ando76

Oh yes Q. You have that right. Life would be a lot easier with them. Oh wait a minute. I have them.  Lol. 
Most of my customers still love carbs and it's really hard to get them to commit to efi on these things.  I do however have a bloke keen on fitting the heritage series Jenvey efi throttle bodies to his 250 2v. 

Yep. And they are part of the solution we have come up with, but they still pull over. It's not as bad, but it still happens as the route cause is still there, no matter what part you fit to the carb. 
BLP carb in America sell a whole lot of stuff aimed at dealing with it. Yes they help, but they don't eliminate it. You don't want to know how much it cost to learn that fact. 

Oh yes Q. You have that right. Life would be a lot easier with them. Oh wait a minute. I have them.  Lol. 
Most of my customers still love carbs and it's really hard to get them to commit to efi on these things.  I do however have a bloke keen on fitting the heritage series Jenvey efi throttle bodies to his 250 2v. 

Oh yes Q. You have that right. Life would be a lot easier with them. Oh wait a minute. I have them.  Lol. 
Most of my customers still love carbs and it's really hard to get them to commit to efi on these things.  I do however have a bloke keen on fitting the heritage series Jenvey efi throttle bodies to his 250 2v. 

Here you go, easy way to deal with it, Tried and tested:


You're welcome =P

 

The amount of airspeed past the Venturi does have an effect on when it occurs. On Daves 2 barrel crossy, it was at 3500. They just went complete open circuit and poured the fuel in.  Being a restrictor class engine it's forced to run the visually standard manifold and 350 Holley. It runs one of Cams heads so the airspeed is just ridiculous off the bottom. Which obviously made it ten times worse. 
 

The mounts are only one part of the whole system to address the actual cause.  All the rest of the stuff, like he talks about at the end of the video, just treats the symptoms. 
Through each step we were able to lift the rpm point at which it started to 'pull over' but it wasn't until a big bit of lateral thinking happened, and yes it did involve several beers, that we actually cured it. I say we as Dave from Clarko's Performance was part of the process as it was his 2 barrel mud flicker that started the journey. Cam also played a part as did Brenton from Boetchhers and even my nephew who is studying mechanical engineering. Josh has also,played a massive part as he has been doing the endurance testing of the four barrel kit.  I like to ensure the function and durability of all the products I develop before I try and retail them. 

Yep. That's it. Fuel pullover through the squirters. It does chronic things to mixtures and afr as outlined in old mates you tube video. 
It turns the accelerator pump squirters into a fuel injector. They just go open circuit. It's one of the most bizarre things I've seen on the dyno. Had a 2 barrel and 4 barrel crossy both do it.  Last time I was at Boetchhers on their hub dyno, Brenton their main brain and engine dude couldn't believe it.  He actually made me run the car up a couple of times so he could video it.  It's not something that occurs on their big dollar, US sourced v8's.  It actually does occur on very high revving v8 engines. 
 

The amount of airspeed past the Venturi does have an effect on when it occurs. On Daves 2 barrel crossy, it was at 3500. They just went complete open circuit and poured the fuel in.  Being a restrictor class engine it's forced to run the visually standard manifold and 350 Holley. It runs one of Cams heads so the airspeed is just ridiculous off the bottom. Which obviously made it ten times worse. 
 

The mounts are only one part of the whole system to address the actual cause.  All the rest of the stuff, like he talks about at the end of the video, just treats the symptoms. 
Through each step we were able to lift the rpm point at which it started to 'pull over' but it wasn't until a big bit of lateral thinking happened, and yes it did involve several beers, that we actually cured it. I say we as Dave from Clarko's Performance was part of the process as it was his 2 barrel mud flicker that started the journey. Cam also played a part as did Brenton from Boetchhers and even my nephew who is studying mechanical engineering. Josh has also,played a massive part as he has been doing the endurance testing of the four barrel kit.  I like to ensure the function and durability of all the products I develop before I try and retail them. 

Yep. That's it. Fuel pullover through the squirters. It does chronic things to mixtures and afr as outlined in old mates you tube video. 
It turns the accelerator pump squirters into a fuel injector. They just go open circuit. It's one of the most bizarre things I've seen on the dyno. Had a 2 barrel and 4 barrel crossy both do it.  Last time I was at Boetchhers on their hub dyno, Brenton their main brain and engine dude couldn't believe it.  He actually made me run the car up a couple of times so he could video it.  It's not something that occurs on their big dollar, US sourced v8's.  It actually does occur on very high revving v8 engines. 
 

Nah it's a tune issue. The rigidness of those styles is one of the things that leads to chronic fuel pull over.  Type fuel pull over into you tube and you will see what I'm talking about.  
After much research I've found a way to totally eliminate it. There are plenty of products on the market aimed at curing it, but they are all based around mods to the carb. None of them truly eliminate it.  What I have done does. The cars idle and start better, are way easier to tune and make more power.  No more 'tune out as best as you can and send it out, the customer will never know'.  
The four barrel kit will be available early next year as I'm happy with the endurance testing now.  The main part of the  2 barrel kits have been machined and are on their way back from Malaysia.  Sadly we had to send them overseas as making them here was just not viable. 

