Yeah, isn't the '04+ TL really a DOHC?
It has 2 valve covers and 2 cams shafts but it's called a SOHC....

Can someone explain why it's called a SOHC?

My mom's '93 Mercury Villager V6 is also the same but it's called a SOHC?
WTF?
It also has 2 valve covers and 2 cams shafts but it's called a SOHC....
WTF! WTF! WTF!




Modified by YiNYaNg at 8:53 PM 8/14/2007

 

its SOHC because its 2 heads but 1 cam per head so 1 cam + 1 head = SOHC the TL has 2 SOHC heads .....lol

 

lol. yea 1 cam per head would be SOHC lol. NSX has 4 cams, 2 heads, therefore it would be a DOHC V6.

 

DOHC = 2 camshafts over each cylinder head

SOHC = 1 camshaft over each cylinder head

 

Quad cam?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by CompanyFlow &raquo;</TD></TR><TR><TD CLASS="quote">Quad cam?</TD></TR></TABLE> the nsx yeah

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 361 accord &raquo;</TD></TR><TR><TD CLASS="quote"> the nsx yeah </TD></TR></TABLE>
no, the NSX is DOHC, 2 cams per head.... a Quad cam is 4 cams per head ...like subarus....and some toyotas...

 

wtf i, next you are going to say STi's have V6's?

who the hell wand 4cams on one cylinderhead

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 361 accord &raquo;</TD></TR><TR><TD CLASS="quote">wtf i, next you are going to say STi's have V6's?

who the hell wand 4cams on one cylinderhead</TD></TR></TABLE>
my bad it was a typo.... i didnt explain enough either...
but some subies and toyotas are considered quadcam cause they are 4cyl with 4 cams

 

My Lexus LS400 is a quad cam V8.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by dragncivic &raquo;</TD></TR><TR><TD CLASS="quote">
my bad it was a typo.... i didnt explain enough either...
but some subies and toyotas are considered quadcam cause they are 4cyl with 4 cams</TD></TR></TABLE>

lol ok

 

because they wantt to fine tune each intake valve opening and closing.

GM had a notoriously unreliable Quad 4 engine that was a quad cam

 

I have a DOHC on my GSR

as well as

DOHC on my Cobra.

DOHC FTMFW!

 

save the sohc


not my car

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by YeuEmMaiMai &raquo;</TD></TR><TR><TD CLASS="quote">because they wantt to fine tune each intake valve opening and closing.

GM had a notoriously unreliable Quad 4 engine that was a quad cam</TD></TR></TABLE>

The Quad 4 was a DOHC 4-cylinder. Only 2 cams.

 

Best way to explain it.

DOHC = Dual Over head Cam
SOHC = Single Over head cam

Thus Dual Over head cam mean two cams per head. Thus same with Single over head cam. The TL V6 only has One cam per head. thus the V6 on the J-series (TL V6) is considered a SOHC.

The NSX C30 or C32 is considered a Dual Over head cam. Two cams per head. basically its like getting two Type R B-series heads on a V style Block.

The TL V6 is like getting two D-series SOHC heads on a V style block.

Thus the TL V6 is considered a SOHC V6

The Subys are still DOHC. two cams per head. but you need 4 cams to complete the valve train. Thus why the cams on a DOHC V6 or Flat 4 is like double the price to upgrade the cams.

I hope that breaks it down. basically its what everyone else stated above!!!

 

As confirmed, the TL and all Acura/Honda J series V6 motors are SOHC.

Briefly if I might beg the question that some might be thinking... Then isn't a SOHC engine inferior to a DOHC?

Theoretically, the answer is yes, since DOHC designs allow for improved pumping efficiences/flow through the system. Additionally, DOHC designs allow for indvidualized valve & lift timing between the intake & exhaust cams...i.e., one can customize the tuning of the engine better than currently possible with a SOHC design.

Having said the above, however, SOHC designs, particularly Honda's represent some advantages. Perhaps another way to say this is that DOHC designs represent some trade-offs...there are downsides to DOHC motors:

1. Honda's SOHC J Series V6 motors have a 60 degree angle between the pistons. Many DOHC designs require 90 degrees since the head must be wider to accomodate two overhead camshafts per bank of cylinders, not one...such occupies more space. The downside is DOHC engines tend to be larger & require more room in the engine compartment. Larger might mean greater forward placement in the engine compartment (w. exception of mid-engine layouts such as in the NSX) which tends to increase chassis understeer.

2. DOHC motors tend to be heavier than SOHC designs. This inherently tends to be a bad thing re balancing the chassis, fuel economy, tire wear, etc.

3. DOHC motors are more complex. Theoretically, more parts means less reliability. In practice this might not always prove true, yet simpler (SOHC designs ) should prove to be more reliable, & certainly cheaper to maintain. The trade-off w. Honda is that they employ their VTEC system which adds complexity. Honda has in effect traded away DOHC for VTEC, and ended up at about the same place in performance, except their motors enjoy the benefits mentioned here of SOHC designs.

4. Because Honda's SOHC designs cost less that DOHC & because they their J Series shares many components between them (J30, J32, J35, & J37), they are most likely cheaper to manufactuer than competitor's DOHC engines. This savings plays out in the markeplace to Honda's advantage in several ways:

a. Honda could sell its vehicle for less if it wanted...
b. Honda could charge the same as competitors & enjoy healthier margins...
c. Honda could direct savings into other vehicle amenities, adding overal 'value' to their line of cars (they tend to come 'loaded' w. features, this is how Honda goes to market).

Note: Honda is soon to release its 'Advanced VTEC' design which will bring certain DOHC functionality to their line of SOHC motors. Their Advanced VTEC will either/and/or bring increased fuel efficiency along with increase output for any specific engine design. Honda 'could' well decide to continue with honed verisons of its J-series motors utilizing Advanced VTEC. Example: a 330HP J37 installed in an Acura RL & a 300+ HP J35 installed in the '09 TL could be winning tickets...