My LS1 Conversion 911

shanghai_todd · 03-07-2009, 03:58 PM

First and for Most: I debated if I was going to post about this as I have seen endless flames on users who do conversions with anything other than a Porsche motor. With that said I hope everyone can respect the engineering and creativity of building something unique. We are all car enthusiasts and have a passion for the Porsche and HP, my build will just have a V8…

The Base : 1981 SC with 993 wide body
The Engine: LS1 from a vette
The base Kit: Renegade Hybrids (Great Group of Guys with tons of experience)
Cooling System: Custom made Radiator

Before starting anything no post of an engine removal or rebuild would be complete without the “Look at me I am in the engine bay” picture. This seems to be the Pelican trademark and a great way to put a face to fellow Pelican. So here it is.

shanghai_todd · 03-07-2009, 04:00 PM

The build started with a rebuilt LS1 block that I was able to pickup on fleabay. Since I did not need most of the accessories and was unsure what exhaust system I was going with I decided to purchase the minimum and piece it together how I wanted it.

shanghai_todd · 06:23 PM

After reviewing different intakes and HP gains I went with a typhoon aluminum intake and larger throttle body. Looks very nice and provides a substantial amount of HP but does have its disadvantages in regards to weight. It does sit slightly higher and does weight more over the stock plastic LS1 intake, I would probably not recommend this for anyone else who is considering the swap. It was a very tight fit and makes zero clearance for the throttle body against the back firewall.

For the exhaust I went with the manifold from a ZO6 vette as I really liked the HP gains and found a good deal on Fleabay that someone had modified for a Chevy S10 conversion but did not fit. I had talked it over with Steve at RH and since it had not been done before we were unsure if there would clearance problems. Lucky enough for me that when everything was bolted up and put in the car there were no problems

For sure it will need a good welder and some nice mandrel pipes to be finished but I do not foresee any issues.

shanghai_todd · 03-07-2009, 04:09 PM

Having a 915 tranny and knowing that it would be the weakest link of the build I did go thru and freshen it up with new bearings, syncro’s a billet Wevo side cover and Wevo 1pcs bearing retainer (thanks to Ben at MKexhaust). I was actually surprised once I opened it up how nice the gears and dog teeth were. The PO had stated it was rebuilt when I purchased the car so now I believe him, wish I could have said the same about the motor and not found all the broken head studs

4flyboy · 4flyboy's Garage

Wow! Welcome. No flames from me my curiosity is peaked. Love to see this evolve.
Best of luck,

Scott

BeyGon · 03-07-2009, 04:13 PM

Good luck, I saw a red slantnose with a chevy in it this morning and a 914 with a chevy in it last week. They seemed happy.

shanghai_todd · 06:27 PM

Sorry I have not posted pictures of the engine adapter and tranny coming together.. I am waiting to hear back from RH if they are cool with sharing the information, I understand it may be proprietary information to prevent people from coping their kits.

I will add latter if they are OK with it.

shanghai_todd · 06:29 PM

The radiator is something that I decided to engineer on my own as I do not like the idea of the front mount radiator and having to modify the fuel tank. Since my car is kitted with a 993 turbo body I decided to use the area where an intercooler would go and fabricate a custom radiator the same size. The size and cooling will be the true test but seeing the 2 fans in action and how close they sit to the engine when the trunk is closed I think it should be OK. Filling of the fluid will be the hard part

I may have the filler neck re-welded and re-located if everything works out and the radiator can handle the Florida heat

mca · 03-07-2009, 04:53 PM

Looking forward to the result! I like the creativity. Nice job.

shanghai_todd · 03-07-2009, 05:13 PM

Thanks for the support guys. The work was started in January and I did most of it within 2~3 weeks when I was back in the US. I was able to get most of the engine assembled and mounted into the car while starting some of the routing for the radiator. I had to stop and retun back to Shanghai for the next 2~3 months so I will not be able to finish it up till then.

Facey · Facey's Garage

good start that is forsure !

shanghai_todd · 03-07-2009, 05:21 PM

Here are some pictures of the engine installed into the car. Notice the extra hood shock on the right side of the engine bay. This is to support the added weight of the radiator in the tale. I will need to test it once I get water filled into it and if it can not handle the weight I will add another one on the left side.. Not bad for a $15 dollar upgrade, maybe cheaper than the stock ones

laughac · laughac's Garage

Sublime

Fizzbiz · 03-07-2009, 06:30 PM

Kind of reminds me of the last time I stumbled accross a GREAT porn site, difficult to look away!

FastCarFan · FastCarFan's Garage

Very nice engineering. I am anxious to watch it all come together & to hear how it drives.

I'm curious, what will the LS1 horsepower be compared to the Porsche engine you took out (not sure which engine you had)? How does the weight of the LS1 compare to the original engine? I am guessing that you have raised the center of gravity with the V8 compared to the F6. Is that correct?

Keep posting!

DasBoot · 03-07-2009, 06:46 PM

Nice work! Where you at in FLA?

