean short stroke? Is 76 crank considered short? Fiatdude, a while back you mentioned someone who can tune Electromotive over the internet. Do you have a contact for him? Thanks!
Title: Re: TURBO!CB Competition Eliminators 48/40, Pushrod/Pushrodtube clearance. Rocker's? Post by: Fiatdude on August 25, 2017, 00:04:47 am Richard Clewett (310) 406-8788
Title: Re: TURBO!CB Competition Eliminators 48/40, Pushrod/Pushrodtube clearance. Rocker's? Post by: Martin S. on August 25, 2017, 16:39:34 pm Thanks! I just met a local who is also running Electromotive and he needs some help. Mine is still ok for now.
Title: Re: TURBO!CB Competition Eliminators 48/40, Pushrod/Pushrodtube clearance. Rocker's? Post by: dragvw2180 on September 08, 2017, 14:29:11 pm You did not mention which pushrods you were using so I am assuming you are using straight type pushrods . I use dual tapered Manton pushrods plus the pushrod seats have been moved when Dave Kawell built my heads . The pushrod tubes I use are CB Performance 1567 Racing Stainless steel Push Rod Tubes on my 2387 turbo street engine , no leaks and no rubbing .
Title: Re: TURBO!CB Competition Eliminators 48/40, Pushrod/Pushrodtube clearance. Rocker's? Post by: JLH on September 26, 2017, 08:02:47 am UPDATE.
I use straight type cromo CB pushrods. In the future i will take the heads of to machine them for more clearance (Move pushrodtube seating), but at this point I want to take it to the dyno first to see if it will hold up ::) I did as Richie said and put some extra sealant on the pushrod tube (intake cyl 1). All others are at this point dry. No leaks. When i inspected the valvtrain and the pushrodtubes, there was some rubbing on the tube intake cyl 1 and 2, but not that much on cyl 2. I have now been able to run the engine warm after some tuning and drove it 500m on the road to check the clutch and gears. Nice sound in the engine, everything looks dry (small leak from oilpump cover, will tight it up). Good throttle response on ''bad tune''. With fresh fuel and new 10/60 oil inside, I'm ready for the dyno. The time has come to see if I have manage to build a good engine. Can't wait. ;D Title: Re: TURBO!CB Competition Eliminators 48/40, Pushrod/Pushrodtube clearance. Rocker's? Post by: JLH on October 24, 2017, 15:21:32 pm It was fun as long as it lasted :P
Had some issues this weekend in the dyno but not mechanical before sunday. When Things really started to work out after some tuning issues and smaller bugs, it decided to bend a pushrod on exhaust cyl 2. Not been able to research the problem any futher at this moment. Just a bent pushrod as far as I can see. But what made it happen. Poor quality or mechanical problem causing to much pressure/force on the pushrod. That I will try to find out. The datalog shows no engine failure and no ignition knock (knock sensor and ''knock box'' headset). No signs of any valvefloat eather. Problem happened right after a full pull at 6690rpm 1.1 - 1.2kpa (15-18psi) boost with a short spike in the log at 1.4kpa (20psi) boost With very rich fuel (98 octane petrol, not E85) and ignition as low as 8.3 BTDC for a very short moment (not been able to tune so much ''in top'' of the scale). So back to the workshop to get it sorted before 2018 season. Still a good weekend, and I have learned a lot more. Got no power readings that ''counts'', but made one pull before we started some serious tuning. With basic boost (spring pressure 0.6 - 0.8kpa, 8-11psi), very Rich fuel and mild/basic ignition it made 225WHP/319NM With 6500rpm max. So can't wait to fix it and go back to the dyno. ;D Title: Re: TURBO!CB Competition Eliminators 48/40, Pushrod/Pushrodtube clearance. Rocker's? Post by: JLH on October 24, 2017, 15:43:55 pm https://www.youtube.com/watch?v=Pc9AIrIQBP0 Title: Re: TURBO!CB Competition Eliminators 48/40, Pushrod/Pushrodtube clearance. Rocker's? Post by: Torben Alstrup on October 24, 2017, 20:14:08 pm I bet you are using the 0,035" wall PR´s. What springs? K800? That is no good at all. You need much stronger PR´s with boost and those springs. You should go dual taper.
http://www.cbperformance.com/product-p/1629.htm Title: Re: TURBO!CB Competition Eliminators 48/40, Pushrod/Pushrodtube clearance. Rocker's? Post by: cassa on October 24, 2017, 21:10:59 pm Give Tor Øyvind Skinne a call.
