Thanks @BQUICK I wasn't surprised other than it was only one lobe. @sean Buick 76 its a flat tappet. Question for everyone, should I take this opportunity to go roller or just stick with the 284-88H
When using a roller cam you need to secure it in the block at the front so it doesn’t push forward. There are several ways to do this and at first a few people didn’t get it right. I personally go against the popular belief on roller cams for these engines. I see a bunch of downsides and I prefer a flat tappet for all mild combos. 1. cost 2. There have been a lot of roller lifter failures 3. Yes roller cams can be more aggressive without compromising street ability, however most combos don’t need a giant cam anyway 4. Weight of the lifters is much higher 5. Valve spring pressures are way higher When really pushing the limits of the cam specs that’s when the roller cam shines. Less loss of low rpm torque while still maximizing high rpm potential.
Another factor is that almost all engine builders would prefer to use a roller cam so that there is less chance of a cam issue during break in. However that’s not normally an issue if we follow the break in procedures. Anything a builder can do to reduce the chances of an engine issue is HUGE for them. For us building them ourselves it’s far less of a concern in my opinion.
I agree, I suspected that I was going to have an issue. You can't crank on a new cam even in short burst and not expect an issue. Good thing about the 284-88H is that I have the lifters set side and numbered in their original positions. Should mean no need to break in.
This is an engine of many surprises. What I assumed was a lobe that had been wiped turned out to be a lifter that wouldn't pump up. New lifter and she's running
Well I can only say how pleased I am with the Progression Ignition distributor. Idle is as solid as I've seen and way better than I expected. Being able to tune the ignition map makes coming off idle no problem. Looking forward to getting this on the dyno next month.
Hi All Its been some time since I updated you on the 455 in a Land Rover. Well things have not workout as I hoped. The last time I was here I had installed the new cam etc and it was running nicely on the stand, freely reving to 6000rpm. So before Christmas I booked a dyno session. The intial run was to 5900 rpm and gave a solid 500bhp. The second run stopped at 4200rpm when something definitely came adrift. The end result was a forged rod putting a large hole in the sump and the starter motor launching itself across the room. I've spent many hours disecting the wreckage and my best assessment is that the cam snapped. So I'm not looking to autopsy this here, it is what it is, but it does mean I now have some nice 455 parts that someone may find useful. Over the next week or so I'll be listing them in the 'For Sale' section. I doubt it's economic to post them back to the USA but someone in the EU or Ozz may be interested. As a warm up here's a list of what I have: TA Performance Street Eliminator heads with bowl work. TA Performance Roller Rockers 1.6 ratio. AED 850 HO carb. TA Performance Rocker Covers in black with highlighted lettering. TA1325B I think. TA Performance SP1 intake. TA Performance Timing Cover TA1531B. TA Performance Oil Pump Cover TA1512F. Meziere Electric Water Pump. TA Performance HEI Distributor TA691. Progressive Ignition mappable distributor. There are a few other bits but off the top of my head I cant remember them all. Everything has been thoroughly checked and I'll supply as many photos as people want. Everything has about 4 hours of dyno time plus a few hours due to me just wanting to listen to it run
Oh boy, so sad! I was following your thread with all the ups and downs you experienced. Are you sure you want to quit now. I would sleep over it and not make a quick decision you might regret one day. However, if you call it quit I will be interested in the Roller Rockers. Shipping to Germany should not be too bad. Ralf
Hi Shurkey. The rods were custom made by a reputable manufacturer. I must reiterate that it was not the rod that failed, it was just a casualty of the carnage.
It's unlikely that the cam "snapped"...unless it was beaten by a flailing connecting rod that broke first.
I'd agree. For something with no real stress on it, compared to a rod or piston, I can't believe the cam broke. How would a broken cam lunch a rod? Every time I've seen a broken cam, it was caused by rod failure which is usually the result of oiling failure.
