320bhp N/A 5 cylinder engine

[RT Mechanics]

Originally Posted by grh222

Hi Austen

If you haven't found out yet, the BTCC engines were developed at TWR by a guy called Charlie Bamber. He is currently MD of Menard Competition Technologies. The first BTCC engines produced about 260 bhp, but this guy altered the heads by machining the cam carriers off and remaking them as billet bolt on items, allowing the followers to be increased to 36mm dia so a more lift could be used on the cams, (about .825in on the inlet). The head face was also machined on the angle to alter the attitude of the ports to the chamber. (All of this was driven by the BTCC regs) . Using 13.5 :1 cr, this setup produced about 325 bhp.

Hope this is helpful. I'm not a Volvo engine expert, it's just coincidence that the story of the head is in this months Racecar engineering.

Looks like a great project - nice to see something other than Duratecs.

All the best

Graham Hill

Hi Graham

Thats very interesting will be great to see how Austen gets on best of luck to him

Russ

[austenw]

Originally Posted by grh222

Hi Austen

If you haven't found out yet, the BTCC engines were developed at TWR by a guy called Charlie Bamber. He is currently MD of Menard Competition Technologies. The first BTCC engines produced about 260 bhp, but this guy altered the heads by machining the cam carriers off and remaking them as billet bolt on items, allowing the followers to be increased to 36mm dia so a more lift could be used on the cams, (about .825in on the inlet). The head face was also machined on the angle to alter the attitude of the ports to the chamber. (All of this was driven by the BTCC regs) . Using 13.5 :1 cr, this setup produced about 325 bhp.

Hope this is helpful. I'm not a Volvo engine expert, it's just coincidence that the story of the head is in this months Racecar engineering.

Looks like a great project - nice to see something other than Duratecs.

All the best

Graham Hill

Hi Graham

Thanks for the info

0.825 is almost 21mm of lift, WOW

I'm running the new style Volvo head with 32mm solid buckets and have had some 14mm lift cams made with over 300 deg duration

Ive had some extensive headwork done with welding to the inlet ports to increse the longside radius to increase flow.

I've fitted smaller stem valves to reduce weight and I'm running 35mm inlet and 31mm exhaust valves

Thats 4mm larger on both inlet and exhaust

Theoretically according to the calculator with the area of valve it should make 354bhp with silly cams

I'm hoping to get it over 300bhp with a redline close to 10'000rpm as I dare

Also running high comp at 13:1


I read somewhere that the touring car regs limited there rpm limit to something like 8500rpm?


I'm also running a sligtly larger bore to take the engine to a 2.1




As for progress of the build the head is still getting the new cams made as the first set would not fit this style head correctly (850 cams)

Should hopefully have some head flow numbers back by the end of the week from the flow bench

Dry sump pan is back from the machine shop so will post up pics soon

10 inj Inlet system is all done and finished ready to bolt on

[austenw]

[austenw]

Here is the TWR BTCC engine








The cam position in the head above looks pretty standard to me

I struggled to fit 14mm lift cams in the rocker cover with the base circle reduced 2mm from standard, it required extensive machining of the head and cam cover for them to fit

There is barely enough aluminium in the head and rocker cover to take away without welding extra material to the outside of the head to allow machining.

For clearance with 21mm lift cams they should be sticking out the top of the cover unless the base circle is very very small

[shimon340]

hi there!

A very interesting post! I'll read it in more detail later but had a quick look at the pics! Nice!

Re Racecar engineering...gonna get myself a copy somehow!

Re TWR engine, nice that volvo now displays one of them in the museum. Had a good look last time I was in Sweden. The Cambelt is rather thick affair (nice!), wonder where they source them from? The engine is dry sumped and there is an additional pulley at the base of the engine driving a larger oil pump. Tensioner setup is different too. Might have some more pics of that if you want!

[don kalmar union]

I believe that these engines were also turned arround and virtually laid on their side as far back as possible.

Regards, Don.

[RT Mechanics]

Originally Posted by shimon340

hi there!

A very interesting post! I'll read it in more detail later but had a quick look at the pics! Nice!

Re Racecar engineering...gonna get myself a copy somehow!

Re TWR engine, nice that volvo now displays one of them in the museum. Had a good look last time I was in Sweden. The Cambelt is rather thick affair (nice!), wonder where they source them from? The engine is dry sumped and there is an additional pulley at the base of the engine driving a larger oil pump. Tensioner setup is different too. Might have some more pics of that if you want!

Hi Shimon

Do post any pics you have some of us volvo nuts would like it

Russ

[shimon340]

hi there

ok, I'll try to post them soon!

[austenw]

[foggyjames]

That's fascinating. Only the 'guts' of the head remain, and the cam carrier and cover have been replaced. That explains the apparantly lack of work on the engine in the factory - it's not what was actually in the cars.

A guy on Turbobricks posted a rather cryptic comment recently about the engine in the Volvo museum, saying "It's hilarious how different that is to the actual race engine". I guess now we know what he meant!

cheers

James