john.r.davies Posted September 12, 2021 Report Share Posted September 12, 2021 Conversation on FB about the performance that can be got from a 2.5L engine. 200bhp from flowing, raised compression, Pi and a 6-3-1 exhaust. 260 from a full race engine - steel crank, over boring, very high compression and revs, etc etc. What does the TRR think of such claims? Quote Link to post Share on other sites
Motorsport Mickey Posted September 12, 2021 Report Share Posted September 12, 2021 (edited) Depends on who is doing the claiming John, and are they talking flywheel ? Trouble about Facebook are the numpties who post there, makes believing a leap of faith unless you know them. 6 cylinders not my forte and Neil ( Ntc) will have a good angle on these numbers. A current racer like Dave McDonald will also have good feedback on them. Mick Richards Edited September 12, 2021 by Motorsport Mickey Quote Link to post Share on other sites
tr7v8 Posted September 12, 2021 Report Share Posted September 12, 2021 As a standard TR6 engine makes 150bhp another 50bhp from modifications hardly seems a wild claim. With a steel bottom end, the higher rev limit will only raise this figure. Quote Link to post Share on other sites
ntc Posted September 12, 2021 Report Share Posted September 12, 2021 (edited) 30 minutes ago, tr7v8 said: As a standard TR6 engine makes 150bhp another 50bhp from modifications hardly seems a wild claim. With a steel bottom end, the higher rev limit will only raise this figure. No it does not. And never did that comment just fuels the nonsense as Mick said. Edited September 12, 2021 by ntc Quote Link to post Share on other sites
Dave McDonald Posted September 13, 2021 Report Share Posted September 13, 2021 I believe 260 bhp has been achieved - but not for long if you get my drift. 240 is a more realistic reliable figure from several full race engines, all built by several different specialists, with steel crank and rods, forged large bore pistons, special head gasket to suit, high compression, high lift cam, roller rockers, 6 - 3 - 1 exhaust, lightweight skeletal flywheel, gas flowed head and an ATI harmonic crank damper. Triple 45DCOE carbs. They will run to between 7200 - 7400 rpm but max power will be at around 6800 rpm. Dave McD Quote Link to post Share on other sites
john.r.davies Posted September 14, 2021 Author Report Share Posted September 14, 2021 Thank you, Dave! You were one of the people I hoped to hear from, for realistic information. JOhn Quote Link to post Share on other sites
Andy Moltu Posted September 14, 2021 Report Share Posted September 14, 2021 250 is a figure that has been claimed from a number of reliable sources on a fully worked race engine. Longevity is probably not the concern of those that afford the goodies required! Reasonably easy to get 180+ for a reliable and drivable road car. Beyond that drivability is starting to be compromised but PI is very forgiving allowing some wild cams to be set up to be drivable. 30 years ago I recall Chestnut House fitting their race cam into road cars with adjustments to cam timing. Drove well enough but fuel consumption of 16mpg! Quote Link to post Share on other sites
alan57 Posted September 16, 2021 Report Share Posted September 16, 2021 I seem to remember someone once saying "torque makes cars fast, power makes engine builders rich"!!!! Quote Link to post Share on other sites
stuart Posted September 16, 2021 Report Share Posted September 16, 2021 1 hour ago, alan57 said: I seem to remember someone once saying "torque makes cars fast, power makes engine builders rich"!!!! Horsepower is how fast you hit the tree, torque is how far you moved the tree. Stuart. Quote Link to post Share on other sites
hoffman900 Posted October 11, 2021 Report Share Posted October 11, 2021 (edited) I've seen a 5 port A-Series with modern development and fuel injection make 165bhp... 126 hp/L. Efficiencies decrease with engine size, but I have no doubt with a proper modern development regime, over 260bhp is possible. Edited October 11, 2021 by hoffman900 Quote Link to post Share on other sites
