I've just returned from 5 days In California, on a quest for more HP in the flathead- wow, did I ever get my arse kicked! More on that later!
Tuesday morning, I met Rex Schimmer for breakfast, then we headed over to Dema Elgins, and spoke with him about a cam. Rex, thanks for taking the time to meet with me-it was good to see you again! Tony, time was short, but we'll catch up next time, okay?
From Dema's I headed down to Rich Fox's, to pick up a tranny he loaned me. Always good to see you Rich!
Then, on to Don's place, where I picked up the test chambers he cut, so that I could modify them, instead of our real heads. Don's always on top of this stuff!
Tuesday night I was in Arroyo Grande , having supper with Garry Odbert. Garry was an immense help on everything- he even had his test block there, so we could compare the porting to his. Garry runs the Retarded Spark Special, a record setting Caddy flathead powered roadster. Thanks Garry!
Wednesday morning, Garry and I headed over to Race Engine systems, in Santa Maria, owned by Craig Gerfen. Craig was Alan Johnson's top fuel port and flow guy for 8 years, and had also ported Garry's Caddy flathead.
Here is where the arse kicking started! I'm not going to post every number, test, and dye test we did, but I'll tell you what we found out. Plain and simply put, the ports are too large, therefore velocity suffers, and they don't flow as well as they could. Across the board, we're down about 20 CFM from Garry's. We flowed my engine, then Garry's, back to mine, etc', so the data was current and reliable.
After, trying everything to increase flow- different valve angles, different valves, different chamber designs, blending the valve guides, etc., to no avail, we tried a different approach. We added material around the short side radius. BAM- an instant 10 CFM gain! We played with this for a while, and determined we need to add material back to the ports, then do another port job. We also played with the relieved block, but that only reinforced my previous belief, and that belief is that it is a waste of time.
So, I called Frank Morris with the Salt Cat guys, to find out what epoxy they had used on the Buick engine. Frank and Doug are great guys! Frank gave me the info I needed, sold me a set of 29" tires, so it was a win/win conversation for me! Thank's Frank!
So, it can't get any worse, right? Wrong! We flowed the exhaust, and they sure do flow- too Dodge much! The exhaust out flow the intakes, and that is not good! That correction will come with the cam choice- my guess is we'll end up with a dual pattern cam.
We did a couple of dye tests, to see what was going on in the chambers. With our current setup, the A/F mixture swirls around in the chamber, running back into itself- basically creates a traffic jam in the chamber. We took the angled ramp out, and straightened that transfer area out. On my engine, we see a small inrease on flow, but a lot better flow pattern out of the dye.
At the end of the day, the stock block, ported, with a stock 106 CC Caddy head, flows better than the FlatCad head and either of the 2 mods I made, better than Edmunds, and better than Cyclone! The stock head has several complex contours and ramps in it, and flows well- it appears the Caddy engineers really knew their stuff!
So, to gain the CFM I went to California for, we need to add material to the ports, re-port the block, and change our chamber design. Here are numbers from the #8 cylinder, which is the best flowing cylinder on Garry's car- he flows 200 CFM on the intake side. Our best cylinder was # 3
#8 intake #3 intake #8 exhaust
.100 lift 69 64 73
.200 121 118 120
.300 154 157 145
.400 175 173 165
.500 173 180 174
.525 173 179 176
Here is what is typicle of our worst ports, intake only
#5 intake #5 intake modified with clay
.100 lift 63 60
.200 114 110
.300 150 151
.400 162 169
.500 163 174
.525 163 174
At this point, I had the knowledge I had came for, and I loaded up and headed back to Don's place to spend the night. After a nice dinner, Don and I retired to the garage, to smoke, joke, and bench race. Don, as usual, it was great seeing you and Dar- many thanks!
Friday I headed for the house, but stopped in Salt Lake City to visit Kenny Kloth, as I had some specific questions for him about roller lifters and his chamber design. Kenny is a great guy, and a wealth of knowledge, He was very helpful, and informative. I stayed a couple of hours, but easily could have stayed several days, had time permitted.
So, the HP quest continues!