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Jetting + General advice for my 2.7L Type 4

Posted: Tue Jul 10, 2018 9:57 pm
by rioprelude
I purchased a 2.7L Type4 engine from Jakob @ GetBackOnTrack about 4 years ago, and I'm finally ready to install it in my project vehicle. I wanted to verify the jetting, ignition, and steps to get it running after sitting for so long.
Engine Specs:
DPR 78mm x 105mm Duetz Cylinders w/ JE Pistons
Webcam 86C
AMC Heads 46/38 Valves + dual springs w/ matching manifolds
Full flow Oil + Electric cooler (already in car w/ type 1 engine)
Horizontal 911 cooling

Carb Specs:
Rebuilt Dellorto DRLA 48mm carbs from BlackLine Racing:
Air: 220,
Main: 200,
Idle: .75,
Venturi: 40mm,
E-Tube: #2

MSD Distributer/Blaster Coil/6A Ignition (already in the car w/ the type 1 engine)

Type 4 Sidewinder 1 5/8" from Tiger @ A-1 Performance w/ O-2 sensor bung

1. Does the jetting seem close?
2. Do you think I need to replace the valve springs from sitting so long?
3. I remember seeing an old post about building oil pressure by manually spinning the pump before trying to crank?


Re: Jetting + General advice for my 2.7L Type 4

Posted: Wed Jul 11, 2018 8:21 am
by wreck
I've a similar set up , 103x78 , scat C55 with 48 trijet Dellortos but with a bigger header , I'm still trying to find the right jet combination , right now I've 40mm vents 185 mains 195 airs with 45 enrichment jets . I've run 42mm vents with 205 mains with 195 airs with the enrichment jets blocked off ,(that had a lean midrange going from high 11's to mid 14's back to low 12s on a dyno run) all with the .2 emulsion .I've ordered .3 emulsions and will be trailing those. I'm down to a 63 idle jet with gives 13 to 1 cruise on the progression circuit .I found 75 idles way to rich and the engine would load up at idle .
I'd be inclined to remove the springs and at least get them checked for spring pressure . I spun the motor over on the starter with no plugs in it to get oil pressure , then fired it up .

Re: Jetting + General advice for my 2.7L Type 4

Posted: Wed Jul 11, 2018 9:16 am
by Steve Arndt
Jakob is very active on his personal and business pages on facebook. Ask his advice on the springs. I would say you are fine to use them as is as a guess. Get his advice on break in oil / additives as well. That is critical.

Re: Jetting + General advice for my 2.7L Type 4

Posted: Wed Jul 11, 2018 9:42 am
by rioprelude
@Wreck, I'll buy some additional jets and pick up an air/fuel ratio gauge to monitor the mixture ratio.

@Steve: I did ping him on Facebook, and he though the springs would be ok, but mentioned building oil pressure to protect the bearings.

Appreciate the feedback, just wanted to get everyone's input, since this is a pretty active forum.


Re: Jetting + General advice for my 2.7L Type 4

Posted: Sun Sep 09, 2018 2:45 pm
by rioprelude
I made some progress this week. I was able to install the CSP oil filter block off, oil cooler adapter w/ AN8 fittings, oil filler, and the KEP flywheel/clutch/pressure plate.

I was able to get the engine installed, after making the rear valence removable. It was so tight before, it literally got hung in the engine compartment, even with the cooling system removed.

I have the exhaust/carbs mocked up. I need to setup the linkage, and try to center the copper gaskets better between the heads and the exhaust stubs. I saw a few threads mention Locktite 518.

I was able to fill it up with oil, but have a pretty bad leak around one of the push rod seals. Found a thread showing how to remove the tube/seals w/o removing the head, but hoping I might be able to ignore for now, and fix later.

Since this is a 911 fan with no oil cooler, I was planning to use my existing external oil filter (oem blocked w/ cover) and single setrab cooler installed over the axle. I was planning to connect the oil lines to the CSP oil cooler adapter, but saw a few other recommendations (oil filter input, return to galley in the case), and the oil gallies are tapped.
I'm thinking at this point, I will finish plumbing the oil filter/cooler, get the jetting adjusted based on the previous posts, build oil pressure, and get it fired up for a few minutes, look at the oil temps and AFR, etc. I can address the plumbing and cooling later.

