Site Search

Tiger Tracks Archive Search

banner-red.jpg

 

Dynomometer at Tracy ShopThe timing cover and oil pan were on. Next up, harmonic balancer, cylinder heads, pushrods, rockers and intake manifold. As mentioned in the previous article, we had started to experience fit and clearance challenges wherever the newly purchased aftermarket parts interfaced with the OEM parts.

This would be true as well for the balancer and the original stock timing cover. The high performance Powerforce Plus balancer is almost double the thickness of the stock balancer, and as we tightened it onto the crank it interfered with a couple of the bosses on the timing cover casting. Yuk! But upon looking closely, the part of the casting it was hitting served no vital purpose. So we pulled the balancer, took a die grinder to the timing cover, and notched it just enough to allow for clearance. 1964 part meets 2011 reality.

Now, would the stunningly beautiful AFR 165 heads pose any such fit issues with the old block and Edelbrock Performer RPM intake manifold? Answer: no. Using new ARP head bolts, the gleaming aluminum heads were easily installed over FelPro 1011-2 gaskets. Studs were briefly considered, but when I called AFR to double check on what fasteners to use, they strongly recommended bolts for under 11:1 compression. “For higher compression, you’d need studs, but when you don’t need them it’s better to go with bolts. They’re more reliable,” they said.

The intake manifold dropped in easily, a matching of aftermarket designs. An F4B would have been a nice OEM touch, but that manifold does not fit the AFR head design. For the water pump I had decided to go for an upgrade from stock, and get the Edelbrock high volume unit. This was not a pricey upgrade, and the hope is that it will give the motor as much chance as it can to run in normal operating range on a warm day. Fingers are crossed on that one.

But here again we ran into the need to modify a part, this time due to the unique-to-Tiger distance between the water pump flange and pump casting. The Tiger’s is more compressed (shorter) in order to allow for fan clearance. Making this Edelbrock part acceptable to the Tiger meant pulling the flange off the pump and grinding down the back of the flange so that it could fit closer to the pump casting. Then, using a stock Tiger pump as a guide, we pressed the flange back onto the pump shaft to the appropriate position. Pulling the flange off was made easier by a special Ken Matisse handmade puller that I borrowed from Bill Martin, but still…All of this effort for a little extra water circulation? I wondered: Was I overdoing this a bit? Was this worth the effort?

Well, I will say this: Though I don’t know how it will do in the car yet, the strength of that pump wound up being quite impressive on dyno day. At over 4,000 rpm it pulled so hard that it collapsed the inbound hose down to an oval shape. The sight of contorting hoses mixed with peak rpm engine scream gives true meaning to the words “It’s Alive!”…a visual I will not soon forget. Note to self: When it goes into the car, get a reinforcing wire coil in that hose to prevent any circulation problems.

With the water pump modified and fitted we were ready for a carburetor and distributor. The Pertronix distributor, coil and wires were easily installed. The carb was a modified 600 cfm mechanical secondary Holley coming from Don Gardyne, but as of final assembly it was not quite ready yet. So we borrowed a test carb that would be used to run the engine prior to the dyno testing.

I had decided at the onset of the project that I wanted to borrow or rent an engine test stand to run the engine a bit before taking it to the dyno. Even though lifter and camshaft break-in is not a requirement for roller motors, (as it is with flat-tappet), having some run time would allow us to make sure nothing leaked, and do any trouble-shooting work on valve adjustment and ignition timing. I found out that Terry Taylor owns a test stand, and he very generously offered to loan it to the cause. This turned out to be a good decision, as by the time dyno day arrived the motor was ready for immediate testing and tuning.

With the engine in the stand and borrowed carb installed, we started the motor using only headers and a pair of straight flow-thru Glass Pak mufflers. It was a good thing we pointed the exhaust outside. After about three minutes of running, no windows in the adjacent apartment building had been blown out, and no police had arrived… but all the birds had left. We shut it off.

The quick throttle response provided by the aluminum flywheel, the breathing of the AFR heads, countered by the tightness of the rings, all contributed to the impression of a wild beast trying to bust loose from restraints.

