200 CFM Research

[106-1194218389]

Thanks John,
and so would a "D" shaped piston dish with some quench be the way to go?

[jsa]

[200cfm]

Almost September and I haven't gotten started on a new race motor yet. But I put together a mock up using a spare short block I had in the corner. What started as a mock up for a twin turbo fabrication turned into a complete install and test this past Friday to see if it would spool up. Still has some issues especially with the low rpm but once it got above 3800 it went down range surprising fast. Set a new mph record for the car in both the 1/8 and 1/4. Launch boost was weak with mere 3 lbs but it hit 10, then max of 14 for the rest of the ride. Now if I can get it to launch like the single Rajay.

Run 1: 1.878 5.276 8.045 @ 89 10.426 12.442 @ 111.68

Most of this run was with a 3-4 lb start and 5 # most of the pull then a gradual move to 6-7 lbs. Reset the gating in the pits.

Run 2: 1.840 4.794 7.173 @ 103.47 9.224 10.983 @ 126.52

Left around 2-3 lbs but once it spooled it pulled to 13-14 lbs.
Pressure is about the same as the single Rajay was putting out but with dual exhaust now the T04's were netting more top end power. It has moved from a best of 123 to 126.5 mph. These were salvaged units and took pieces from 4 units to make two units. The compressor wheels though are not in the best of shape and had to juggle the center sections until I found two that would not smoke from the turbine.

I started the mock up with the idea of the Rajay feeding the T04 in series or tandem. But then figured the fueling would never support the pressure so gave up on that idea. So went parrallel with the T04's. Turbine A/R is .58 and compressor wheel is 1.825-1.830 by 2.750. They have wear cuts and I found out they should be 1.840 inducer. I thought they were S-3 trim but they are not a S-3 or a Y-4 or the E-1. My welding skills are limited and all the tubing came from my scrap pile of salvaged pipes. A cut an paste effort here.

The heads are from the lost rod motor with the small valves I posted about here. Still short of that 200 cfm goal. And the intake is the one I was hoping to test out when I broke the rod on the other motor after reworking and flowing the runner manifold pinch turns.

A friend sent me a LC-1 A/F meter-sensor and it reads below 11 for the runs, looks like 10.3 to 10.5. That's too rich, right?

I can host up a video if there is any interest.

[larrycavan]

I can't begin to tell you how much I admire what you're accomplishing. You're always making positive moves with discarded parts!......That is a true hot rodder if there ever was one!

Question - Why did you reverse the pipes at the carb where the two turbo feeds join?

Larry C



Edited By larrycavan on 1219801156

[200cfm]

Thanks. As I went through my garbage can of pipes and bends that was the only coupler that matched up with the tubing and old silicone hoses on hand. This is not a symetrical balanced system for the moment. Just wanted to test a layout design and see if it was functional. If I stay with twins I will clean up the balance later. It was tuff getting it installed and accesible to oil dipstick, spark plugs, valve cover removal, etc. And it has to all be removable without pulling the motor. That was the goal.

On Friday nite the A/F was down to 10.3 to 10.5 range on the runs using a LC-1 innovate. And around 11.5 to 12 on idle. Jetting at 73/87. Since then I pulled the power valve and blocked the port. Got it idling now at 14:1 so I suspect the PV was leaking fuel. Made a test stall yesterday and got better spooling with around 11:1 A/F. But don't know if it will be leaner on a race pull with no PV. Thinking of setting the jets equal on pri/sec but what valve is unknown. It's a Holley square bore 4010 so they should be equal if no PV I would think.

Also working on improving the wear and damage on the compressor side. Found a source for the impeller. It is an obsolete size but he had two in stock and got them both for $68. Size is 1.840 inducer by 2.750 exducer. That puts it smaller than an S-3 trim and much smaller than a V-1/2 trim. Seems to fall in between the Y-4 trim and S-3 trim. A S-3 trim is 1.904 by 2.750. Turbo book says a single V trim can support a 350 sbc and twin S-3 trim can support a 350 sbc. So at 298 cubes I may be in the zone of adequate lbs/min and hopefully an efficent part of the compressor map. Just don't have a map on my size wheel.

Got the new wheels in this week and have started on one unit.
If I had the time I would like to flow the whole system on the flow bench. From filter, through the pipes, over the turbo, and down the carb, manifold, head port. Bet that would show some interesting twists and turns for air improvement.

If I can get the twins to spool as fast on the line as the single Rajay it should pull a good 60 ft time and then offer more power on the top end.




Here is the impeller from the psg. side unit. The air was taking a beating from these blades.