roy53 Posted October 19, 2021 Report Share Posted October 19, 2021 On 9/16/2021 at 4:02 PM, alan57 said: I seem to remember someone once saying "torque makes cars fast, power makes engine builders rich"!!!! I am sure i had the same person say to me , torque wins races , BHP sells engines we did both use the same engine builder. On 9/13/2021 at 3:49 PM, Dave McDonald said: I believe 260 bhp has been achieved - but not for long if you get my drift. 240 is a more realistic reliable figure from several full race engines, all built by several different specialists, with steel crank and rods, forged large bore pistons, special head gasket to suit, high compression, high lift cam, roller rockers, 6 - 3 - 1 exhaust, lightweight skeletal flywheel, gas flowed head and an ATI harmonic crank damper. Triple 45DCOE carbs. They will run to between 7200 - 7400 rpm but max power will be at around 6800 rpm. Dave McD Ditto i have dyno readings showing these figures ROY Quote Link to post Share on other sites
john.r.davies Posted October 19, 2021 Author Report Share Posted October 19, 2021 On 9/16/2021 at 5:18 PM, stuart said: Horsepower is how fast you hit the tree, torque is how far you moved the tree. Stuart. Trees hardly move, even when hit full force by a car: Quote Link to post Share on other sites
RogerH Posted October 19, 2021 Report Share Posted October 19, 2021 52 minutes ago, john.r.davies said: Trees hardly move, even when hit full force by a car: Not enough torque then. Roger Quote Link to post Share on other sites
hoffman900 Posted October 20, 2021 Report Share Posted October 20, 2021 The torque saying should be revised: Producing the most torque at the highest amount of RPM wins races Quote Link to post Share on other sites
Motorsport Mickey Posted October 21, 2021 Report Share Posted October 21, 2021 +1 with that. Mick Richards Quote Link to post Share on other sites
Andy Moltu Posted October 21, 2021 Report Share Posted October 21, 2021 A good example of why not to stand on the outside of a bend. Quote Link to post Share on other sites
andyhall Posted October 23, 2021 Report Share Posted October 23, 2021 On 10/20/2021 at 7:21 PM, hoffman900 said: The torque saying should be revised: Producing the most torque at the highest amount of RPM wins races And how do we mere mortals go about achieving this?? Quote Link to post Share on other sites
roy53 Posted October 23, 2021 Report Share Posted October 23, 2021 open walet and close eyes. Quote Link to post Share on other sites
stuart Posted October 23, 2021 Report Share Posted October 23, 2021 5 minutes ago, roy53 said: open wallet and close eyes. and repeat after me "Help yourself!" Stuart. Quote Link to post Share on other sites
MichaelH Posted October 26, 2021 Report Share Posted October 26, 2021 Can I reopen this line of thought as we have discussed max BHP then agreed that Torque figures are perhaps more significant What FTlbs torque have been achieved with four cylinder and six cylinder cars I was trying to sell my racer and put the car on the rolling road with AP in Blidworth results were:177 BHP @6575 revs and 150Ftlbs @ 4990 revs Engine as full race as i can make it to FIA spec (87mm pistons) Any other offers? Quote Link to post Share on other sites
Motorsport Mickey Posted October 26, 2021 Report Share Posted October 26, 2021 Hi Michael...flywheel ? Mick Richards Quote Link to post Share on other sites
MichaelH Posted October 26, 2021 Report Share Posted October 26, 2021 No at Wheels Michael Quote Link to post Share on other sites
Motorsport Mickey Posted October 26, 2021 Report Share Posted October 26, 2021 Good figures Mick Richards Quote Link to post Share on other sites
Motorsport Mickey Posted October 27, 2021 Report Share Posted October 27, 2021 The figures for my car in 1988 164 lb ft torque at 5300 revs and 165 BHP, at the wheels. That's with 89mm pistons standard crankshaft but stroked and using -60 thou big ends, with standard con rods and with 45 Webers fitted. I used a 6000 rev limit with a limiter at 6250 revs. Mick Richards Quote Link to post Share on other sites
MichaelH Posted October 28, 2021 Report Share Posted October 28, 2021 Very impressive and interesting, your engine is 140cc bigger and with the standard crank stroked to 60 thou - I make that 93.5 stroke and +2mm piston size, your engine is 6% bigger and 10% more torque and at higher revs. the other difference is that I run 48DCOEs and you run 45s Perhaps I should run 45s? Any thoughts out there MichaelH Quote Link to post Share on other sites
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