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My 1971 911T 2.8 Engine Build
Figured I'd post my ongoing build here... will update later with some pictures and some initial specs. Cases are due back from machine work in about a week, about 1/2 of the major mechanicals are in hand, rest on order as of today.
I'd posted a few months back on ideas, and have settled on a, probably mostly non-traditional approach to the engine build on my 71T. No carbs or MFI here. And most of the rotational assemblies will be from modern car designs. I purchased a core 77 7R in very nice condition, will use many of the take offs to refresh the 77 7R with carbs currently in the car for a future project... !?!? Very much appreciate all the knowledge here to gain ideas as I worked with the builder I'm using. General philosophy: 7R mag case, street focused, happy at sea level to 7k ft, modern/light/low friction rotational assemblies, modern engine controls to deal with how and where I drive the car. Basically, classic engine, keep many of the classic looks, but, modern 'insides'. I want it fun around town, in the hills, with good power, and, no carb annoyances as I'll drive it from sea level to the top of Angeles Crest and I want it consistent, always. My car is essentially a sleeper, innocent looking 71T with a full refresh and updated sportier chassis setup. No flares, she's skinny and staying that way. May squeeze a 7R with a 215 out back. 911/01 trans is fresh with various upgrades already done, will be installing an LSD. Here's the basic build spec: Case - 1977 7R - clean core with all the tricks done by Ollies, opened up to support 2.8L 996 Turbo oil pump Custom crank - allows use of GT3 TI rods w/ modern bearings GT3 Titanium rods Custom CP pistons 2.8L. Custom light design will be based on newer pistons spec Custom / modern type rings and ring design on piston Custom light pin / coated Compression measured to 10.5:1 Nickies cylinders - with custom boss to attach 993 type knock sensors (1 per bank) Heads fully re-worked by xtreme. All the tricks, dual plug, TI bits, porting etc. Billet DLC rockers Something around the DC60 cam profile (this we may tweak...). But my desire is decent drivability, don't want it super peaky, Power from 4.5k+ and rev to ... 8k-ish. GT3 intermediate gear Rasant induction, throttle bodies, high rise ITB intake Motec M1 with dual lambda O2/knock, and all the sensors necessary for modern engine management Rasant custom wiring harness for all sensors Fiberglass tins All cosmetics done done - builder going to surprise me :-) ....and some tears as I write the checks and question my judgement for spending this $ on a mag case engine... The orange one, not the italian! http://forums.pelicanparts.com/uploa...1577465082.jpg |
Really nice looking car, the orange one!
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As the owner of a '71T Targra I'll be watching your build closely. I hope it meets and exceeds all expectations.
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forged Crank (someone here may recognize this... )
ITB stacks and EFI throttle bodies (similar design to this ) Forged rockers heads getting 'built up' for a LOT of machine work GT3 TI rods, weight comparison to stock the back side of the pistons, these are not the actual pistons but designs will share similarities. light and strong http://forums.pelicanparts.com/uploa...1577640413.jpg http://forums.pelicanparts.com/uploa...1577558925.jpg http://forums.pelicanparts.com/uploa...1577558925.jpg http://forums.pelicanparts.com/uploa...1577558925.jpg http://forums.pelicanparts.com/uploa...1577558925.jpg http://forums.pelicanparts.com/uploa...1577558925.jpg |
Thanks for posting. This will be interesting to follow.
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Wow. What are you doing to those heads! Love these builds. I have a very similar 2.8L build with ITB EFI (AEM Infinity), same compression as you (JE pistons), Carillo rods, twin plug, 39mm/38mm ports, and am running a DC65 cam. Idle is a bit lumpy at 1100-1200 (with 4-5 degrees timing), but it is otherwise very tame just driving around and revs very well to 8k. I may try a DC40 cam as I feel a DC60 or 65 wants a perhaps bit more static compression to work really well. I think a DC40 will have very close to the same rev range with all the light internal components and head flow anyway. DC40 duration is very close to DC60-65 and I feel like my heads may not be flowing way at the top end what optimizes a DC60-65. It's like I hit a wall for fuel requirements at around 7300-7400, as after that my EFI mapping requires to maintain the a/f ratio I'm going for at WOT that I back off fuel a touch to 8k. I really don't know for sure but will undoubtedly give this a shot to satisfy my curiosity and report back.
