Euro 3.2 > 3.4 - DC19 or DC20?

[sp_cs]

Folks

i'm weighing up cam options on a rebuild of my Euro spec 3.2. Looking at Motronic friendly Mahle 98mm P&Cs in 9.8CR guise, but massaged to 10.3:1 CR. FVD in Germany have a straight 10.3 option available, but costs approx £900 more.

Will be running single-plug ignition (UK based, 98/99 RON available).

Looking at DC19 (~ 20/21 spec?) and DC20 - anyone got real world experience on a 3.2/3.4. Don't want to go any more 'extreme' as its a road car and torque/driveability of more importance than ultimate power.

Haven't limited it to John's cams, but based on his 'accessibility' happy for my money to go his way.

Thoughts please?

SP

[ENTHUZD]

Originally Posted by sp_cs

Folks

i'm weighing up cam options on a rebuild of my Euro spec 3.2. Looking at Motronic friendly Mahle 98mm P&Cs in 9.8CR guise, but massaged to 10.3:1 CR. FVD in Germany have a straight 10.3 option available, but costs approx £900 more.

Will be running single-plug ignition (UK based, 98/99 RON available).

Looking at DC19 (~ 20/21 spec?) and DC20 - anyone got real world experience on a 3.2/3.4. Don't want to go any more 'extreme' as its a road car and torque/driveability of more importance than ultimate power.

Haven't limited it to John's cams, but based on his 'accessibility' happy for my money to go his way.

Thoughts please?

SP

I might also suggest a 964 grind... a little less aggressive, but still lots of power all the way up. I've had great luck with them on my Euro 3.2.

[89911]

I run Mahle 3.4l piston and cylinders with a 20/21 cam grind on my 89. It also is twin plugged. I've got about 4 years of "real world" experience with it. As far as being drivable and reliable. I've had no problems. The car has been driven extremely hard at the track and also taken to work later that week. I also has the G50 regeared to further the cars power range. No downside other then the expense.

[schnellmann]

I used the DC19 in my 3.4 build with the Motronic EFI. It's really great.

Very close to 20/21... slightly hotter than the 964 grind. I would have used the DC20 if I didn't need to pass emmissions. My build is documented at the link in my sig. Lots of impressions and data in the later posts if you're curious.

Also, because of the ramp rates of the DC19 lobes, you'll need heftier-than-stock valve springs.

[sp_cs]

Originally Posted by ENTHUZD

I might also suggest a 964 grind... a little less aggressive, but still lots of power all the way up. I've had great luck with them on my Euro 3.2.

Originally Posted by 89911

I run Mahle 3.4l piston and cylinders with a 20/21 cam grind on my 89. It also is twin plugged. I've got about 4 years of "real world" experience with it. As far as being drivable and reliable. I've had no problems. The car has been driven extremely hard at the track and also taken to work later that week. I also has the G50 regeared to further the cars power range. No downside other then the expense.

Originally Posted by schnellmann

I used the DC19 in my 3.4 build with the Motronic EFI. It's really great.

Very close to 20/21... slightly hotter than the 964 grind. I would have used the DC20 if I didn't need to pass emmissions. My build is documented at the link in my sig. Lots of impressions and data in the later posts if you're curious.

Also, because of the ramp rates of the DC19 lobes, you'll need heftier-than-stock valve springs.

Excellent, thanks all

What sort of power range do you guys think you have? Have you lost out anywhere?

When i emailed JohnD, he suggested the higher CR euro engines can run warmer cams and still have a very useable power range....hence my thinking of DC19, DC20.

I don't want/need my engine to develop power over 6500rpm, i just want to maximise the area under the power/torque curves up to this point. Make sense?

EDIT - forgot to add, SmartRP valve spring kit on order

Cheers,
SP

[drsimonwong]

Hi,

I have a blue printed Euro 3.2 10.31 with SSI's and with John's DC19. Large spread of usable power (or is that torque???). There is
"go" from 2000rpm and then another "kick" at 5000rpm. Doesn't seem to taper off at all to redline.

Little lumpier than stock at idle but not excessive. Will get SWchip reprogrammed soon for the cams now that I've just run in the new engine. Having my valves done at 5K and then off to the dyno.

My mechanic is impressed with these cams. Normally he uses 964 grind but I know he likes these better. Definitely recommended.

Simon

[sp_cs]

Thanks for your feedback Simon, all sounds promising. Good luck with your Dyno!

DC19 looking good....

[KTL]

I'd go with the DC 19 if your proposed pistons don't have valve reliefs. I have DC 20 in my engine with stock USA 9.5:1 3.2 pistons and I couldn't set my spec'd lift at TDC overlap due to inadequate piston-to-valve (P-V) clearance.

