Description
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ACCEL’s Adjustable Vacuum Advance boosts power and delivers instant throttle response points-type distributors. It provides maximum spark with no harmful pinging or detonation, and both the rate and the amount of advance are infinitely adjustable. It’s almost effortless to install, is backed by a limited one-year warranty, and comes with detailed, easy-to-follow instructions and the Allen wrench you need to make adjustments.
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Customer feedback
Ratings and written reviews
4.0 / 5
20 source ratings
Source: Amazon. Imported marketplace feedback is shown for product research and is not a review of a purchase made on this website.
Vern Kelly –
My previous Crane adjustable vacuum advance failed (bad diaphragm) and I replaced it with the Accel 31034. I had to remove the distributer to install it to access both mounting screws. I like how Accel shows a graph in the instructions based on RPM, number of turns clockwise, and vacuum to show the relative performance settings of vacuum advance. I could not find this information on the Crane model. Also on the crane model I had to detune it quite extreme to eliminate the “ping”. The Crane had a limiting adjustment that I did not install as it changed the base timing. This may have helped but seemed like a real pain if you want to adjust it as the distributer would have to be removed each time. So far on the Accel I have detuned only one turn counterclockwise from the way it was shipped. I believe they ship at 4 turns clockwise, though I did not test for this. Drivability is excellent and better than the Crane model. I believe my mileage may improve a little as well. Crane model only lasted 7 years and about 30,000 miles in my 1966 Chevy C10 daily driver with 350 V8 before the diaphragm went bad. You can check this by sucking on the vacuum hose that feeds the advance mechanism and observe the breakerplate moving with the cap off. I use the ported vacuum off a Holley Carb.Well, November 23rd 2011, The Accel 31034 failed. Only lasted 1 year and 4000 miles. Worked great before it failed. Maybe this one was on the shelf too long. Truck felt sluggish. Tested by diconnecting the hose from the carb and no vacuum or movement of the breaker plate. Since I did like the performance I ordered another one from oreilly and will try it again.Still working on both my cars November 2020 after ~30,000 miles.Still working on both Chevys November 2021. Love how you can tune the centrifugal advance to your liking and finish off with the vacuum advance tuning for good street manners and cruising performance. Turn counter clockwise to decrease timing and clockwise to increase timing. Turn a half turn at a time and test drive. Tune hot engine with light throttle uphill on hot day to just eliminate ping. I use the ported vacuum advance off my holley carb to the accel vacuum advance.
JW –
The provided allen wrench did not fit in the adjustment mechanism a the start. I had to use a wrench with a rounded end, and even then it was tough to get started. Once I had worked the mechanism a bit the provided wrench would fit. Not a good way to start, especially if the unit was on a vehicle and difficult to reach. Otherwise, the canister seems to be working. The directions are good, but they suggest there is a positive stop at the counterclockwise end of adjustment when there is not: the adjustment screw starts to click instead. That clicking, I believe, is normal. I have a Crane Cams 99601-1 for comparison. The crane one has no adjustment issues, and based on the two I have seen, I would recommend the Crane.
Virginia Eades –
This vacuum advance is supposed to be adjustable. It adjusted once and then the the internal adjustment mechanism failed and the allen wrench would no longer adjust the settings. I WOULD NOT RECOMMEND THIS PRODUCT.
R.L. –
Failed before I even got a chance to install it. I wanted to believe it would work for me, but it failed just like the two reviews which explained the allen wrench screw failed for them, the one I received stripped even when being VERY careful! Great idea, but would NOT recommend this product!
Customer –
A+ All The Way !!!!!!!!!!
Placeholder –
I received this item as expected. It works perfectly
Your mom’s here –
I decided to power tune my 60s muscle car and this is exactly what I needed. After doing a few necessary modifications I installed this in around 45 minutes on my car. What a difference is made does engine is night and day from what it used to be now. I highly recommend this to anybody looking to add Performance to the old points, distributor style muscle car engine.
Earthboy57 –
I’ve been used to changing over to an adjustable vacuum advance. This one works well with my distributor. The part No. is a GM-10 at the auto parts store. No issues.
james earle –
5 stars, thank you