DC40 @ 1mm 266/249 .490 lift DC60 271/255 .485 lift DC65 272/258 .508 lift stock 'S' cam 268/240 .455 lift |
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The headwork is basically building up the material to reshape the chamber for the right CC needed based on the piston design... in addition to some reshape, and changing the spark plug sizing, dual plugs, port and polish to spec, and larger valves. Xtreme is doing the work and it's not cheap.... but sill about 1/2 the price a set of their full spec heads!!!???!!! |
Couple pics of the 'donor' as it sits. The engine in the car is nice, 77 2.7, but has #2 with a leaky valve guide so starts to smoke a bit when really warm and at idle... so will need to address that but otherwise the car goes great and runs awesome. So will save this for a 'future' something or other :-)
The last pic is a local car that Rasant build, 3.2L short stroke i believe, with some really nice classic MFI look with EFI added. Won't be exactly like this but something 'similar' but won't be using the factory red stacks... http://forums.pelicanparts.com/uploa...1577640042.jpg http://forums.pelicanparts.com/uploa...1577640042.jpg http://forums.pelicanparts.com/uploa...1577640042.jpg http://forums.pelicanparts.com/uploa...1577640042.jpg |
Sorry for being OT, but this color is gorgeous. What is it? Do you have a paint code?
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The white car is rapid, if it is the same car I was following on the Targa Cali! And, I belive it is!
Funny I am in the middle of a build for my '71T.... bought a 7R case, then an SC motor .... then a 3.2 crank .... and now its mushroomed to a 3.8 build (964? based) motor that was on the TRE shelf! I wanted the Rasant ITBs ..just like the pic, but the 3.8 is running Rothsport ... what works for me! These projects can get out of hand! |
^^ I suspect it is :-)
I really debated the 3L / etc - but I have a 964 hot rod already (that will be getting a 3.9-4L next) and a 997 GT3RS... so i wanted the 71 to have a feel/character of the 'older' cars so trying to keep a limit on the ultimate power, while making drivability better (I hate carbs!) Rothsport is fantastic. I have several buddies running his engines in 964s. Another friend has a Motec 3L in his 72 that he built. |
Spyerx, I agree 100% that was my intention on starting with a 7R case, but I could not resist tempation. My plan is to use next year's Targa Cali as the shakedown run! You should attend!
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Crank balanced.
More pics of pauter dlc rockers Cams dc60... although we may tweak that... Crank balanced Heads getting close to done Case here by end of month Pistons and cylinders about a month out Harness about 6 weeks out http://forums.pelicanparts.com/uploa...1578321525.jpg http://forums.pelicanparts.com/uploa...1578321525.jpg http://forums.pelicanparts.com/uploa...1578321525.jpg http://forums.pelicanparts.com/uploa...1578321525.jpg |
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Fancy liner. What is the wait time for Nickie's to make one with the knock sensor boss?
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LN, this is a 3D CAD drawing... being made now... it's a process lol. From request to delivery? I dunno probably 3mo. EVERYTHING here is a 3mo lead time. :-) That's why I bought a core to build I didn't want 6mo in down time! |
Heads in process .... it’s a LOT of work to rework these.
http://forums.pelicanparts.com/uploa...1578574408.jpg http://forums.pelicanparts.com/uploa...1578574408.jpg http://forums.pelicanparts.com/uploa...1578574408.jpg |
Lots of great detail work on this build.