Does anyone have experience with a similar setup w/ external only oil cooling? The single Setrab cooler is angled vertically, so I could add a duct/deflector to help, or upgrade to a dual version. I found a few threads, saying upfront is best, but was hoping to avoid it if possible.

Re: Jetting + General advice for my 2.7L Type 4

Posted: Sun Sep 09, 2018 4:39 pm
by wreck
Gabbi underneath . .jpg

I use 2 coolers either side of the gearbox , get a Mocal thermostat controlled sandwich block that goes between the oil filter and oil filter mount .I've a thermoswitch for the fans. I live in a semi tropical environment that gets to 35C in summer and it works fine . gets up to temp , then the fans start cycling in and out regulations the temp between 70-90C .

The pushrod tube can be done with the heads in place in the car . Ray mentioned on another post that there is a VW tool to grab them internally and extract them . I've carefully twisted them to get them moving then pulled them out using pliers which is not the best method . On my 2.6 I just used engine oil to lube the O ring seals and haven't had a leak .

Re: Jetting + General advice for my 2.7L Type 4

Posted: Sun Sep 09, 2018 5:19 pm
by rioprelude
Thanks again! I will look into getting another Setrab unit. So you like the Mocal sandwich block at the oil filter vs. tapping to the stock oil cooler inlet/outlets with a CSP Adapter? I currently have my stock oil filter blocked off, but can easily revert it.

Is that a 1 3/4" exhaust? I let Tiger @ A-1 talk me into a 1 5/8", but I'm worried it might be too small!

Re: Jetting + General advice for my 2.7L Type 4

Posted: Mon Sep 10, 2018 2:40 am
by wreck
I like the Mocal , another benefit is oil pressure straight away , the coolers will bleed a bit back to the sump and the Mocal allows a bit of oil to flow through the system when shut so it's sort of self bleeding . I've plugged the small bypass valve in the filter housing (I do frequent filter changes so don't need it) .
The exhaust is DIY , stepped 1 3/4 to 1 7/8 at the collector with 2 1/2" mufflers .I've a good friend with a 4.040in X 78 ,he has 1 5/8 primaries and still makes 170WHP at 5500 with a type 4 fan and hydraulic cam .

Re: Jetting + General advice for my 2.7L Type 4

Posted: Mon Sep 10, 2018 8:56 am
by Steve Arndt
Try it first with the single Setrab before going dual. They work pretty darn well.

Re: Jetting + General advice for my 2.7L Type 4

Posted: Mon Sep 10, 2018 12:49 pm
by NextGen
I love the Horizontal Design. That is going to be an amazing Ghia. I did not realize Horizontal fan housings do not have an oil cooler.

Re: Jetting + General advice for my 2.7L Type 4

Posted: Wed Sep 12, 2018 5:02 pm
by rioprelude
Thanks guys. I'm slowly getting parts in, and hope to make some progress next week.

Re: Jetting + General advice for my 2.7L Type 4

Posted: Fri Sep 14, 2018 7:40 pm
by Bobby74
Just wanted to say that's a cool and unique build! I don't see a lot of 911 horizontal shrouds being used. I bet you will get people asking if its a Corvair engine :) Sounds like it will be a nice combo also.

I would leave the jetting and valve springs alone, until you get a chance to run the engine and see how it performs.
There's been many of engines that have been 'mothballed' (fogging spray) for decades and did not need much more than having the oil system primed and fresh fuel.

A good way to prime the oil system (on an engine that has been sitting) is:

Remove spark plugs.
Remove rockers to prevent unwanted stress and wiping whats left of the cam lube off.
Squirt 'fogging spray' or a light machine oil into the cylinders.
Remove oil pressure switch/sender.
Squirt engine oil into the oil pressure switch galley/hole and lube the rockers while they are out.
Crank engine until oil squirts out of pressure switch hole.
Install pressure switch/sender.
Crank until oil light goes out or until oil pressure (5-10lbs) is achieved.
Install rockers/pushrods, also check lash.
Install spark plugs.
Fire engine and watch oil pressure immediately.
Follow cam break-in procedure if it has not been broken in already!

Good luck and have fun! :)