One unit completed and ready.

[larrycavan]

Not to change the subject but I received and email from my Megasquirt supplier the other day. There was an old Stude that set a record at Bonneville with one of their FI setups on it. .....

[106-1194218389]

Like I have said I get excited to see you go fast! I know you are not high dollar but you have ingenuity and brains. I have seen some local racers here dump bushel baskets of $100 bills in their cars and not go as fast as you have. It would scare me if you had some strong financial backing. Can you imagine how fast you would go? Question is would you have as much fun? Keep up the great work. You inspire me as sometimes I get down a little because I do not have the money to put in my stuff like I used to. And don't get me wrong you have a great ride I would be proud to have. Your ride is what racing should be about.

John

[200cfm]

My wife and I took our first vacation in many years and spent a week in Lancaster, Pa. While there we visited Bruce and his wife. Got to see the new PTS flowbench in action and picked up a new PTS pitot tube. Bruce was a gracious host taking time to show us the shop, his massive lathe, mill machines, etc. And he reviewed one stude cylinder head I hauled up for analysis. I came back all fired up about the new PTS bench project and cylinder head flow research. Thanks Bruce for your hospitality and time.

[bruce]

Tom, Yes I enjoyed your visit! I'm glad I was able to show you around the "World Headquarters"!

I can always take the time for visitors



Edited By bruce on 1222216390

[200cfm]

Have cut up one good head for easier study and research. Delivered this chamber to a machinist for a valve enlargement and once I get it back I hope to improve the flow and speeds. Test valve will be a 1.900" valve with a back cut and 30/45/60 bowls. Will save the other chambers for a smaller valve study. I flowed it with the stock valves for a base reference and mapped the port speeds with the new PTS pitot.

[106-1194218389]

Tom,
You're scaring me. You are getting serious. I am going to have to "shelf" my SBC as I don't want to get beat by a Stude. I know you are going to get this thing to fly. It already impresses the heck out of me. Keep going. I love your story.

John

[106-1194218389]

I have been interested in the Engine Master's Challenge and have been trying to follow it. I found an excellent article by David Vizard and suggest you read this as it may help in developement of your engine. David Vizard's I know I will read it as I develope mine.

John

[200cfm]

That was a good read article, thanks. Sure wish I had a bigger bore. The stude 289 has a stroke of 3.625 on a 6.625 rod for a 1.827 rod/stroke ratio. The motor I hope to build up this winter will be a .060" over bore on stude 3 9/16 bore to make 3.625 bore for 299 cubes. Perfect square motor. The motor I lost was this dimensions. Not sure if the 1.900 valve will clear that bore at this point. I do know a 1.840 valve clears ok.

Currently trying to get a motor ready for fall season here if possible. It will have an .118" over bore for 3.680" using Ford 6 cylinder pistons and the stroke will be a welded up 3.625 to make 3.875". This nets 330 cubes with 1.710 rod/stroke ratio.
Looks like an under size combo.

Used the cut up head on the block to see how close the bigger valve cleared the wall. Here is photo. Valve is 1.940" and it cleared by ruffly .030" But didn't go with this size on the mock cut head cylinder. Went with 1.900 which will clear just fine on 3.680 and may or may not clear on 3.625 bore. Valve here was painted red to show photo better. Some red reflection got into the cylinder glaze.



Here is chamber with stock valves 1.655 / 1.520 Note those quench eyebrow pads and what look like swirl bumps in the chambers.

[106-1194218389]

Nice photos. You are bringing out "John, the Mad Machinist" in me again. I was known for doing weird stuff. I see you have replaceable valve guides. They look to be .500" od guides. Find some that are larger on the od and set your head up in a mill and offset bore the guide holes in the head to move the intake valve more to the center line of the cylinder. Then also install a smaller exhaust valve. You will have to install new seats in the exhaust when you do that though. With your combo I bet you could get away with a 1.45" exhaust valve. That way your could easily go to the 1.940" intake and get it away from the cylinder wall. Can it be done? Done it , been there. I have gone as far as putting a cast iro set of Buick 300 heads on a 215 Aluminum block Buick to get bigger valves and ports. Had the heads welded up with cast iron in a special process to raise the ports. Had to make our own head gaskets. Was in a sand racing jeep. It would just kill Small Block Chevys. Lots of work though.

John

[49-1183904562]

Tom,

Nice photos I would agree with John, Goodson sells a nice Bronze guide blank that might work. But based on your above post it looks like you get all your machine work done outside and this could get pricey as this must be done on a mill.

Rick