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88v8
Ivor Duarte
Gloucestershire UK
(1042 posts)

Registered:
02/11/2010 04:29AM

Main British Car:
1974 Land Rover Lightweight V8

Performer / AVS2 4bbl, tune compared.
Posted by: 88v8
Date: August 05, 2023 05:11AM

Removing the 500 cfm Performer from my 215 Rover V8 because of ethanol crap, and replacing it with a 500 cfm AVS2.

In this thread I recorded the Performer tuning setup, and I assumed I would just be able to swap the tune into the AVS, but nooooo.

The out-of-box of the Performer is 086 primaries with 65/52 rods, but the AVS has 095 jets with 70/52 rods, which is 30% richer on cruise and 35% richer on power. Presumably there's a reason for that, so I shall have to get out the AFR meter and start again.

Also, I'm not sure that I can swap the accelerator jets... are they a different design... Edelbrock's website has me tearing my hair.... it's pouring with rain atm so I'll go down to the garage and check later.

And the AVS has an autochoke, I never ran an autochoke, we'll see how that goes.

Anyone done the Performer / AVS2 swap?

Ivor



Edited 1 time(s). Last edit at 08/05/2023 05:19AM by 88v8.


MGBV8
Carl Floyd
Kingsport, TN
(4514 posts)

Registered:
10/23/2007 11:32PM

Main British Car:
1979 MGB Buick 215

authors avatar
Re: Performer / AVS2 4bbl, tune compared.
Posted by: MGBV8
Date: August 06, 2023 01:24PM

No. Been using my Carter/Edelbrock 500 for 22 years now. Often with E10. No issues.

Out of the box jetting is for an assumed larger engine.


88v8
Ivor Duarte
Gloucestershire UK
(1042 posts)

Registered:
02/11/2010 04:29AM

Main British Car:
1974 Land Rover Lightweight V8

Re: Performer / AVS2 4bbl, tune compared.
Posted by: 88v8
Date: August 08, 2023 04:40AM

I asked Tech Support why the fatter jetting, the reply was it's related to the annular booster... which makes no sense.

So yesterday I put the carb on the engine, created the wiring for the autochoke where I used a relay given it can apparently spike at 10A, and I swapped in the tune from the Performer with the exception of some fatter rods because I'm being cautious and I can easily swap in the current rods at the roadside if my AFR meter gives me the OK.

Unfortunately it's raining (again) all day today so I will have to wait until tomorrow to start it up, given the car is 'garaged' outside.

I presume despite the autochoke I still need to prime it with a couple of squirts?

Ivor



Edited 1 time(s). Last edit at 08/08/2023 04:41AM by 88v8.


MGBV8
Carl Floyd
Kingsport, TN
(4514 posts)

Registered:
10/23/2007 11:32PM

Main British Car:
1979 MGB Buick 215

authors avatar
Re: Performer / AVS2 4bbl, tune compared.
Posted by: MGBV8
Date: August 08, 2023 09:13AM

Try it without first. Didn't want the manual choke version?

I have never had a choke on mine. I just turn on the key, listen to the Carter fuel pump for 7-8 second, pump the gas 3 times to the floor, then start the engine with my foot off the gas.


88v8
Ivor Duarte
Gloucestershire UK
(1042 posts)

Registered:
02/11/2010 04:29AM

Main British Car:
1974 Land Rover Lightweight V8

Re: Performer / AVS2 4bbl, tune compared.
Posted by: 88v8
Date: August 09, 2023 01:04PM

The manual choke on my Performer started up OK, but then I had to juggle it two minutes or more in the winter, before I can drop into Drive.
I didn't particularly want an autochoke, but on eBay up pops this 500cfm AVS2, low mileage the chap said, and it happened to have an autochoke, and it was $$ below retail, so.... now I have an autochoke.

Two pushes on the throttle, it started right up. Set the fast idle. I could drive it straight away, no juggling, which is nice.

Out with the AFR meter to see what's what.
Can I simply transfer the tune that was in the Performer....?

Well, the 7057 rods I had in the Performer gave around 16/17, too lean, so the answer is No.

Tried 7042, 6852, then 6755 which run at around 14/15 and 11/12 at WoT so that's fine.

In my OP, I was talking nonsense about the squirters, I misunderstood the annular thing, the squirter nozzles are the same as the Performer so I transferred the 024s, rod in the bottom hole. No bog off idle, if anything it's fat.

So that's it:
083/080 jets
6755 rods
Orange springs perhaps
024 nozzles.

I haven't adjusted the secondary air valve as there's no spike going into WoT.

I just need to look at the transition springs, I see a cruise/power spike on the meter, may go back to that tomorrow.

Ivor


MGBV8
Carl Floyd
Kingsport, TN
(4514 posts)

Registered:
10/23/2007 11:32PM

Main British Car:
1979 MGB Buick 215

authors avatar
Re: Performer / AVS2 4bbl, tune compared.
Posted by: MGBV8
Date: August 09, 2023 02:23PM



88v8
Ivor Duarte
Gloucestershire UK
(1042 posts)

Registered:
02/11/2010 04:29AM

Main British Car:
1974 Land Rover Lightweight V8

Re: Performer / AVS2 4bbl, tune compared.
Posted by: 88v8
Date: August 21, 2023 08:04AM

Yes, an interesting Motortrend article there or is it an infomercial, anyway I agree the throttle response is really sharp compared to the Performer..
Not that one notices too much when driving with an auto but still....

Ivor



MGBV8
Carl Floyd
Kingsport, TN
(4514 posts)

Registered:
10/23/2007 11:32PM

Main British Car:
1979 MGB Buick 215

authors avatar
Re: Performer / AVS2 4bbl, tune compared.
Posted by: MGBV8
Date: August 21, 2023 10:23AM

How much vacuum at idle, Ivor? Those orange springs tend to be a bit weak for an engine with a lot of vacuum.


88v8
Ivor Duarte
Gloucestershire UK
(1042 posts)

Registered:
02/11/2010 04:29AM

Main British Car:
1974 Land Rover Lightweight V8

Re: Performer / AVS2 4bbl, tune compared.
Posted by: 88v8
Date: August 24, 2023 04:34AM

13 inch on the manifold port.
270 cam, never made much vac.


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