He will hjelp you out with a set of his alu pushrods. They will stand up to the hardest abuse! He will deliver the ready assembled at the lenght you need. Reg Carsten Title: Re: TURBO!CB Competition Eliminators 48/40, Pushrod/Pushrodtube clearance. Rocker's? Post by: Martin S. on October 24, 2017, 21:17:16 pm As well, before throwing more money at it, double check your geometry and make sure it looks good. Careful, a fresh engine shouldn't be fully loaded until it breaks in and gets some carbon built up on the pistons to keep the heat away from the rings.
Title: Re: TURBO!CB Competition Eliminators 48/40, Pushrod/Pushrodtube clearance. Rocker's? Post by: JLH on October 24, 2017, 22:35:12 pm I bet you are using the 0,035" wall PR´s. What springs? K800? That is no good at all. You need much stronger PR´s with boost and those springs. You should go dual taper. http://www.cbperformance.com/product-p/1629.htm Yes, K800. This is what i have though about too. Too weak PR's. Story of the Engine build is it starter with "what do I have, and what do I need" and it has just been a "snowball" from that point. The PR's was some of the parts I had from the start, and unknown exactly what kind they was. So took a chance on them. :P A"prototype" build you could say. Learned a lot, and already know some more to do different and be aware of with the next build. But it is not just trowed together ;) :D I do want to go dual taper, but no space for them before i machine the heads for more pushrodtube to pushrod clearance. :) Title: Re: TURBO!CB Competition Eliminators 48/40, Pushrod/Pushrodtube clearance. Rocker's? Post by: JLH on October 24, 2017, 22:40:56 pm Give Tor Øyvind Skinne a call. He will hjelp you out with a set of his alu pushrods. They will stand up to the hardest abuse! He will deliver the ready assembled at the lenght you need. Reg Carsten That i will do. Just have to machine the heads some over the winter. Going to do a minor tear down to be ready for 2018 season. But will put in some new cromo pushrods now, just to see if engine still is ok. (Yes, i will know this for sure by taking it apart also) :) Title: Re: TURBO!CB Competition Eliminators 48/40, Pushrod/Pushrodtube clearance. Rocker's? Post by: JLH on October 24, 2017, 22:44:50 pm As well, before throwing more money at it, double check your geometry and make sure it looks good. Careful, a fresh engine shouldn't be fully loaded until it breaks in and gets some carbon built up on the pistons to keep the heat away from the rings. Thanks for good input. The geometry should be ok. But everything getting double checked this winter. We are taking it nice and easy. Basic break-in are also done. :) Title: Re: TURBO!CB Competition Eliminators 48/40. Dyno and bent pushrod. Post by: BeetleBug on October 25, 2017, 09:12:07 am Been there - done that! Just forget using straight pushrods JLH. I also bent Mantons dual tapered ones with K800`s. It was not before I got rid of those K800`s and replaced them with some with a bit less pressure together with dual tapered Alu pushrods that I managed to get the parts to live on my old 2332 turbo engine.
Keep on with the good work... and please do not forget to ask questions. I`m pretty sure someone have done what you are doing before :D -BB- Title: Re: TURBO!CB Competition Eliminators 48/40. Dyno and bent pushrod. Post by: JLH on October 25, 2017, 19:48:52 pm Been there - done that! Just forget using straight pushrods JLH. I also bent Mantons dual tapered ones with K800`s. It was not before I got rid of those K800`s and replaced them with some with a bit less pressure together with dual tapered Alu pushrods that I managed to get the parts to live on my old 2332 turbo engine. Keep on with the good work... and please do not forget to ask questions. I`m pretty sure someone have done what you are doing before :D -BB- Do you remember what springs you change to? Where to get them? Again, thanks for good input on my way :) Title: Re: TURBO!CB Competition Eliminators 48/40. Dyno and bent pushrod. Post by: BeetleBug on October 25, 2017, 19:53:59 pm Been there - done that! Just forget using straight pushrods JLH. I also bent Mantons dual tapered ones with K800`s. It was not before I got rid of those K800`s and replaced them with some with a bit less pressure together with dual tapered Alu pushrods that I managed to get the parts to live on my old 2332 turbo engine. Keep on with the good work... and please do not forget to ask questions. I`m pretty sure someone have done what you are doing before :D -BB- Do you remember what springs you change to? Where to get them? Again, thanks for good input on my way :) Indeed I do, they came from BugPack and was labeled Chevy Springs. That was it basically. I did however test them and they gave me approx 150 lbs in the seat and 385bs at max lift with the FK87. The K800`s was 450lbs at max lift. -BB- Title: Re: TURBO!CB Competition Eliminators 48/40. Dyno and bent pushrod. Post by: Taylor on October 26, 2017, 05:47:25 am The comp eliminators I have from Head's Up Performance have welding done on the exhaust pushrod holes and they have been opened up and moved over a little. Exhaust valves moved out .100" on these as well. No leaks and no rubbing.
