engine limit?
Hi,
What is the maximum engine displacement for csr? I have seen three csr cars for sale with engines in the 1800cc range. I thought the limit was 1665cc. Are six cylinder engines allowed?
Thanks,
engine limit
Hi,
Would a 1700cc v4 with four 10" wheels be considered to big for csr? Weight wise I'm sure I wouldn't be a tremendous threat. Generally, is 1665cc the limit?
Joe
Lee Stohr
Unregistered User
(7/12/01 11:15 pm)
Rules
I'd like to understand the CSR engine rules too. I've designed a few cars for other classes, but I get a headache every time I read the CSR rules. The first page of engine variables is confusing, but then there is a second page of what appears to be individual exemptions for every weird car that some guy somewhere wants to run in CSR.
For those who have no experience with CSR, the rules are just incomprehensible. Especially when you try and figure out what weight goes with what engine/carb/etc. If there are others as confused as me, it sure would help to have a sentence by sentence explaination, at least of the first page of engine rules.
You really should get a copy of the SCCA rule book. My interpretation may be flawed. Section A.2 of the Sports Racer Category Specificatoins starts with a table that says:
850cc -1300cc 2cycle or 4 valves per cylinder max may be used with unrestricted induction.
upto 1400cc OHC crossflow 2 valves per cylinder can be used with carburetors only.
upto 1615cc OHV crossflow or non-crossflow or OHC non-crossflow 2 valves per cylinder are premitted with unrestricted carb/FI provided a 37mm venturi is used ahead of the throttle butterfly valve. (this is getting to the part where Lee's head hurts)
upto 1615 OHC crossflow 2 valves per cylinder are premitted with unrestricted carb/FI provided a 37mm venturi is used ahead of the throttle butterfly valve.
Rotary Mazda 12A prepared to GT3 preparation rules are permited, but must use 48mm IDA carb with 36mm venturies (this was new for 2001, but may have been modifed with a later Fastrack item.
Rotay Mazda 12A non-peripheral port, non-bridge port is permitted with unrestricted induction.
I am not going to type the entire section, but an important is "All engines in the CSR class over 1300cc shall be derived from cars listed as eligible for the SCCA production or GT category" and later "C Sports Racing engines over 1300 cc may be modified as provided for in the current GT-2, 3 and 4 rules except that bore, stroke and flywheel are unrestricted provided the displacement limit is not exceeded."
Hope this provides some broad parameters, but be sure a read the complete section of the rule book, as Lee points out, there are lots of "exceptions" for specific engines.
engine limit
David: If 850 - 1300cc 4 valve per cylinder engines are allowed turbos under the unrestricted induction rule, watch out for some BIG hp. Even at 850cc, a four stroke turbo engine can be reliably made to produce 300hp (not motorcycle derived). This same condition exists in DSR but nobody to date has properly exploited turbocharging a 620cc engine. The possibility of this may rest with the fragile nature of a motorcycle crank case. However, if some enterprising soul decides to whittle a piece of T6 into a purpose-built crank case, well, just think of the possibilities.
enginelimit
Yes Ted, I mean aluminum. The stuff makes great crank cases. Are we talking about the same thing? I was referring to crank case not crank shaft.
engine limit
Thanks for the clarification, Rodger. Tom Clayton and I were trying to figure out if any language existed in the GCR that allowed or prohibited turbocharging in CSR. Our thoughts were that it probably was allowed but at what engine size. Tom also thought 1.7 was the factor generally stated somewhere in the GCR. Interestingly, the GCR clearly states that ASR engines can not be turbocharged but that 620cc DSR engines can be turbocharged. CSR says nothing but "unrestricted induction" with no mention of turbocharging or supercharging.
At 760cc's, the power drop would most likely be to 270hp. Now, at this level of power, there may be other good engines that make that kind of power without the extreme cost of prototyping. Any CSR racers out there making this kind of hp with correspondingly respectable torque?
I was trying to avoid typing in the the entire exception list included in the GCR/SRCS pg 8 (section 17.1.5.A.2). That section (new for 2001) says in part:
"Turbocharging or supercharging is allowed with a displacement factor of 1.7, restricted to 1300 cc equivalent (765cc). Restricted to 36mm Venturi(s)."
There's lots more. But as Lee indicated it will make your head hurt.
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