The spec for the DC 20 is 2.2-2.4mm. I could only get 1.8mm at overlap, while ensuring I was maintaining adequate P-V clearance. If you go with DC 19 (which specs a 1.8-2.0mm lift at TDC overlap), you're right in the range I was able to go with.

I don't purport to be some master engine builder, so maybe i'm way off with my statements. Just relaying the experience I have with my 3.2 9.5:1 stock pistons and the DC 20 cams. By the way I went with DC 20 knowing that i'd not be optimizing the use of my cams. I planned to increase displacement or go with Euro 3.2 spec in the future.

One question, why go with SRP springs? Dougherty sells performance springs too.

[ENTHUZD]

How does the DC20 and DC19 compare to 964 grind? Even less than DC19? With his Euro P's and C's, should 964 work well too?

[sp_cs]

Originally Posted by KTL

I'd go with the DC 19 if your proposed pistons don't have valve reliefs. I have DC 20 in my engine with stock USA 9.5:1 3.2 pistons and I couldn't set my spec'd lift at TDC overlap due to inadequate piston-to-valve (P-V) clearance.

The spec for the DC 20 is 2.2-2.4mm. I could only get 1.8mm at overlap, while ensuring I was maintaining adequate P-V clearance. If you go with DC 19 (which specs a 1.8-2.0mm lift at TDC overlap), you're right in the range I was able to go with.

I don't purport to be some master engine builder, so maybe i'm way off with my statements. Just relaying the experience I have with my 3.2 9.5:1 stock pistons and the DC 20 cams. By the way I went with DC 20 knowing that i'd not be optimizing the use of my cams. I planned to increase displacement or go with Euro 3.2 spec in the future.

One question, why go with SRP springs? Dougherty sells performance springs too.

Thanks for your input, interested to hear re DC20 - i thought only SuperCup cams had P-V clearance issues, will bear that in mind. The engine builder recommended the SRP springs, liked what he saw.....can't comment on DRC springs

Originally Posted by ENTHUZD

How does the DC20 and DC19 compare to 964 grind? Even less than DC19? With his Euro P's and C's, should 964 work well too?

agree 964 should work well, i wanted 20/21 spec which is closer to DC19 than DC20. 964+1 if you will. Dc20 more aggressive still, but supposedly still very much 'street-able'

[KTL]

DC20 > DC19 > 964 as far as agressive goes. DC20 is completely streetable. My car runs fine and suffers no ill effects at low rpms. Idle is a bit lumpy but it's not like the car doesn't want to run. Just sounds like the engine is more powerful. Granted it's not at full lift spec, but it's close.

DC20 is also referred to as "Super C2" on Dougherty's spec page

I have Dougherty's performance valve springs. My guy who assembled the heads had no issues with setting them up.

[drsimonwong]

When I chose the DC19 it was partly to do with the price differential to the DC20. My stock cams were reground to DC19 spec. where as they could not be reground to DC20.

With DC20 you need to buy a whole new camshaft set.

Simon

[89911]

My brothers 87 engine was rebuilt with Euro 3.2 P/C's and a 964 grind on the cam. It had the stock motronic unit and intake's. Extrudehoned them and opened the throttle body as much as it could go. We did all the springs and connecting hardware. He is using SSI's but is switching to headers next year. A custom tuned Steve Wong chip got everything where we needed it and it was putting out 225/wheels or roughly 255 horsepower. The 3.4 engine I did doesn't put out that much more horsepower, but the power band is lower and more usable. The regearing helps immensely.

[KTL]

Simon,

Price for a regrind of cams was same when I spoke to John and had mine done last year. DC 19, DC 20 can both be reground on a SC or 3.2 cam. See the legend/remarks about his cam profiles

http://www.drcamshafts.com/911profiles.htm

[JeremyD]

anything above a 9.8 to one and a DC 19 and you'll probably have to have valve reliefs cut.

I have 9.8 to 1 mahles and 993 SS cams and had to take about a mm for clearance.

It runs good though - but at the cusp of what I would call streetability.

[sp_cs]

Originally Posted by drsimonwong

Hi,

I have a blue printed Euro 3.2 10.31 with SSI's and with John's DC19. Large spread of usable power (or is that torque???). There is
"go" from 2000rpm and then another "kick" at 5000rpm. Doesn't seem to taper off at all to redline.

Little lumpier than stock at idle but not excessive. Will get SWchip reprogrammed soon for the cams now that I've just run in the new engine. Having my valves done at 5K and then off to the dyno.

My mechanic is impressed with these cams. Normally he uses 964 grind but I know he likes these better. Definitely recommended.

Simon

Hi Simon,

found this post earlier, suggests you may have the DC20 fitted?

20/21 cams

can you clarify please?

thanks