Title: Re: TURBO!CB Competition Eliminators 48/40. Dyno and bent pushrod. Post by: Torben Alstrup on October 26, 2017, 21:59:35 pm I have a set of those Bugpack springs and retainers on the shelf.
PM me if interested. Title: Re: TURBO!CB Competition Eliminators 48/40. Dyno and bent pushrod. Post by: JLH on October 27, 2017, 13:51:44 pm I have a set of those Bugpack springs and retainers on the shelf. PM me if interested. Thanks, I will contact you if needed. :) Title: Re: TURBO!CB Competition Eliminators 48/40. Dyno and bent pushrod. Post by: JLH on October 27, 2017, 14:02:33 pm I have talked a bit to CB/Mike Lawless (E-mail) asking about their Race Master Valve Springs if they fit and what type of pressure they are rated to, and also what type of pushrods they recommended. This because almost everything used in head/valve train is CB products except from cam and lifters. He recommended to stay with the K800's (gave him all my engine specs) and use the dual taper cromoly push rods:
Take a look at the #1629 Dual taper push rods. These are a lot stronger than the ones you were running and will hold up to the k-800 valve springs. http://www.cbperformance.com/product-p/1629.htm The K-800 is what I would recommend for your engine. So......Heads are going off anyway to make more clearance. Good the winter is long so I can get things sorted one and all. ;D A spring change and dual taper alu pushrods are in mind ;) Title: Re: TURBO!CB Competition Eliminators 48/40. Dyno and bent pushrod. Post by: SSRT on November 27, 2017, 23:17:03 pm "ignition as low as 8.3 BTDC for a very short moment"
This might be the problem... Title: Re: TURBO!CB Competition Eliminators 48/40. Dyno and bent pushrod. Post by: Erlend / bug66 on November 28, 2017, 00:43:27 am Go with v8 springs. All the springs in the world to choose from.
I’ll check the name on mine. They are perfect for your engine Title: Re: TURBO!CB Competition Eliminators 48/40. Dyno and bent pushrod. Post by: Martin S. on November 28, 2017, 17:06:11 pm Apparently the BMW guys like to use our air-cooled VW springs :D
Title: Re: TURBO!CB Competition Eliminators 48/40. Dyno and bent pushrod. Post by: Martin S. on November 28, 2017, 17:46:52 pm "ignition as low as 8.3 BTDC for a very short moment" This might be the problem... This is a good point. Can you post your data logs of the run just before the bent pushrod? Title: Re: TURBO!CB Competition Eliminators 48/40. Still alive. Post by: JLH on December 11, 2017, 08:35:29 am Short update after a long pause from the garage. Engine is still OK and gives no sign of damage other then a bent pushrod. Engine turns smooth and runs great. Even in this cold Winter weather 3-4C. Now time to take it out to machine the heads for more pushrod to pushrod tube clearance ;D
Title: Re: TURBO!CB Competition Eliminators 48/40. No more rubbing pushrods. Post by: JLH on July 06, 2018, 11:53:04 am Update.
The heads got some machine work on them and we ended up moving the holes for the tubes to seat in, by making a new chamfer for the PR gasket off center from the original center of the hole. That's the short way to tell the story, but was some hours making it happen. But now i have no rubbing at all!!! Running tapered alu pushrods on K800 springs. Have done some low boost tuning and ended up with 307whp, 424nm at 7400rpm max (for now) WITH 14,5 PSI and pump gas. Can't wait to get some E85 in there and more boost. ::) |