74S to RS+ spec engine build

[al lkosmal]

I recently received a 74S engine. Very cool engine with early CIS....runs great, great leak down (4-6% on all cylinders)......however, I have no respect and therefore it must be subjected to semi-serious power producing mods................and so it begins....

video of it running.....
https://www.youtube.com/watch?v=I1QQVyT0We8


off of the test stand and moved to the engine/rebuild stand



Can you say "Triangle of death".....



more to come.....I'm thinking RS+ spec:

EFI/ITBs (surprise)
9.5:1 JEs
E-cams
headers
sport muffler
For ECU I am thinking MS3 and using it to control....
Sequential Injection/ Ignition
COPs

I can then compare it to the AEM Infinity that I used for my last build.
stay tuned....

[stf996]

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[Charles Freeborn]

Not to split hairs, but that air filter snorkel is different than mine. Looks like a later WUR too (can't really tell from photos) so that would make it a '75 or later? What say serial number search?
When p/c's come off, if they're still within spec, I may be interested in them.
-C

[unclebilly]

Al, I did this a few years ago and plan on bringing this car on drive #2 this year.

I ran mod s cams and a RS distributor curve with MSD but with Webers. My cylinders are shimmed to 9.8:1 compression.

You will love it.

[75 911s]

Originally Posted by Charles Freeborn

Not to split hairs, but that air filter snorkel is different than mine. Looks like a later WUR too (can't really tell from photos) so that would make it a '75 or later? What say serial number search?
When p/c's come off, if they're still within spec, I may be interested in them.
-C

My 75 snorkel is elongated. Maybe its a ROW 74 CIS? I'm curious to know pros/cons of swapping ROW CIS setups to US engines. Is this how I would make my 2.7 165hp back up to the 175 ROW rated HP? I know the intake runners are larger...

[al lkosmal]

Sorry...good catch.....1st pic I posted is not correct, but from a 77S I just sold. I build and rebuild....and i have many pix and inserted the incorrect one.

I deleted the 1st pic I previously posted and here's the 74 engine on my test stand..........

[al lkosmal]

Originally Posted by Charles Freeborn

Not to split hairs, but that air filter snorkel is different than mine. Looks like a later WUR too (can't really tell from photos) so that would make it a '75 or later? What say serial number search?
When p/c's come off, if they're still within spec, I may be interested in them.
-C

Charles,
Greetings.....posted the wrong pic initially. i've now fixed that problem....too many engines...and I'm easily confused.

I had a local, with a 74S, stop by to see the engine run and he has already called dibs on the parts, but if you are interested, you are 2nd in line.

regards,
al

[al lkosmal]

Originally Posted by 75 911s

My 75 snorkel is elongated. Maybe its a ROW 74 CIS? I'm curious to know pros/cons of swapping ROW CIS setups to US engines. Is this how I would make my 2.7 165hp back up to the 175 ROW rated HP? I know the intake runners are larger...

duane,
My first pic was incorrect and from a 77S I sold last week....I fixed that with some new pix.

Regarding the 165 vs. 175 HP, I believe that the biggest difference is the early heat exchanger/headers vs. the later, more restrictive exhaust. Install SSIs or headers and you are there.

regards,
al

[al lkosmal]

Originally Posted by unclebilly

Al, I did this a few years ago and plan on bringing this car on drive #2 this year.

I ran mod s cams and a RS distributor curve with MSD but with Webers. My cylinders are shimmed to 9.8:1 compression.

You will love it.

Unclebilly.........I've built quite a few 2.7s to this RS+ spec...it is one of my favorite canyon carver engines to build............

this is a recent 2.7 I built

https://www.youtube.com/watch?v=EWB99lddFew

works well with 3.0s too...

https://www.youtube.com/watch?v=Ig-paaLh2KY

[prebordao]

Originally Posted by al lkosmal

more to come.....I'm thinking RS+ spec:

EFI/ITBs (surprise)
9.5:1 JEs
E-cams
headers
sport muffler
For ECU I am thinking MS3 and using it to control....
Sequential Injection/ Ignition
COPs

Hi Al, this setup is good for how much Hp ? 200 ?
Also, when changing to 9.5 JEs, can you keep your existing Cylinders ?

