Jenvey Heritage throttle bodies anyone?

Thanks Eric! What are the advantages of these pistons over Mahle's? Are there matching rods available?

Forged pistons are stronger than cast pistons and the Mahles are cast pistons.

Forged pistons are heavier and that's why we sourced the strongest lightest wrist pins we could find, but my pistons are still heavier.

AFAIK, no one makes connecting rods for the 6 bolt pushrod motors as there is almost no demand, so when needed, we have to have them custom made.

Thanks Eric... you're always so helpful! Do you have the valve spring kit in stock?

I have stock valve springs in stock and I usually have dual valve springs and valve spring retainers too.

Which do you want?

Rocker

The rocker spring kit

Thanks

Oh, you mean the rocker shaft spacer kit that replaces the springs that hold the rockers apart.

I am pretty sure I have a set for a B18/B20.

JohnMc said:

I don't know how DCOE's compare to ITB's, specifically DCOE style ITB's (same manifold and throttle placement), but the DCOE's are a freaking hoot to drive. I did play around with the linkage angles when I first installed them (lololol at my first attempt!) but it's pretty good now. It's just a very sharp and instant throttle response. so that can be somewhat hard to deal with. The old SU's always had a sort of muted response.

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My point exactly that low angle inrush is huge and gives a false impression of power increase, just like over carburation, when in fact there is a loss of torque. The CV has to open that is why SU carbs feel soft.

DCOE's are individual runners, so they behave similar to ITB. And will likely exihbit the same false impression of power due to the snappy response.

I did a lot of R&D on butterfly air valves. I was working with a friend who patented a smooth bore throttle valve. we were focussing on injected dirt car stuff. Many of them needed huge ITB cross sections to not chop the top off the power band. (Due to the air flow disruption of the butterfly valve) And the object was to reduce the size of the runner (360 class limits the intake cross section to stop racers from building stupid high rpm motors that could dominate). His idea was to eliminate the oversized ITB and the air flow loss of the butterfly valve and make more power with an optimized intake port that did not reduce flow and velocity. With a smaller volume it actually flowed more air than the big ITB. It's patented but never went much past the R&D stages. Some big players took a look at it but it never took off, difficult to manufacture. Many are making intake runners now that have moved the butterfly valve up more towards the top of the runner to try and negate some of the flow disruption caused by the butterfly valve.



2 counter rotating rollers with a bite out of each, when rotated to WFO formed a smooth bore opening. It did not have the huge inrush at low throttle angles because the hole started small and opened up as opposed to the butterfly which opens most of the way around the diameter. Many drivers did not like it because it did not have the snappy feel the large inrush causes (even though the dyno proved it made more power) it did not feel more powerful, but on a dry slick track with the slowed response it is much easier to keep the tires under you. A lot better than pulling off a couple of plug wires to soften the motor or backing off the timing.

Dr Frankenstien made slide valves for his motors and wanted to make a intake sliding lengthwise to alter the resonance of the intake.
Then I pointed out that by WHERE you squirted the fuel in could change the weight of the air which effectively changed the resonance (made the intake look shorter)

And he came up with this



You can see there are 4 injectors in a standard location on the motor side of the air valve.
Then he added the stainless line coming off the barrel valve feeding the 4 hoses which feed 4 injectors mounted on the air filter base plate that had J shaped tubes that sprayed fuel into the top of the runner. The brass cylinder between the stainless line and the hoses is a spring loaded check valve that stops fuel flow at lower RPM's, so by shimming or changing the spring you could adjust when the upper nozzles started spraying.

Then USAC got wind of what we were doing and blocked us in the 2010 USAC WEST COAST 360 SPRINT CAR ENGINE RULES

"E. Electronic or timed fuel injection will not be allowed. Only one injector nozzle per cylinder. No down Nozzle Injectors. No injection nozzles drilled directly into head. No computerized injection. Injection throttle body must have one shaft operated round butterfly per cylinder. Slide or barrel injectors will be not allowed."

Frustrating and gratifying at the same time, you know you are making inroads when they start changing rules around what you are doing. Yet it stifles innovation, that is why I like the Midgets, but that is not necessarily a free for all either.

At the Chili Bowl there is no tire rule. Cory Cruiseman came to the race with this. (I think he may have won with it)



So we took that a step farther and put a 15" wheel on the RR of a Midget, they spotted it and told us to take it off, since we were not a politically influential team that Bondio is, we had to comply.

Doesn't a single large throttle have the same low angle inrush issues?

Or are you now saying that you shouldn't even use that, but a butterfly valve?

Barrel throttles, like above on the midget, are generally worse than ITBs when looking at throttle position increase vs air flow increase.
They work great at WOT and allow you to run a very optimized runner and port setup if you have the time and technology to do the research and testing.
On the old FSAE car we went from a barrel to a small butterfly with no cross shaft and a profiled butterfly plate to reduce flow disruptions at WOT. Much easier to drive and tune.

The Jenvey Heritage throttle bodies are expensive, but you are getting them with injectors and wiring harnesses. So supply fuel pressure and a pulse, and they work.
If you want a classic looking engine bay, they're a great alternative to the "character" that carburetors offer.

Dirty Rick said:

Topic drift...

ITB's only work well at rpms well above anything used on the street. You need torque to get it moving.
blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah, blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah.
blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah
In the end this leaves ITB's as nothing more than a masterbatory aid.

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Utter and complete uunbelieveable Bulls**t

Where do people make up s**t like this...????

This guy needs to say his name, age, years building what and show some samples of his builds---and stop writing not slighty wrong stuff but unbelievably stupid things.