Show us your "old school go faster" trick for your engine!

[Aircooled4evr]

I'm preparing my engine for a complete rebuild, and incorporating "sensible" help for it to go faster
And it might be cool to see what you have of knowledge and ideas!
I'm not looking for tuning bits, but what you can improve yourself.

I've smoothed the block out for a few more HP.



Lightent the connecting rods for the few extra reefs.


Modified the heads for dual ignition and polished the combustion chamber and exhaust, for less heat absorption.


Haven't bought my high compression pistons yet, but expect to polish the piston crown for a mirror finish.

But there are many more options out there ... tell pleace! and pictures!

[Aircooled4evr]

here's the block waiting ...

[darrin]

no replacement for displacement -- if you're increasing compression with new pistons, have your cylinders bored/replated at the same time --

[Sboxin]

Originally Posted by darrin

no replacement for displacement -- if you're increasing compression with new pistons, have your cylinders bored/replated at the same time --

Yep . . . 3.6L --> 3.8L (by EBS)
And . . . 12.5 CR . . . (EBS)
And . . . WebCams 20-21 . . .
Edit: 8 years racing and only one minor refresh . . . 915 trans has had 2 rebuilds . . . Mads: beautiful engine polishing !!
Regards,
Roy T

[icarp]

Make sure all your combustion chambers are the same to >.5cc or better.
It looks like you are doing a very nice job . If I were you I would not exceed 10.3 CR.
Getting your squish, or quench area, for piston outer edge to the combustion chamber, to 1.0mm it is very important.
Radian valve cut on the seats , ie. 5 angle . Hold the valve seats to the outer most edge of the seat insert, as per porsche specs . Web cam .464-465 if 3.0-3.4 ltr. small port or large ? If you get the cyls re nickied make sure you spec the RA surface finish that the ring Mfg requires . Buy the pistons first, CP is worth the wait , then send one with the cyls to get sized and bored .
Carbs or ITB's? Twin plug will allow for conservative ignition timing 22-26* over all. Valve spring seat pressure all within 1.5 lbs at correct height . Just some ideas !
Ian

[Cajundaddy]

More Displacement, fine tune balance, improve flow, reduce friction, manage heat, precise A/F ratio. All of this makes power to some degree and every motor is a bit different in application. There is often a tradeoff between power and reliability so you need to decide how close to the ragged edge you are willing to go.

[Aircooled4evr]

Thank you icrap
cool advice. my engine will be 100% blue printed! however, I have not heard of 5 angle valve jobs. Thanks so much for that advice! you are right, the valve should be at the extreme end of the valve seat as the porsche runs with long opening and low lift.
It will run with ITB's. Web cam 20/21. Wössner pistons.

Mads

[icarp]

Madds , what is the size of the bore and stroke that you want ?
Why the max moritz pistons ?
I think you will like the web 464-465 better , its a great street cam with lots of everything

[Nick Triesch]

Or you could get a 2018 mustang GT with a 6 speed and 460 horsepower! My point is you can build a super motor but it is still a very old Technology flat six motor. A regular Ford F-150 with the v6 or V8 will blow our little cars away. We can get them in the corners but once there is a straight away..... they are gone!!! Trust me, I know.

[kent olsen]

When I built the 3.0L for my car, 72t, I had already gone thru the 2.4L and a 2.7L. I used to do a lot of track days, not so much anymore, nearing 77, but the car was always a daily driver, now 245,000 miles.

So like you say what will the car be used for?? With the help of a Porsche race engine builder when I lived in Florida this is what I did. 9.5:1 pistons even though with twin plugs I could have gone higher. On the race track horsepower is one thing but torque is what pulls you out of the corners so with the advise of a friend in Seattle, I did like he and had a cam cut with the peak torque lowered to 4500rpm which is where the rpm drops with each shift in my 915 trans. This cam also had the peak horsepower at 6900rpm. So after two days on the engine dyno we had 245hp @ 6900 rpm and 220 ft/lbs of torque @ 4500 rpm. When I had the engine apart I also, at the builders recommendation, had some work done on the crank bearings, don't remember now but that and work on the valve train would allow the engine to turn to 8500 rpm, which I did accidentally once, missing a shift, with no damage. I'm still using Webers, now opened up to 42mm, pretty easy to tune.