[Charles Freeborn]

Originally Posted by al lkosmal

Charles,
Greetings.....posted the wrong pic initially. i've now fixed that problem....too many engines...and I'm easily confused.

I had a local, with a 74S, stop by to see the engine run and he has already called dibs on the parts, but if you are interested, you are 2nd in line.

regards,
al

Cool. Thanks.
-C

[Trackrash]

Originally Posted by al lkosmal

I recently received a 74S engine. Very cool engine with early CIS....runs great, great leak down (4-6% on all cylinders)......however, I have no respect and therefore it must be subjected to semi-serious power producing mods................and so it begins....

more to come.....I'm thinking RS+ spec:

EFI/ITBs (surprise)
9.5:1 JEs
E-cams
headers
sport muffler
For ECU I am thinking MS3 and using it to control....
Sequential Injection/ Ignition
COPs

I can then compare it to the AEM Infinity that I used for my last build.
stay tuned....

I mean, since you are going ITBs, why not...
Dual plugs?
10:1 CR?
93 or 94 bore? Making it a 2,8 or 2,9. (unless the cylinders are perfect Mahles of course)
S cams. (E cams won't be enough, IMO)

Sounds like a great build and I am looking forward to your progress.

[al lkosmal]

The tear down is progressing.....always nice to see the rocker feet looking like new and the cams in really good shape.........Nikasil cylinders still showing the x-hatching, etc.

regards,

al

[al lkosmal]

Originally Posted by Trackrash

I mean, since you are going ITBs, why not...
Dual plugs?
10:1 CR?
93 or 94 bore? Making it a 2,8 or 2,9. (unless the cylinders are perfect Mahles of course)
S cams. (E cams won't be enough, IMO)

Sounds like a great build and I am looking forward to your progress.

Thanks...i have built several 2.7s using this recipe and it makes a great running, dependable, hi-po street/canyon carver engine. It is basically an RS spec, but with higher CR and EFI/ITBs that allows you to take advantage of the modern engine management/ignition/fuel tuning. This RS+ combo does work great with S-cams, but my preference is E-cams for an engine that not only spools up fast, but provides lots of low down grunt. Also, I intentionally keep it at 9.5:1...or at least less than 10.5:1 because, unless your goal is ultimate HP, cost no object, you gain very little for the considerable cost related to that CR increase over 9.5:1 (cost of dual plugging, etc) Same for 2.8 or 2.9 mods in my opinion. I.E......I believe that for my build , the $/HP ratio is better...............the rest is definitely very cool,I like it too........ but farther down the slippery slope, cost no object path.

regards,
al

[al lkosmal]

Originally Posted by unclebilly

Al, I did this a few years ago and plan on bringing this car on drive #2 this year.

I ran mod s cams and a RS distributor curve with MSD but with Webers. My cylinders are shimmed to 9.8:1 compression.

You will love it.

what pistons did you use to get to 9.8:1 by shimming....10.5:1 JEs?

[al lkosmal]

[lvporschepilot]

A single plug ITB 2.7 engine with these cams (and 38-39mm intake ports, and 46mm ITBs) should be solid for around 220 at the wheels or 245-250 crank. Great builds

[prebordao]

Al, what's the size of the Speed triple ITB's ? I can't recall...

[Trackrash]

Who is doing all the case work?

I would love to see all the details.

[al lkosmal]

Originally Posted by prebordao

Al, what's the size of the Speed triple ITB's ? I can't recall...

Sorry for the delay......I got sidetracked with commitments on customer engines....but I am back on it today.

The Speed Triple ITBs are tapered. 43.5mm at the top, tapered down to approx 40mm (slightly ovaled) at the bottom.

regards,
al