TURBO!CB Competition Eliminators 48/40. Dyno and bent pushrod.

[JLH]

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.

[Erlend / bug66]

Picture time... Easier with something to look at



Try to figure out if someone is making offset rockers for one side?

[JLH]

Don't have pictures of the problem as we speak. Will take some when I'm back at the work shop 

[JLH]

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  

[Erlend / bug66]

I will make you a shopping list of what you new for a new transmission 

[JLH]

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?

[JLH]

I will make you a shopping list of what you new for a new transmission 

I need that too....make the shopping chart x2 

[richie]

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
 

[JLH]

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
 

[richie]

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.

[Fiatdude]

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)

[Martin S.]

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!

[Fiatdude]

Richard Clewett (310) 406-8788

[Martin S.]

Thanks! I just met a local who is also running Electromotive and he needs some help. Mine is still ok for now.

[dragvw2180]

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 .

[JLH]

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. 

[JLH]

It was fun as long as it lasted  

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.  

[JLH]

https://www.youtube.com/watch?v=Pc9AIrIQBP0

[Torben Alstrup]

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

[cassa]

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

[Martin S.]

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.

[JLH]

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. 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 

I do want to go dual taper, but no space for them before i machine the heads for more pushrodtube to pushrod clearance.

[JLH]

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) 

[JLH]

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. 

[BeetleBug]

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 

-BB-

[JLH]

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 

-BB-

 Do you remember what springs you change to? Where to get them?

Again, thanks for good input on my way 

[BeetleBug]

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 

-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-

[Taylor]

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.

[Torben Alstrup]

 I have a set of those Bugpack springs and retainers on the shelf.
PM me if interested.

[JLH]

I have a set of those Bugpack springs and retainers on the shelf.
PM me if interested.

Thanks, I will contact you if needed.