Four vs Six, comparison questions Options

[johnmhudson111]

I am sure ths has been discussed before but I couldn't find anything using the search. So, has there been a comparison done between a 911 six and big four, like Jake Raby's engines? Looking at:
1. Overall cost of engine (plus consideration of the cost of the conversion to a six from a four)
2. power hp/tq
3. engine life
4. other issues?

[phantom914]

This is a recurring topic. When you did the search, did you select "any date"? The default searches only 30 days back.


Andrew

[john rogers]

I went through this a while back and here is what I found. Both the 2.7L four I had and my 2L six have 185 HP at the rear wheels on the dyno. The four would last about two race weekends and need work. The six has been in 1 1/2 years and runs right along as it was made to rev to 9000 RPM and I rarely go over 8K. The four was easier to drive, only had to shift into fourth once at Willow Springs to go over the hill as the four had much lower and flatter torque curve. With the six I shift all the time, even into 4th at turn nine. The cost of five years of engine work on the four was probably much higher than the cost of the six conversion, but I have never added it up. Both engines were dry sumped with front oil coolers so no difference there. Many will say a big four can be made to last but with road racing the high horse power fours will not last as long as a comparible six. If you cut the power back to say 130 at the rear wheels they would last longer and to be competitive really cut weight of the car down to 1800 pounds, you can win against the six's easily.

[grantsfo]

I have done extensive research on this subject. The 6 is the way to go in my opinion especially if you think you will ever bring the car out to the track. Regardless of the claims you hear the Type 4 is not up to the rigors of extensive track sessions if you want an engine that will last more than a season or two.

If resale value is a consideration regardless the reputation of a given type 4 engine the car wont hold same value as a 6 conversion. 6 conversion can be done very cost effectively when compared to a well bult big Type 4 such as the ones from Jake.

If money doesnt mean anything to you then a big Type 4 is cool and Jake is one of the best around. I just cant justify the expense of a well built big type 4 when I look at the benfits and costs of going with a 6 conversion.

[johnmhudson111]

QUOTE (phantom914 @ Aug 16 2005, 10:06 AM)

This is a recurring topic. When you did the search, did you select "any date"? The default searches only 30 days back. Andrew

Yep, found a lot of information on six conversions and a lot on bigger fours, nothing with a comparison of the two. (IMG:http://www.914world.com/bbs2/html/emoticons/confused24.gif)

[Trekkor]

This is always a fun topic, because some people lose all control and sense of reason and take offense like it's a personal attack on their family or something. (IMG:http://www.914world.com/bbs2/html/emoticons/dry.gif)

I've had a stock 1.8 and 2.0 FOUR. Very fun car to drive.
Now I have the 2.0 SIX.
To me there is no comparison SIX vs. stock FOUR.
The SIX is free revving, high rpm's with faster acceleration. Then there is the SOUND of the Webers, big fan and chains. Try to take your stock FOUR to 7300 rpms and see what that sounds like... (IMG:http://www.914world.com/bbs2/html/emoticons/unsure.gif)

Built FOURS- that's another story in itself.

Consider this: you can do a budget SIX conversion and buy one, maybe two good running back-up 2.7 motors at $4000 each for the price of a custom built big FOUR. No joke. (IMG:http://www.914world.com/bbs2/html/emoticons/ohmy.gif)

My plan is to always have a SIX.


KT

[redshift]

There are many people out there with +200k miles on 3.0/6 street motors, that still pull 200+ hp.

In HiPo /4 motors, you have to have head work done often... hell... in non-hipo /4 motors.. you have to do head work.. often.

(IMG:http://www.914world.com/bbs2/html/emoticons/smile.gif)

tic tic tic tic..


M

[SirAndy]

while i agree with most of the above, the big /4 has at least 2 advantages ...

- less weight
- better torque curve (much better low end torque)

- for street use, it's a toss-up. both can be a lot of fun for the money and both can be build to be reliable ...
- for the big track, go with a big /6 as you'll like the higher rpm HP ...
- for AX, go with the big /4. less weight and better low end torque will more than make up for less high rpm HP ...

just my 2 cents of course ...
(IMG:http://www.914world.com/bbs2/html/emoticons/cool.gif) Andy

[goose2]

Generally, I think a stock six will outlast a built 4 (Jake's motors may be the exception, but cost as much as a six conversion). Power can be similar. 4 weighs less. A highly tuned motor can be a PITA for street use. These are all gross generalizations....it's a close call in my opinion.

[airsix]

QUOTE (trekkor @ Aug 16 2005, 07:56 AM)

This is always a fun topic, because some people lose all control and sense of reason and take offense like it's a personal attack on their family or something. (IMG:http://www.914world.com/bbs2/html/emoticons/dry.gif)

Ah yes... the 914world.com version of the 'scientific method'. (IMG:http://www.914world.com/bbs2/html/emoticons/chairfall.gif)

Step 1: Someone asks a very good question.
Setp 2: Side 'A' makes outlandish unsubstantiated claims.
Step 3: Side 'B' makes outlandish unsubstantiated counter-claims.
Step 4: Both sides comence with personal attacks.
Step 5: Third parties request objective data for evaluation.
Step 6: Sides 'A' and 'B' lynch third parties.
Step 7: In the future, new club members read old thread.
Step 8: Some of these new readers accept the unsubstantiated claims as gospel.
Step 9: Rinse and repeat.

-Ben 'gimme unbiassed objective data' M.

[Jake Raby]

I won't even go there this time!!!!!

All I'll say is that there is NOTHING on this earth better than handing the driver of a six cylinder car his ASS on a silver platter with a 4 cylinder pushrod engine......

