jon this same topic and Hp formula came to me around 20-25yrs ago,(we never arrived at a useful answer).

think about this , a Formula 1 engine makes 800hp at 18000rpm but only 250lbs.ft torque, car stalls out at 8000rpm!

and modern diesels can make 800 torque at 2000rpm, engine cant rev past 3800rpm anyway?

or just force feeding it,aka, turbo/supercharging it, and saves a lot of work of porting, polishing, valve sizes, big TBs,etc.

 

i would really like to see someone make an actual 500hp,using a Jag V12!

500 at the flywheel would be great, just cant see anyone making 500 at the wheels!

unless some one steps up and force feeds the beast, turbo/supercharging!

 

I tend to agree, TWR made 500hp from the Group A and most of the power above 5000rpm not very useful on the road. Everything TWR did to get more power from the 5.3 moved power from under 4000rpm to over 5000rpm. The only way is to increase CI's. Listers 7.0L made 500hp.

I think 400-450hp is a realistic goal while keeping the V12's excellent low-mid torque.

 

jon, here is one for you to try, my 1978 XJS roadster, weighs in on a calibrated digital scale, at 3360lbs, 1/2 tank fuel ,and no driver!

that will keep you guessing for a while! roughly each 100lbs you remove gives around a tenth of a second off your 0-100mph runs! (on a 4000lb car).

 

'seems that 18 hp and a lot of torque is all some really need

https://www.youtube.com/watch?v=FLQhvruimfs#t=185

 

That steam tractor used the green one as a rototiller to plow the field.

 

i been pushing torque over HP for 24yrs, but most would just laugh, saying a diesel is not a performance engine!

better not say that to AUDI and TDI performance cars.

Audi diesels have been banned in most USA sports car race series(ALMS) IMSA. they use them in the LEMANS 24hr race ,where they won 5-6times, even after they changed the rules, by adding weight penalties, air inlet resrictors, and smaller fuel tanks.

altho lately things have moved to HYBRID race cars!

my project is a Audi V12 diesel engine in an XJS, factory stock 500hp 700 torque, remapped ECU 650hp 800 lbs torque(engine weighs close to the same as Jag V12 engine, figures show 25 lbs lighter). and you never even have to take the engine apart.

i went to a race at Road America WI, last time they allowed Audi Diesel cars, on the main straight,coming off a corner, Porcshe engines screaming at 10,000 revs and the Audi just sailed past them,sounding like they were just puttering along,in the pits i asked what kind RPM audi doing on the straights,4500-5000rpm!

so engines last much longer, use 30-40% less fuel, and reasonably quiet!

old carroll Shelby said "HP sells cars, torque wins races"

head of Audi engineering "people think they are buying HP, when they are really buying torque"

 

utube BMW Alpina D3 biturbo,vs BMW 3 series petrol(gas).

quality and performance in one package!

 

I will stand behind your theory on hp over torque. After going threw my training And several years of buildings
Cars. Torque over horse power is needed to push threw the gears and throw the car up the road.

 

Looks like we are making steel caps now; shown are standard, late Group 44 and what we have just had made. Our new caps are -0.010 to allow for line boring.





And fitted in the block



That should make it bullet proof, even at 10,000 revs.

 

beautiful pieces, you are getting serious, with you engine build!

darn, i miss the machine shop!

maybe start another thread? to follow your build?

also glad to see you give Grp 44 its due recognition, i have seen there cars run many times at Daytona race track!

 

the Austin-Healy I had that I mentioned earlier with the 4.80:1 rear end
legally weighted 1500lbs... the whole front of the car (speedwell type) with headlight buckets and wire harness weighted 35lbs... back then I weighted 97lbs... now I weight x2 that no torque... but when you wound it up past 6k rpm she went...!
I say legally 1500 lbs because that is what D modified SCCA solo II rules required back in the day... back then I went a season of 10 regional events 9 first places and 1 2nd place.... (every one has an off day I guess) now I am just happy to enjoy this XJS.... and fixing it up.... and motoring around...she is quick 40 to 60 in traffic when I want to pass... some one...

 

You do realize I have 2 x XJR5's in my workshop, lol
Been racing 1 of them for a decade.

The std cast caps just dont make it at the level we are talking about, even cracked the caps in modified XJRS engines. Yes you can get away with std much of the time but when it goes wrong it goes wrong.

 

xjr5006, you mentioned is a previous post to machine the pad off the rod cap. How much should I remove?

Is it safe to remove the section in white

 

OK at the little end you linish away all of the balance pad so that the outside of the little end is nice regular and smooth, You linish away all the seam on the outside of the rod from top to bottom , both sides, so the rod looks like the XK version, At the big end you remove most of the balance pad so that you just still have the width but no longer have the depth. I have seen a set with slightly more than this so that the width is also removed Never seen as much removed as you have marked on the rod shown, Dont think I would risk that much; remember the main stress will be in the center. The metal removal is straight at the big end ie as if the rod is milled straight across, do leave a little more than you think so as to allow balancing across the set. Try and get the set to the gram. You can always remove more if its there to remove, you cannot add to 1 rod if you go too far.
Hope this clarifies, Remember that removing under 100gms per rod can total over 1Kg is reciprocating weight. A driver will feel the difference particularly if its a manual with lightened flywheel.

 

on mine i also had them shot-peened after some metal removal and polished, plugged both inside machine ends,so as not to mess up the inside surfaces.

 

Block with new caps line bored ready for crank.





Crank (92MM) being checked for use if no one wants it. It was fine.

 

Absolutely lovely. Excuse my ignorance, but what are those allen key-like inserts in the crank?
And what is this engine going to be used in, a road car or a racer? Congratulations, anyway.

Greg

 

maybe for some of the oil drilling passages, or cleaning out passages!

 

do you know where(what country) the raw forgings were manufactured in?

and where the actual machining was done?