Accusump and chain tensioners
 

Just thinking as whether an accusump in addition to the obvious benefits would have another less obvious one.

Would it serve to pump up the tensioners before start up,
eliminating wear and noise due to chain lash?

Before you start the car.. open the valve on the Accusump. This is the way you are **supposed** to use the Accusump.

Before you close the valve.. rev the engine up and build oil pressure to refill the Accusump.

You'd be amazed at how many people don't know how to use their Accusump.

Been using them in race cars for 20+ years.



B

We like to use and electrically controlled solenoid valve on the Accusump, which will accomplish the same goal automatically when you use your ignition switch. Just removes one more variable…………

I stopped using the electric solenoids years ago. They open too slowly (you can see it in data) The Accusump is already slow to respond, adding an electric solenoid to the equation slows it down even more!!

and yes.. I have the latest solenoid/valve on my desk.. still too slow :(

I'm not convinced it helps save these M96.M97 engines. I have plenty of blown up engines that I know for a fact had Accusumps on them.

Where it helps? Banked ovals like CA. Speedway/Daytona/Homestead, places where the car is in the banking for extended periods of time.


B

Brad, the valve is wide open anytime the ignition is turned to the "run position”; so there is no lag involved because the valve is already wide open. The only thing the electrically controlled valve does is make the install a bit more user friendly, in the sense that if you make something simple, people will actually remember to use it.

When shutting the car down, just hold the revs up for a moment, and then switch the ignition off. The unit retains plenty of pressure for a pre-start lube; turn the key on for a 3 count, then start the car. On cars with pressure gauges, the results are obvious……….

For some reason, all the other installs I have seen using the electric valve have all been on switches.. I have no idea why.. I use manual. One less electrical part to fail. Remote pull lever. Add it to the list of driver routine.

I can see how the "key on" would work for street cars :)

Have never had one fail to date.........

To the OP - I think this is a great thought, and could help chain guide life, which seems to be an issue for some.

Actually there are two vesrions of the electric valve system. One is a standard solenoid that Canton warns is for start-up pre-oiling only. I don't know why, but I had guessed it must be a reduced port size valve.

The other electric valve option is supposed to charge the accusump slowly, but flow out at a higher rate. I can't imagine how / why this works.

So, I just ordered the manual valve one too, as I don't trust the solenoid operating scheme, and yes solenoids do fail. I got the big 22" long one, which fits very nicely in the tunnel above the water lines.

I think you may be misinterpreting their information; the EPC series only releases oil at the preset pressure ranges, it does not restrict the amount of oil released, only the pressure at which it is released.

Great discussion....I was just wondering if we think the volume and pressure is enough to get to the tensioners before start up such that one can hear the difference in chain noise with or without the accusump firing. Potentially a great reason for using it off track too.....yes I have a five chain motor

No, I understand that from Canton's literature, the EPC valve charges the accumulator slowly, and is supposed to discharge at full flow at a pre-set pressure (assuming it had sufficient time to re-charge with that slow fill thing going on). I just don't trust this compared to a full open line to the accumulator for charge / discharge.

I can't say, mine is now in shipment from Race Mart who another guy on these boards recommended. They absolutely have the best prices going on all Canton products.

I took the post semi off topic, so I'll answer your question :)

Yes. It would help eliminate the lifter clatter you hear at startup.

Question is: Why do you have noise?

I have a race car right now with noise. We will drive it til it blows!



B

jaykay, thinking out the box here......
If you are still concerned with your startup noise (as per your posts earlier this month) have you considered installing a dashboard "no start" switch to, for example, the fuel pump where the starter motor turns the engine for a few seconds to build up oil pressure but the engine does not fire. It would only take 4-5 seconds on the starter motor to to build up enough oil pressure to pump up the tensioners - then you could flip the switch to allow the engine to start as normal.
I don't know the ramifications with the Bosch ECU using this method, but surely it couldn't be that difficult.......
It may just work untill you can get the chain tensioner overhaul in place.

Yes agreed on race mart...checked it myself a while ago! Let me know how your installation goes.
I am trying to imagine how the slow fill would be an advantage. I dread trying to route a control cable for a handle, in street car. Maybe it is a way of keeping oil pressure up while filling the accumulator after an event.

Great idea.....I actually do this manually with the key after the car has been in storage. I engage the starter for two seconds and let it sit for 20. Then do it again and a third time. Probably very bad for my starter motor/solenoid but I am guessing that this process is giving me oil

I don't have the experience to know whether the clatter is more than normal but it is there. I am sure I need to pull the tensioners as recommended by the experts here.
Also just trying to find ways/routines to keep engine healthy!

sorry for the slight off-topic... but since we're on the subject of clatter at startup...

If I get clatter only if the car has not been driven for a week and if the car is driven daily, she fires up with no clatter at all. Is that normal or the tensioners are still on the way out ? Or most likely somewhere in between ?

I believe this is in part due to oil draining from the tensioners over time if we are considering chain clatter sound changes....engine experts?

Depending on charge pressure at shut down the accusump may be able to overcome dirty/ work tensioners allowing for quieter start ups.

Most people do not know how to properly shut down an engine with an accusump to "charge" it for the next start up. Any car that has an accusump (using the electronic solenoid) needs to have the engine revved to 4,500 RPM and held there for 1-2 seconds then shut the key off immediately NEVER allowing the engine to return to idle. This ensures a significant discharge of volume and pressure from the accusump at the next start cycle.

If concerned with start up and tensioners, just pull the tensioners and clean them, or replace them. Otherwise you are applying a band aid.

Hah! i agree fixing the tensioners is the solution, but 'just' = big $ no?