Nah it's a tune issue. The rigidness of those styles is one of the things that leads to chronic fuel pull over.  Type fuel pull over into you tube and you will see what I'm talking about.  
After much research I've found a way to totally eliminate it. There are plenty of products on the market aimed at curing it, but they are all based around mods to the carb. None of them truly eliminate it.  What I have done does. The cars idle and start better, are way easier to tune and make more power.  No more 'tune out as best as you can and send it out, the customer will never know'.  
The four barrel kit will be available early next year as I'm happy with the endurance testing now.  The main part of the  2 barrel kits have been machined and are on their way back from Malaysia.  Sadly we had to send them overseas as making them here was just not viable. 

Nah it's a tune issue. The rigidness of those styles is one of the things that leads to chronic fuel pull over.  Type fuel pull over into you tube and you will see what I'm talking about.  
After much research I've found a way to totally eliminate it. There are plenty of products on the market aimed at curing it, but they are all based around mods to the carb. None of them truly eliminate it.  What I have done does. The cars idle and start better, are way easier to tune and make more power.  No more 'tune out as best as you can and send it out, the customer will never know'.  
The four barrel kit will be available early next year as I'm happy with the endurance testing now.  The main part of the  2 barrel kits have been machined and are on their way back from Malaysia.  Sadly we had to send them overseas as making them here was just not viable. 

They will be fine on a v8. It's solely an i6, 2 or 4 barrel issue. Doesn't happen on Weber equipped i6 engines. 

Xd versions of these engines had no centre bolt from memory.  I will stand corrected tho. We run extended 9/16unf bolts on the race motors for vac pump drive mandrels and ps pulleys and they never come undone. Hence my harmonics comment. I wasn't being a smart arse. Well maybe a little 

If the threads in the crank are fine, and the bolt (9/16 unf on early and metric crap on late model cranks) check out then I'd be looking at harmonics or just loctite it and hope. 

Yeah definitely going back to the builder second time now even after its second rebuild and I don't want to fuck it it again because I'm not building in for the 3rd time aha

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Did someone say harmonics.......

They do awesome work at a fair price. I sent another customer engine down to them last week. It got there Monday and they are onto it.  

Yup as above and give the ironhead to ando so he can flow test it for shits n giggles!!! Coz ironhead is missing from the flowbench section lol

I'm with Greg. Zero deck with those pistons and a c2 head would yield very nice compression.  I've taken big hp and torque blocks to .060 and I know others have taken them further so be guided by that. 
Balance is pretty much a must if you want reliable trouble free running on these old girls. Factory tolerance on these things was very wide. 
Id be using that engine as a base for sure, especially if it's fresh. They generally have anything from .045-.050 deck height so giving them a mow, even with the dish pistons, nets good comp. add in a c2 with .040 off it and your in good comp territory if it's .040 over 

Bang for buck the BA/BF & FG motors make more hp. That's a given. We race against several up here. Most get 275rwhp with just cams and tune on $300 wrecker motors.  
You have to love crossflow engines to want to make power from them as they are very expensive to build to that same power level. They are after all a very old engine.  
Funny thing is in our form of Motorsport the crossy's still dominate the ba/bf. why? because of their torque and the weight penalty that comes with the Barra. 
At the end of the day the buyer will make the choice. I've got several customer crossflow engine builds on the go at the moment so the interest in them is still there. I make a point of informing all my customers at the very outset that it's not going to be a cheap exercise.
 

Bang for buck the BA/BF & FG motors make more hp. That's a given. We race against several up here. Most get 275rwhp with just cams and tune on $300 wrecker motors.  
You have to love crossflow engines to want to make power from them as they are very expensive to build to that same power level. They are after all a very old engine.  
Funny thing is in our form of Motorsport the crossy's still dominate the ba/bf. why? because of their torque and the weight penalty that comes with the Barra. 
At the end of the day the buyer will make the choice. I've got several customer crossflow engine builds on the go at the moment so the interest in them is still there. I make a point of informing all my customers at the very outset that it's not going to be a cheap exercise.
 

Bang for buck the BA/BF & FG motors make more hp. That's a given. We race against several up here. Most get 275rwhp with just cams and tune on $300 wrecker motors.  
You have to love crossflow engines to want to make power from them as they are very expensive to build to that same power level. They are after all a very old engine.  
Funny thing is in our form of Motorsport the crossy's still dominate the ba/bf. why? because of their torque and the weight penalty that comes with the Barra. 
At the end of the day the buyer will make the choice. I've got several customer crossflow engine builds on the go at the moment so the interest in them is still there. I make a point of informing all my customers at the very outset that it's not going to be a cheap exercise.