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Sweet Mary. Love the heads
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Couple updates:
Head work continues. They look AMAZING. So much effort. No pics... Visited Rasant yesterday with the engine builder - Rasant just moved to a new facility about 15 minutes from me - he has some very cool projects going on there. My harness is about 75% done. After taking a look at what was done so far we specified a few more options, adding couple sensors, a block out plug for analog and digital outputs, atmospheric pressure in addition to MAP. We'll be using a motorsport resolution oil pressure sender in the location near the thermostat, temp will be oil and CHT which is custom done on the heads, along with a bunch of other sensors (TPS, fuel pressure, etc etc and dual knock, dual o2). The Motec will control the Tach, oil pressure, and oil temps, which will be able to log everything. Will have Tach updated to a 10k face, no RPM indicator, will use tape for that :-) Will also update the internals to a 3.2 type which has a different signal resolution and easier for Motec to deal with natively w/o a converter box. The dual plug setup is using a compact coil with a separate driver unit. The car will also have an idle air control valve. All of this managed by motec. And will allow once tuned great cold, hot start and drivability. Like a modern car in a 71 :-) The drivability is important as I often take the car from sea level where I live up to 6-7k ft in an afternoon. As stated earlier, the ECU will be a Motec M1 with dual lambda and dual knock options. Oh, also going to talk to North Hollywood Speedo who i'll have do the face, if they can mod the case on the tach to add an extra light for SHIFT and CEL / Oil pressure. :-) All the throttle bodies, trumpets, etc are done and getting anodized now. Anyway, don't estimate the effort on these wiring harnesses, it's EXTENSIVE!!! I forgot to take pics, was too busy talking... |
Very nice! Rasant's Hall crank/cam sensor setup is by far the best and easiest setup on the market.
I also went with a very high quality digital oil pressure sender. The peace of mind compared to the dash gauge readings is substantial. My dash gauge is consistently 15-20% off actual digitally confirmed readings. |
Need to see this one!! Who is the engine builder?
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Update:
heads nearly done Case expected this week or next Pistons in 2 weeks long tail is the cylinders :-( |
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Are the throttle bodies shaped to match the head inlets? Would love to see more of those...
Sent from my Nokia 7.1 using Tapatalk |
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Exhaust ports are an issue we are looking at options as ssi i have are too small... looks like a few good options out there. |
nice heads
I was just at Extreme and saw Bill last week.Cool shop and a nice guy.Who makes the stacks?Fred
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super cool throttle bodies
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https://www.instagram.com/rasantproducts/ We have Andrew at Rasant doing the full induction, ignition, and wiring harness. He does super nice work. Local SoCal manufacturer. The harnesses he makes are fantastic and very fairly prices given the amount of effort, my shop will do harnesses but after seeing these they like what they do. he's done a lot of development on integrating modern sensors and engine management into the older engines. Most of the engines he builds are the 3.0-3.8 (SC to 993) models. Offers options like a full plenum style induction, stacks, etc with several different options. Also lots of options for engine control/management (motec, AEM) and spark control using various modern coil on plug options. We'll have his stacks, throttle bodies, throttle linkages, all wiring, fuel injection, cam/crank sensors, spark, etc integrated to the build. Engine control will be Motec M1. Quote:
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Delays... delays...
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Virus delays!!!
Heads? hmm.... Everything else is in hand... ready for assembly. |
We have heads! So everything is in hand, all the various measurement, CC, etc started this week. Have a bunch of hardware at plate. All inductions / electronics are done and will show up when the plating is finished. All other 'small' bits are in hand, we're replacing everything.
Here are a few pics of the finished components: Case fully machined and prepared by Ollies with provisions for shuffle pins 996 Turbo oil pump 6 bolt crank by Supertec, allows use of GT3 TI rods Heads reworked by Xtreme, ported, polished, dual plugs, etc CP Pistons with a modern, lightweight design and ring stack 10.5:1 target compression, pocketed for big cams Cylinders by LN, with provision for 993 style knock sensor, we will run dual knock sensors with MotecM1 Displacement: 2.8L DLC coated pins and gt3 TI rod (ugh having issues uploading pics will post later) |
That’s a great engine you’re building. I’d be interested in learning about your CP piston design if it is a flatter type piston and they’re weight. Also, curious what brand rings and tension you’re going with.
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Man this is going to be a screamer- what's the redline?
Pete |
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Around 8k? We'll see. |
Thanks for posting pics of pistons and heads. Looks good. That answers my question about piston shape and head combustion chamber.
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The overall idea here was a modern 'insides' and engine controls/management. So light, strong, modern friction surfaces, and modern controls. My desire is this runs and behaves just like my 964 :-) It SHOULD be better! Saturday ran that car up Angeles Crest Highway which gets up over 7100ft and the carbs just get CRANKY up there... it's ON or OFF. Sea level it's great. The 964 drives like it should.... |
piston
The piston looks great.How much does it weigh with out the pin?What size valves did Bill put in?Great looking build.Fred
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