[goose2]

QUOTE

Ah yes... the 914world.com version of the 'scientific method'

unbiased?...objective?.......no such thing. My dad used to say "I have an open mind...everyone's entitled to their own stupid opinion" (IMG:http://www.914world.com/bbs2/html/emoticons/laugh.gif)

[SirAndy]

QUOTE (airsix @ Aug 16 2005, 09:37 AM)

'gimme unbiassed objective data'

does my butt count as a "unbiased scientific method"? (IMG:http://www.914world.com/bbs2/html/emoticons/idea.gif)

if so, i stick to what i have said ...
(IMG:http://www.914world.com/bbs2/html/emoticons/cool.gif) Andy

[SirAndy]

QUOTE (Jake Raby @ Aug 16 2005, 09:43 AM)

All I'll say is that there is NOTHING on this earth better than handing the driver of a six cylinder car his ASS on a silver platter with a 4 cylinder pushrod engine......

i don't know ... (IMG:http://www.914world.com/bbs2/html/emoticons/unsure.gif)

i'd rather spend a whole night in bed with 3 cute girls ...
(IMG:http://www.914world.com/bbs2/html/emoticons/mueba.gif) Andy

[lapuwali]

For purely street use, one consideration against the six is noise. That big fan pointing directly at the firewall is LOUD. I had relatively little intake noise and little exhaust noise on my 2.4 CIS Six, yet you still had to shout at the passenger at freeway speeds because of the fan noise. For a weekend toy, this is tolerable. For a regularly driven car, however, it gets very tiring. With K&N filtered Webers, you have even more noise.

Granted, these are all wonderful noises; few things sound better than a Six wound out. Too much of a good thing, IMHO.

Comparing the costs of a Six conversion v. a big four by saying the four is more expensive, however, is stretching the point a bit. If you get lucky and find a Six that doesn't need to be rebuilt right now, then you could do the swaps for about the same amount of money (assuming a very nice Jake-built four). However, with the four, you'd have a brand-new engine that would likely last you 100K miles before needing attention. With the Six, you'd have an engine that would probably give you no more than 50K miles before requiring a $10K rebuild. It could easily give you only 1K miles before needing that money spent. Roll of the dice.

Comparing like for like, a fresh SC engine with all of the conversion parts is going to run you $15-20K. A new Jake-made 2.3-2.4 four will cost you half that, even with Nickies and ceramic coated everything. Both will live longer than is practical to worry about (how long will it take you to run up 100K miles on either engine?). Granted, the SC will make more power (and certainly more torque), but it's also twice as much.

[olav]

QUOTE (lapuwali @ Aug 16 2005, 09:00 AM)

For purely street use, one consideration against the six is noise. That big fan pointing directly at the firewall is LOUD. I had relatively little intake noise and little exhaust noise on my 2.4 CIS Six, yet you still had to shout at the passenger at freeway speeds because of the fan noise. For a weekend toy, this is tolerable. For a regularly driven car, however, it gets very tiring. With K&N filtered Webers, you have even more noise.

Well, you can always get those walkie talkie things for motorcycles to communicate to the passenger... (IMG:http://www.914world.com/bbs2/html/emoticons/biggrin.gif)

[maxwelj]

I guess one man's noise is another man's music.... Those webers sucking air and the rattle of the chains are still music to my ears.. Radio? we don't need no stinkin' radio!

[Ferg]

QUOTE (maxwelj @ Aug 16 2005, 09:15 AM)

I guess one man's noise is another man's music.... Those webers sucking air and the rattle of the chains are still music to my ears.. Radio? we don't need no stinkin' radio!

Agreed! no radio! set off a car alarm last night with my exhaust (IMG:http://www.914world.com/bbs2/html/emoticons/blink.gif) .
Ferg

[john rogers]

As a strict cost comparison, the next time you are in San Diego you are welcome to stop buy and you can total up the reciepts for the four cylinder and for the six cylinder engines over the years. I am guessing that the four cost 3 times in maintenance over the same period of time that the six does? Besides, it is NOT the engine, it is the driver that wins the races!

[redshift]

QUOTE (airsix @ Aug 16 2005, 12:37 PM)

-Ben 'gimme unbiassed objective data'  M.

There is a Birdite that will back up claims of sub 300k/m 3.0 motors still pulling cars around. (IMG:http://www.914world.com/bbs2/html/emoticons/rolleyes.gif) I won't mention names, because only the worst kind of troublemaker, would force Dxxx Dxxxxxxx to get into this conversation.

(IMG:http://www.914world.com/bbs2/html/emoticons/unsure.gif) ooops...

Given a budget of $10k, a /6 will get you a -bunch more performance- that you can count on being there... in 30k miles, when the HiPo/4 needs head work, to get the boom-boom back, and at 60k, when the HiPo/4 needs head work, to get the boom-boom back... and at 90k, when you are freshening the heads in the HiPo/4 to get the boom-boom back, that won't come back, because you need a new bottom end...

A normally functioning 3.0/6 puts out more power than you can get out of a HiPo /4.

It's unfair, really. We are talking about built motors, against stock here.. stock vs stock leans even more to the /6.

It's ok to love something different than everyone else, remember before you blast me, I went out of my way, to buy a /4, when I could have had a /6 for about $10.00 more. I like the sound of a fresh /4, when it isn't grenading.

(IMG:http://www.914world.com/bbs2/html/emoticons/smile.gif)

My opinion has been paid for, many times over.

And James, I think you are a little high on what a /6 costs, and apparently quite low on what a real performace /4 costs... 3.0/6, is a core + around 7500, vs about 3/4ths the HP from a $15k /4.

M