davidmlbrown

I am having difficulty removing the prop flange from a 52 cc engine. Can anyone tell me if the prop flange is a "slip-on", keyed or "screw-on"?

Truckracer

My Feedback: (19)

davidmlbrown

I could be mistaken, but the engine isnt readily available to check.

Truckracer

My Feedback: (19)

davidmlbrown

That is what I suspected. I plan to put it in the freezer for a few hours, then use a heat gun on the flange (aluminum). Thank you.

davidmlbrown

Yes, it is a Brison 3.2 CI which Brison indicates is a 52.2. CC. We are having problems with the ignition module, so my son purchased a new module and pickup. We need to remove the flange so the case can be cleaned up, then install the new pickup. Thank you again for your help.

CK1

My Feedback: (60)

The prop flange is a tapered fit with a bronze compression sleeve between the crank and the prop flange and may also possible have some assembly loctite applied . Use a press plate behind the prop flange and support the flange in a vice or other suitable device . Apply heat to the prop flange to expand it then tap down on the crankshaft (protect the crank threads )using a heavy brass mallet. The prop flange will pop loose

davidmlbrown

Thank you. The crank shaft is still in the crank case. In this configuration there is "minimal" clearance between the flang and crankcase. Are you suggesting that the propshaft can be slipped out the front of the crankcase? I assumed that the bearing and crank would prevent that. Thank you again for your help.

CK1

My Feedback: (60)

No the crank does not need to be removed . Press plates have tapered edges that allow them to get in behind the prop flange . If you are unfamiliar with this tool it might be best to take it to a small engine shop .

Truckracer

My Feedback: (19)

Hmmm, every Brison I have disassembled had a straight wall bore in the hub with a keyway. Not saying Gary didn't build some with split collets, I just never saw one. I have attached a couple of photos of the small, more recent hub. They used different sized hubs over the years with early ones being quite large. The smaller hubs had the magnet on the outside diameter of the hub in a more normal manor. The larger hubs had the magnet installed on the back side of the hub and the sensor was installed behind the hub. All installed in the same manor on the crankshaft though.

Regardless of whether the hub is straight wall bored or taper bored for a collet, the hub would still be removed and reinstalled in the same manor. The small hub can be a pain to remove though as there is little or no room for tooling to support the hub to press it out. I usually just press out the whole crank as an assembly .... through the hub and bearings.

Note: Sorry for the huge photos. Not sure why they uploaded so large.

CK1

My Feedback: (60)

Yeah Gary used both designs it seems .The one you posted ususlly give no trouble to remove . The ones using the split collet are the trouble makers but the process is still the same for either one .

davidmlbrown

This engine has the smaller flange and, as you say, there really isn't much to grab a hold of with a puller. I will keep you posted. Thank you for your help.

Truckracer

My Feedback: (19)

Gary was noted for changing things up a bit between production runs. I still like the engines though! Just curious, how did he maintain the hub in one location for timing with the split collet? I know that using a taper bore hub on a tapererd crank was common on many other engines, but the use of a collet was rare on gas engines, common on glo. Once a hub is seated on a tapered crank, it pretty much stays in place but a collet is prone to more a bit unless a lot of loctite was used.

davidmlbrown

I've not had any experience with these engines. Have you been satisfied with their performance? My son and I are just sport flyers, i.e. flounder around the sky and hope to take the same plane home that we brought to the field. Thank you.

Truckracer

My Feedback: (19)

These were very good and powerful engines in their day and remain so today. As long as they are in good condition they will continue to run with the best of them well into the future. These engines used the very popular Sachs pistons and cylinders that were noted for being very high quality. Sadly, some of these parts are getting a bit hard to find these days as they are no longer produced.

The piston ported intake design (carb on side of cylinder) has sort of fallen out of favor in recent years as the reed valve, rear carb engines have become more popular. Both engine designs have their pros and cons and some fit certain applications better than others. As a loose rule, for a given size engine, the piston ported engine will tend to favor a bit less prop load than the reed valve engine as they like to rev to produce power. A reed valve engine may excel at producing torque at lower RPM.

Enjoy the engine!

CK1

My Feedback: (60)

Some of Garry's cranks are not tapered but straight , still keyed though . The tapered collet would go on the crank first then the key then the tapered keyed hub or prop flange as it may be called. This design I have found mostly on the blue cased engines 3.2 and 6.4 twin . Now that I think about it I think there also a version where the collet is also keyed where the key goes in first then the collet slides over then the hub goes on . One of the versions the key actually protrudes from the face of the hub by about .020 ".
All of Garry Allisons (Brison) engines are excellent engines by all standards . The power to weight is very good , not the best but still very good . The quality is vastly superior to even DA or 3w . You will never , literally never wear one out . You may break it in a hard crash or damage it from no oil in the mix but I have never seen one wear out from even the highest level of usage .

davidmlbrown

Thank you both. This engine looks like it is has been run very little. It looks new, really. It came to us with a problem with the ignition module, so that is where we are now. New module and pick-up sensor.
Thank you again.
Dave

CK1

My Feedback: (60)

Was it a Cimmaster or C&H ignition that failed ?

davidmlbrown

It wasn't a C&H Ignition module. If those were the only two OEM installed, then it must have been the Cimmaster. My son ordered a new module and sensor from HK. So, that is where we are at, right now.

CK1

My Feedback: (60)

Garry used C&H exclusively when he ran things . When Garry got out of the company and production moved to Canada Cimmaster ignitions were used and were prone to failure . The engines themselves remained essentially the same .

davidmlbrown

That is good to know. Thank you. I am familiar with C&H products. I am converting a ST3000 to ignition/gas now. I am getting the feeling that if and when the Brison engine fails, replacement parts are not likely available. Is that true? I've not found a parts breakdown or source. I've tried to communicate with the distributor, via email, and not received any responses.

Truckracer

My Feedback: (19)

Every Brison crank I have seen was straight (no taper). Strange that I have not run into one of the engines that used a tapered collet. For awhile a few years back, I bought and resold a few Brison 2.4 and 3.2 engines including some of the colored case versions. Some required bearing replacement, especially the cupped needle bearings in the rod. Most times if the crank bearings were bad it was because the seals had blown out. Sometimes the bearings themselves would be good but the integral seals were completely shot and flopping around loose in the case. Pistons and cylinders were usually just a clean and reinstall deal and sometimes a ring. Darn good engines though! I still have (3) Brison 2.4 that were made over a period of years ..... a very old one and progressing to one of the last ones Gary made.

davidmlbrown

This engine is anodized blue. It really looks quite nice. I don't believe that it is likely to be worked very hard. So, it should last my son a long time. Thank you

Truckracer

My Feedback: (19)

Brison parts are available, you just have to do some looking to find them and know what you are looking for. The Sachs, Dolmer, Makita parts were widely used in a number of different chainsaws and that is the primary source of parts these days. There is quite a network on chainsaw collectors and restorers out there and they know where the parts are. Prices get a bit steep though for the prime parts. Parts like bearings are common and readily available from many sources, The only part that can be a challenge to source is the Brison specific crankshaft and these can be unobtainable!

Good luck with the ST conversion. I saw a few of those conversions some years back and they ran OK, not great. Then tended to be a bit of a shaker though they run smoother on gas than they did on glo.

CK1

My Feedback: (60)

I would say you probably have had them but the keyed collet version where the collet can stay in the hub when you have pressed the crank out . If you didn't look closely into the hub you wouldn't notice it was in there