We double checked valve clearances and found a few that needed adjustment. We double checked our ignition timing: 10 degrees at the crank, plus 22 in the distributor for a total of 32… should be about right. We re-fired the motor and ran it until a heat gun pointed at the thermostat cover indicated 170 degrees; pretty much operating temperature. It wouldn’t idle below about 1800. It was too tight still, and the carb wasn’t set up with enough mixture volume.

I called Don Gardyne. The carb was in final assembly and would be ready the next day. I called Gerard Raney at Cal Dyno in San Carlos, and booked Saturday August 20th.

After a third test run the motor had about 20 minutes of run time. It had settled down and idled with the borrowed carb, which allowed for accurate ignition timing adjustment. Oil pressure and water temp were fine. It sounded very strong. It didn’t leak anything. We were ready for the dyno.

Building a 5 Bolt “Roller” Continued: Dyno Day

It was time to see what the beast would do. After months of design decisions, parts buying, machine shop work, and assembly, it was finally time to test the combination “dynamically”, and see what an engine dynamometer would measure as it’s output.

When I had called Gerard Raney at Cal Dyno and booked August 20th, I suggested we might only need half a day, owing to the fact that we already had 20 minutes on the motor on a run stand. He sounded skeptical and explained: “I block out an entire day for a test. Things take time, and you don’t want to rush it.” Don Gardyne agreed to meet us there with the Holley he had been building for me. (See sidebar article “The carburetor”). Part of the deal in working with Don is that if the tuning or dyno work is done locally, (he lives on the SF Peninsula) he is available for house calls, and will dial in the carb as part of the service.

Tim and I arrived at Cal Dyno at 10:00 a.m., Don about an hour later. Gerard’s shop and dyno room is very well equipped. Hooking up fuel and water supply, exhaust, ignition system, did not take long. Don checked float levels and they were perfect. By 11:30 the engine was fully installed and ready to fire. Don had jetted the carb with 70 in the primaries and 77 in the secondaries. We would be running with 91 octane pump gas, with no octane booster, and starting with 35 total degrees of advance.

Speculation abounded on what it would produce, but most estimates put it at around 350 h.p. and 315 to 320 ft. lbs. of torque. But the time for speculation was over.

The motor started readily, and Gerard ran it through some varying rpm’s under a light load, rolling it up to about 3100 and down to 1500. A check of all pressure and temp gauges showed everything was warming and functioning well. After about 10 minutes Gerard suggested a modest pull from 2500 to 4000, just to make sure things were all “finding a home and getting to know each other in there”.

He ran the motor up to about 3000, introduced load, and then opened the throttle. The motor almost immediately raced to 4000 and automatically throttled down. The results came back instantly: 265.7 h.p., 349.5 ft lbs of torque.

After a quick adjustment to the dyno to make sure it was applying correct resistance, we were ready for a back-up pull; a confirming repeat of the same rpm range.  And, the same results came back. Still no leaking, and running great with the new carb. We upped the ante to 4,500. This produced 298 h.p., 350.6 ft lbs. The torque performance was huge; much bigger than I expected. The horsepower was still well below target, but we had 1,500 more rpm to go. 

We went to 5,000, and got 327 h.p. and 355 torque. Then on to 5,500, and the power jumped to 346, with the torque staying at 355. We had reached the mid-300 power neighborhood.

What followed was six straight pulls to 6,000. The only adjustments we made along the way were ignition timing, and a few pulls without the air cleaner to see if it made a significant difference. To the credit of the K&N Extreme, removing it did not make much difference at all.

The final pull produced 362.7 horsepower, and 354.8 torque. It was a few minutes after 2:00 pm, and the performance aspect of the dyno test was complete. The power output was almost exactly what I had hoped for. What had exceeded my expectations was the torque. My poor tires were not going to stand a chance. Oh well. I’ll just have to deal with that problem later!

Gerard restarted the motor and Don entered the test room to set about mixture and idle settings. With that much duration and lift, it is not unusual to have to run the idle higher than you would normally like… over 1100 in some cases. But the low resistance provided by the roller technology makes up for this, and we had the motor idling comfortably at 850. This was another great by-product of reducing inherent internal friction as much as possible. Don set it up at 925, and we called it good and shut the motor down.

There were smiles all the way around. It had been a great day, with great results. Now I just have to put it in the car, and figure out what I’m going to do for traction.