Well My Race Engine Is Pretty Much Done Now

[jluetjen]

It's been almost 7 years since a 2.4TK engine with a bad knock was dropped off at my house. This past weekend I finally put the carbs on and consider the engine pretty much done. The engine is intended for SCCA E-Prod competition so it built to those rules, which is why you won't see any twin-plugs or 46 mm carbs. The big performance limits of the rules are that you can't machine the heads to allow twin plugging, and you need to use 40 mm carbs with 34 mm venturis or smaller. The venturi sizes really limit the engine's air flow and prevent 8500 RPM engines. I expect the engine to generate peak HP around 7000 RPM and so I tried to optimize the engine to that fact.







As you can see, my budget didn't allow me to make a real looker, but than in the SCCA sometimes it's helpful not to appear like you have a huge budget -- which I don't. I chose to focus more of my resources and money on the inside of the motor rather than the outside. As far as the insides are concerned, it's a 2.2 with a 1 mm overbore (~2.3), DC80 cams and ~10.5:1 CR and will run only on race fuel. For version 1.0 of the engine I didn't even bother porting the 2.2S heads since they were good for 210 HP+ in the 2.7RS. Given the smaller capacity of my engine they should work fine given that in E-Prod most of the cars seem to be making about 220-230 HP. I've got some SSI's that I'm going to have modified to work with "phase-9" style mufflers. Along with using a standard air-box (once again -- it was good for more than 230 HP in a 3.0 RS) I hope that the car will meet the SCCA sound reg's which require the car to be less than 103 dBa at 50 feet from the edge of the track. The final piece that you don't see here will be a fully mapped ignition system.

The strategy for the engine build was pretty much as has been discussed here on Pelican's engine building BBS. Thanks to Matt Blast at Eurometrix who did the carbs, Mark Nadler at Exotech who did the heads and Walt at Competition Engineering who did the case and Zindt at Lindskog Balancing who balanced up all of the moving pieces.

This winter the objective will be to build up the transaxle (as well as fix the whiny gears in my street transaxle). Than I'll have to start work on a chassis to put the engine into. It's good that E-Prod is one of the more highly subscribed classes in the SCCA, so there's a good chance that the class will still be there by the time that I finish the project. Ah, but the joy of the project is in doing it as opposed to completing it!

[stownsen914]

Cool, sounds like a fun project ... is this going in a 911 or 914?

As for sound, you should be good with Phase 9s. You'll probably be in the mid to upper 90 db range with those.

Scott

[jluetjen]

It's for a 911. In E-Prod 914's are limited to 2.0 liters with 2.0 heads.

[Jeff Alton]

Looks good John, congrats on getting it finished!

Cheers

[304065]

John-- NICE! It must feel so good to have a project come together!

Hey, it's what's INSIDE that counts. Show up with a bunch of flashy braided stainless hoses, slick powdercoat and a polished case, pretty soon the scruitineers start tearing things apart looking for the GT3 Titanium Rods! A nice touch would have been to use a yellow 911T shroud!

I think it's cool that you are using a stock airbox and SSI. I would be interested to see the dyno sheet for this engine-- my guess is you may get a pickup using the stock setup versus open stacks. There is a cool fabspeed carbon-fiber air inlet available ($175) but I bet you could fab something that looks like the SC/RS in an hour or so. I just use a chopped-off schnorkel, but I race in the rain a lot

Speaking of racing in the rain I am pleased to see you will retain stock defrost capability-- it's worth a couple seconds a lap if you can actually SEE the track ahead. The California guys probably don't have the same problem we do.

Again, Congratulations, nice job.

[jluetjen]

Originally Posted by 304065

A nice touch would have been to use a yellow 911T shroud!

The black shroud is a T shroud.

[ninesixfour]

7 years? You sure are perseverant! How many hours do you expect out of it before a re-fresh?

[jluetjen]

There was lots of dead time in that 7 years. Some of it because I was saving up to order parts. A lot of the big dollar items (crankcase R&R, heads, etc) are front-loading in the project, so they were spaced out so as to not bankrupt the budget. Most of the long block actual assembly I did two winters ago, with last winter distracted on issues with my 911 itself.

Unfortunately I don't have time and the financial commitment to spend on the project like I did when I was a bachelor. Nowadays my time and financial commitments start with my wife and kids, and my job. My Porsche and any racing projects have to get in line behind that. This is why I've chosen to take a different, un-hurried approach. In the old days it would be a total thrash to get everything done on the car prior to heading to the track. Now I focus on doing a good job in the time that I have, and the car will be ready when the car is ready.

[jpnovak]

Bravo John! Great to see the project finished. I can't wait to hear stories of the track outings.