8000 rpm/300 bhp 3.2 rebuild

[Gary71]

From what I know of the JDM Honda it has an 11.7:1 compression ratio and a high lift cam profile that if asked to idle at less than 2k would simply refuse…power band is 6k to 9k

Cams will dictate where the power is developed, and as you are doing this to reduce gear changes that’s what I’d put the research into

[MikeB]

If you look at history, 1 litre 2 valve race engines (BMC A Series and Ford 105E) made in excess of 100 hp on basic carbs and ignition. So S 3.2 litre Porsche should be able to make the same, you’d think. Yet the 3.0 SCRS engine, which I imagine would be the sort of motor profile you are looking at, was apparently 255hp at 7000 rpm.

What is the best a 3 litre N/A 911 race engine made?

[neilbardsley]

Graham's bgt all the gear now. I hope he proves every one wrong.

If I'm correct part of his motivation is to have to do less gear changes so hence the 8k target. What happens if the power band width remains static but just moved higher?

Sent from my M2004J19C using Tapatalk

[Hugo 356]

What is the best a 3 litre N/A 911 race engine made?

The 3 litre RSR was chucking out 330 bhp @ 8k in 1974. With 47 years of development on his side Graham can find 300. This build's gonna be a corker

[911hillclimber]

Gearbox:
The 915 was designed for rear (911) and Mid (914-6) so to do the mid engine installation you simply flip the crown wheel over from the 911 side to the 914-6 side.
The advantage also is the side thrust of the CWP design is taken by the solid cast side of the box, not the fragile bolted-on side cover.

Power:
Neil has it spot on. I need to reduce gear changes on the track. (hence adding the WEVO internal gate device.
300 bhp? Maybe not, maybe so, but it would be a nice by-product. . Time will tell.
I do not think throttle bodies will give much over the carbs on WOT.

Cams:
several people on IB and other places such as Connaught Engines and the USA all point to GE60 cams originated by Bruce Anderson.
Seems to give the same characteristics in a 3.2 as the E cams do in a 2.4.
The GE80 is wilder but could be cammier so to speak, and a delay in getting going if 'off' cam would be disaster on a hill.

A lot of hillclimbing is down to saving 1/10 of a second, but everywhere. Every gear change, braking point etc.

[sladey]

Are you porting the heads Graham? Mr perkles on IB did this and I think got good results on a 3.0

[RobFrost]

Are you porting the heads Graham? Mr perkles on IB did this and I think got good results on a 3.0

FWIW I think it's important to understand precisely what "good results" means. A 911E is faster to 60 than a 911S despite the lower headline horsepower figure, because its power band is wider. Generally, and tell me if you think I'm wrong, but ported heads will increase peak power but are likely to narrow the range of revs in which power is delivered - which is the opposite of what Graham's after.

[hot66]

Are you porting the heads Graham? Mr perkles on IB did this and I think got good results on a 3.0

FWIW I think it's important to understand precisely what "good results" means. A 911E is faster to 60 than a 911S despite the lower headline horsepower figure, because its power band is wider. Generally, and tell me if you think I'm wrong, but ported heads will increase peak power but are likely to narrow the range of revs in which power is delivered - which is the opposite of what Graham's after.

Not necessarily. Depends if you are opening the ports up for increase airflow ( which will be of benefit at the higher rpms with aggressive cams ) or just smoothing and matching inlet ports to intake manifolds etc ( more efficient airflow)

An engine is just a big air pump at the end of the day and you want the correct amount of air to flow as well as it can through it . Too big ports and at low revs you get low air velocity which isn’t ideal …. Too small ports and they become a restriction to air flow

911 heads are pretty efficient to start with though so you don’t tend to see massive amount of work done to them .. unlike vw type1 motors where the heads usually have significant work done to ports / valves . This is where the question crops up though of wether stock sized valves and ports can flow enough air for 8000rpm …you can build an engine to cope with those revs, but is the power going to drop off due to airflow restrictions or is it going to be fine ? Think that’s the question graham has been trying to find an answer to

[911hillclimber]

Heads will remain as is, stock.
Not going into the DEEP COST PIT of chasing a few bhp.
Similarly, the boat tailing of the cases and the barrels, maybe 10 bhp. Most rolling roads runs are +/- at least that on the same day, even the same hour.

No, keeping this job as simple as can be.

Picked at the engine a bit more for an hour, very busy weekend, Bike show yesterday, Bicester today.

Exposing the flat fan, hidden for the last 5 years.

The fan shrouds hand made by Crispin Manners are fabulous. must have taken hours and hours



Custom made cross bean with drive and angle drive box for the fan driven off the custom alternator pully belt



A better view of same maybe



Quickly getting to the point of until the 911 goes to storage on 1 Nov I can't do much more due to space.

[yoda]

What a great project and the car will be a rocket ship. Look forward to seeing this build.

[911hillclimber]

Thank you, hope you are right!

Quiet now until the 911 is gone away unless I can get it in storage early.
Lots to clean and paint/touch up, but really the next stage is the box off and the engine on it's stand, dismantle and get the heads machined.

2 months before parts from the USA arrive....

Jan/Feb/March will be hard going, but FUN!

If I can get 300 bhp, the car will be about 535 bhp/ ton which is another kind of fun......

However, it did once have 500 bhp

[Cortina]

I can see LOTS of potential weight saving in those mounting brackets ..... every gram helps !!

[911hillclimber]

Yes, the car weighs in as 62% rear, 38% front on corner weighting, very 911...

[911hillclimber]

Stuart Brownsey will not machine the heads due to fear of cracking off the cooling fins around the heat sensor.

So, awaiting a reply from Fiennes Performance.

Nobody so far wants to do it, though I base that on zero responses from them even using their own Contact facilities.

Why do specialists give you an official contact system and not respond to it when used?

[RobFrost]

Nobody so far wants to do it...

What is it you want doing - twin spark? Pretty sure I saw that service advertised recently but it eludes me precisely where. Will wrack my brains.