I've got 14,000 miles on the engine, it purrs like a kitten until you put your foot in it, then just screams. With my lightened car, 2200 lbs, I'm at about 9:1 power to weight.

[RWebb]

many of the hotrodder tricks for Detroit iron are of little value on a dry sump motor - that is already engineered very well for racing

for each track, you will want to determine how much time you spend near redline

[icarp]

Madds, I have a 73 rs clone with a 3.0 and a mild cam , it works with CIS pistons , I rev this engine to 7,000 rpm 50-60% of the time. It will run 7k in 4th gear and 6700rpm in 5th. The car is light 2260lbs with a sunroof . Cam duration is your friend , not so much lift . JMOP, pulls like a train at 3k and keeps going

[Aircooled4evr]

Originally Posted by Nick Triesch

Or you could get a 2018 mustang GT with a 6 speed and 460 horsepower! My point is you can build a super motor but it is still a very old Technology flat six motor. A regular Ford F-150 with the v6 or V8 will blow our little cars away. We can get them in the corners but once there is a straight away..... they are gone!!! Trust me, I know.

He he... the thing is that i don't care much about "who's the fastest" on the road (any more) ... then i wouldn't have chosen an old vintage car but a modern japanese or italian-something boring! : D Or kept my old car.
No, I'm never going to top my old WV beetle .... close race gearbox, 2.7L type 1. 250+ hp. 328Nm. for 700kg I street raced against motorcycles. never met a street car that could beat it .. NEVER (including big CC Detroit iron with 600+ hp) ((smart ass'nes can occur)) snigger snigger ..

No. i am simply in love with the porsche 911 flat 6 sound! IN LOVE!
If I had been a rich man, I would have bought myself a 1972 S (and tuned it a bit)
But I'm not .. So it turned into a 78 'SC
And I have to admit it was a little too tame in sound and performance .. coming after my wv.
But these days 250hp is plenty for me anyway. as long as the engine is "rev happy" and noisy!

[Aircooled4evr]

Kent Olsen;

So like you say what will the car be used for??

Hello Kent Olsen
I'll probably get to participate in "track days", but that will be rarely I guess.
So it is built more to please me on a mountain pass in Switzerland, or Norway.
A winding country road in Denmark and the like.
So, a powerful and revving engine for the street.

Mads

[Aircooled4evr]

Originally Posted by icarp

Madds , what is the size of the bore and stroke that you want ?
Why the max moritz pistons ?
I think you will like the web 464-465 better , its a great street cam with lots of everything

95 x 70.4 mm 2993 cc 11.3: 1 compression, with web cam 20/21 cams. Because I have two already ... my project IS on a budget, of some sort.
So I hope I can make something strong with the parts I can afford, and what I can do myself. Not because the parts as such need to be cheap, more that I build it over time to find the means.

I'm not quite sure what you mean by Max Moritz pistons?

[darrin]

what's your reasoning behind not boring cylinders to 98mm? no other machine work required, and you're already getting new pistons

Max moritz pistons are wedge-shaped piston design that let's one get away with single plug configurations with 98 or 100mm p/c

[Aircooled4evr]

Originally Posted by icarp

Madds, I have a 73 rs clone with a 3.0 and a mild cam , it works with CIS pistons , I rev this engine to 7,000 rpm 50-60% of the time. It will run 7k in 4th gear and 6700rpm in 5th. The car is light 2260lbs with a sunroof . Cam duration is your friend , not so much lift . JMOP, pulls like a train at 3k and keeps going

Phew... Sounds like my dream car!

[Aircooled4evr]

kent olsen

would you be willing to publish the numbers on your cam so I can compare it to my own 20/21?

Cheers

[icarp]

Madds, sorry I misremembered the name of piston Mfg , Wossner got it .
be careful on comp ratio, measure many times . 9.8-10.3 is best slot . Cutting new pistons that have a comp ratio that is too high will screw up the dome shape in the combustion chamber .
So what parts do you have at this moment and what are you going to buy?
Ian

[Bill Douglas]

Balance the engine by matching rods+pistons to get as even as possible weights. Then there is some formula for having the heavier ones in a particular location. Just something I've heard along the way. Certainly can't do any harm...