Don Terrill’s Speed-Talk

If you have a elongation and thermal expansion model that correctly predicts the piston-to-head clearance at overlap TDC and then you add the gas pressure to that model at combustion TDC, my guess is that you'll have a pretty good model of how high the squish clearance actually is at compression TD...

Volvo Touring Cars 242T's were pretty dependant on Toluene mixed with LL Avgas in the mid 80's. Seems to be it was modern that time using that quite toxic octane adder. The 240T I don't know very well, the ETCC wasn't well known here. More popular were here the STW, DTM and BTCC were also Volvo par...

Thanks Lotus for an other very informative post. I guess this statement from Larry sums it up really: You are welcome. The interesting thing starts with another paper in mind by Shinh E. et al., The role of intermediate temperature heat release in octane sensitivity of fuel with matching of RON , w...

juuhanaa wrote: ↑Sun Sep 25, 2022 3:57 pm By looking how Renault did things from the factory (which must be taken into account due to the rules) aand what the F3 head may look like, i think there are different ways to skin a cat...

They fill it with the upper intake access port or with both at the same time ?

Thank you kind words. Folkrace is fun class where i can do soft head stuff, and those experiments serve other series like rally and sprint. MB 147 rods has 22 top for BMW piston and 51.6 lower for Renault stock 93 crank. This combo with std block height ends up roughly 4mm material above top piston...

So far, the conversation has focused on squish band clearance and to a lesser extent on Squish Area Ratio, and a little on piston speed. Calculations based on the above will only yield average velocities. Actually, local squish velocities are determined by the shape of the squish edge window and ad...

Full Sonic condition maybe It Is too severe condition. Often the minimum section in intake Port Is sized to have Max 0.5/0.6 mach. Let's suppose then to have on a section of the intake Port 0.5/0.6 mach or in other Word a choke condition, what would be in this case the answers tò my questions? For ...

This engine has basically zero squish but a lot of tumble with intake port angle normal to the exhaust valve and no piston crown, tumble which will be well broken down to small eddies near TDC by the combustion chamber shape. Yeah, the huge stroke helps to reduce the dome volume massively when keep...

Yes engive can rev 8k, but with a 258@seat cams i have shifted close 7500 with a different intake setup, but i never dyno that combo, so i just dont know what output it made.. The 7500 rpm sounds interesting. Do you have an assumption from the but-meter where peak power was? Yes mainly F7R engine b...

Can you please elaborate on the fuel used for this engine and what is its intended use? Toluene has quite a good MON, RON rating: 112 and 124 respectively. With the math done you have to mix 84 % Toluene with 16 % n-Heptane (0 RON-rating) to get a 102 RON rating, which was necessary to pass the RON...

- what happen to the fuel mixed in the air? It Will be further atomized or It Will condensate in liquid deposit on the Wall of the Port? - what happen to the pressure waves when they cross the sonic section? Will they be stopped or they Will pass trought the Sonic section? - Will the Sonic Speed in...

Now this is a very interesting statement. Could you please elaborate further on this if possible? The rules said 102 RON that time, which lead to pre-ignition, heavy knock and other disadvantages. To be able to get the boost up BMW and others exchanced a bigger amount with toluene (maybe most of it...

My cams are like 258@seat/178@1mm and 9.3mm lift, so i dont have valve train issues. That's an interesting approach. What would be the redline of this engine with that cam duration? On a 2-Liter NA engine .5mm lift@TDC is enough to make 1.5ft lbs/cid from 4000rpm-5500rpm. This is done using modifie...

...how about crazy slow lobe and better combustion chamber/piston shape? You mean slow on valve lift, in such a way that scavenge phase get the name worth and lift harder later with the aim to let the piston design need no valve reliefs? Two things why this won't be the optimum: cam lobe design nee...

Thanks for the pictures L.E. , I could not help but notice the labeled as an F-1 Rod was an H-Beam Design. Is that F-1 rod a fairly recent one ? Mark H. This is from the Paul Rosche Formula 1 engine (started end of the 70'ies), which had the highest ever used power in Formula 1. BMW run that progra...