2TG cam specs needed for blank camshafts.

[BrianGT]

I have just got a pair of blank TRD cams for my hybrid and I need help with some specs.

I know there are some seriously knowledgeable 2TG guys on here and your input would be much appreciated!

The engine is a 1940cc 2/3T hybrid. It has been lightened and balanced, around 10.5 compression, 45 Dellorto's with 38mm chokes.
The cams at present are Group A (Per Ecklund spec) .... noticeably a bit peppier than standard.

The engine is superbly tractable, pulls 5th gear from 1800rpm and is limited by my right foot to around 6,500rpm where it is still pulling.
My inlet cam is advanced by around 5 degrees which gave a huge improvement in torque and only lost a few bhp at the top end. It's a great car to drive in traffic and yet turns in to a beast when the road is clear....both attributes I would like to keep!
I want to grind the cams to a spec that will give me a few more bhp but not all at the top end. I don't want to have to take it to 7k when I need to go forward as I had to when it was 1600......that became hard work!

At the moment there is a slight kick at around 4k and the engine pulls harder from then on......same cams in the 1600 gave a much harder kick and I would like a bit of that back hoping that the bigger capacity will still dish out the torque!

Any help is appreciated because I only want to grind them once!
Cheers,
Brian

[Celica RA45]

what kind of exhaust are you running extractors or std exhaust and are you out to 2.5 inches dia on the rear pipe at all
4into 1 will wake it up down low ,but you will need longer ram tubes and experiment with your 4 pipes etc

[BrianGT]

what kind of exhaust are you running extractors or std exhaust and are you out to 2.5 inches dia on the rear pipe at all
4into 1 will wake it up down low ,but you will need longer ram tubes and experiment with your 4 pipes etc

Thanks! I have a 4 into 1 extractor manifold in to a 2.25 dia stainless exhaust system. It's a Powerflow system.
I'm kind of stuck with what I have as far as modifying it is concerned due to all sorts of reasons, cost being one of them! I also forgot to say it has double valve springs.
I'm sure that I don't have a problem with valves hitting the pistons so a bit more lift than std would be ok......as I say I don't want the "ultimate power" grind.....just a bit more kick whilst keeping some torque.....a compromise I know!

Toyheads recommend a 292 deg with 11.7mm lift as a "great spec for a tuned N/A engine offering good driveability and wide powerband"......that lift might be a bit high for me.

What is a 288 deg and 10.8 lift like compared to a Group A cam....if in fact anyone knows those Group A specs.

Any thoughts are appreciated!

[Celica RA45]

also just thinking ,i had a group c 2tg motor that use to race at bathurst with 48mm webbers 10.8 to 1 on av gas etc but the best thing about it was the 4 ich spacer that was bolted to the inlet and then the webbers and then a 14 mm shaped ram tube on the ends this made the bottom end pick right up

[71TA22]

Brian,

I hate to say it but what you are chasing after with the kick at 4,000rpm on your 2 litre hybrid (the kick which you did have on the 1600 motor) is either cams that give little torque low down or a turbo.

What you have now found is how the 2 litre 2TG hybrid normally aspirated was so much more succesful in formula 3 than the lotus, alfa, fiat twin cams (in its time anyway).

the 2TG hybrid had much better low down torque and delivered it pretty seamlessly through the rev range. The others played catch up down the straights - if they were long enough.

RA45 is right - tune the inlet length. I have standard inlet manifold, misab plates, weber 45's and 65mm ram tubes.This does make a difference to the bottom end pick up.

Your exhaust system should be fine as it is.

Might be worth your while speaking to David Wild of DTW Engineering (I think) near London. They are aparently still working on historic formula 3, 2TG Nova motors so will have some nice expensive gear available.

[BrianGT]

Thanks guys....it's appreciated!

Mike....my inlet manifold is a std Toyota for the 2TG with side drafts, in my case Dellorto 45's. I have the same plates as yourself and around 60mm ram tubes.I'll measure them today!

I know what you mean about the torque of the hybrid. When I touch the gas pedal the car immediately goes forward in any gear and that's the Big difference between the 1600 and 1940........the 1600 thought about it first.

Forgetting that the hybrid has more power but because of the torque i know i could get over a mountain road much quicker with the hybrid because you are never really in the wrong gear so your analogy about catching up on the straights i fully understand.
I'm just hoping to get a little more top end power and still have some torque and I think a little upgrade in cam spec from what I have will give me that. It's just how far to go I'm looking for!

I will look up that company and see what I can dig up.

Cheers,
Brian