Roc Doc · 03-07-2009, 06:57 PM

This looks like a fun project. Since Renegade is local, I've visited the shop and drooled at the work they do on site. Real nice folks, and real Porsche enthusiasts, no matter what some folks may say. The last time I was there, they had 914's, 944's, 928's and of course some 911's in progress. These guys love their work.

As far as the rear radiator is concerned, I think you might have some issues with getting enough cooling if you're running it hard, especially if the ambient temps are high. The proof will be in the final testing. I say this from lots of experience with rear mounted radiators in off-road vehicles, and the fact that that "ram-air" effect of a front mounted radiator is clutch in most cases. You can make up for it with oversized radiators, and a real good shrouded fan setup, but it takes some consideration for sure.

And although I can see your point about not wanting to mess with the fuel tank, the front mounted radiator of course helps with weight distribution.

Keep up the good work, I may still go this route some day.

ManaMan · 03-07-2009, 06:57 PM

I like the idea of the radiator, and hope it works for you.

shanghai_todd · 03-07-2009, 07:00 PM

Quote:

Originally Posted by FastCarFan

Very nice engineering. I am anxious to watch it all come together & to hear how it drives.

I'm curious, what will the LS1 horsepower be compared to the Porsche engine you took out (not sure which engine you had)? How does the weight of the LS1 compare to the original engine? I am guessing that you have raised the center of gravity with the V8 compared to the F6. Is that correct?

Keep posting!

Below is taken from Toyjet's website. His car along with the guys from RH all state that the LS1 motor is in fact lighter. Considering that I have a smaller radiator and have traded out the stock starter and other parts for weight reduction I am guessing that my conversion will also be less weight. The truth will be in the ride height when I get her back on the ground, I have 19" wheels and it was a very close fit to the fenders when I had the 3.0SC motor. If it is heavier when I put her on all 4's the fender will hit the tires.

Here is the information from Toyjet

Quote:

The factory 1980 Porsche SC 3.0 liter engine is 178 hp @ 5600 rpm and the torque range is 175 ft/lbs @ 4200rpm. Top speed with stock 1980 porsche engine 139 mph. with 3.88 rear end gears.

The LS1 Corvette engine is 350 cubic inches (5.7 liter), 345 hp @ 5600 rpm, and have a torque range of 350 lb/ft. @ 4400rpm. The LS1 Corvette engine (equipped with a supercharger and 27 inch tall tires at the rear) will enable me to go 184 mph in fourth gear. However, with no roll cage, I limited myself to going 155mph. with a 240lb. witness in the passenger seat.

The quarter mile time ran thus far (11.94sec at 114) mph. was done with a conservative take off at the starting line because of the weak stock axles. (refer to my Custom page to see the actual quarter mile test and tune video of my first successful pass using stock axles at Houston Raceway Park). I now have a set of re-engineered axles that can easily hold up to the challenge of high torque and high horse power.

I weighed the 1980 911 3.0 SC engine and 2000 GM LS1 Corvette engine and this is what I found out: My fully dressed 1980 3.0 Porsche engine ready to install weighed 472 lbs. Factor in the weight of the oil in the 10 quart oil tank mounted at the rear of the vehicle needed to support the 3.0 engine, then your engine plus oil tank weight jumps up to 490. 5 lbs. at the rear of the vehicle.

(One gallon of oil is 7.4 lbs. Ten quarts is 2.5 gallons, 2.5 x 7.4 = 18.5lbs. 18.5 lbs. + 472 lbs. = 490.5 lbs.)

A fully dressed 2000 LS1 Corvette engine ready to install with the engine computer and wire harness, complete exhaust system, engine mounting brackets, AC compressor, alternator, custom water pump adapter, transmission adapter plate and flywheel weighed 434 lbs. This is a rear vehicle weight savings of 56 lbs. over the Porsche 3.0 engine. I did not weigh the above engines with the transaxle or clutch assembly bolted to either engine. These parts would be used for both installations and their weights would obviously cancel

shanghai_todd · 03-07-2009, 07:08 PM

Quote:

Originally Posted by Roc Doc

This looks like a fun project. Since Renegade is local, I've visited the shop and drooled at the work they do on site. Real nice folks, and real Porsche enthusiasts, no matter what some folks may say. The last time I was there, they had 914's, 944's, 928's and of course some 911's in progress. These guys love their work.

As far as the rear radiator is concerned, I think you might have some issues with getting enough cooling if you're running it hard, especially if the ambient temps are high. The proof will be in the final testing. I say this from lots of experience with rear mounted radiators in off-road vehicles, and the fact that that "ram-air" effect of a front mounted radiator is clutch in most cases. You can make up for it with oversized radiators, and a real good shrouded fan setup, but it takes some consideration for sure.

And although I can see your point about not wanting to mess with the fuel tank, the front mounted radiator of course helps with weight distribution.

Keep up the good work, I may still go this route some day.

For sure the test will be the hot Florida weather, the guys at RH also encourage the front mount and have endless hours of testing and development into their system and if my system fails me I will end up purchasing from them.

I do plan to also add a oil cooler that will fit into the right side fender. I will be using -10AN hose and fittings so hopefully this will help to drop the engine temps.

Again, the true test will be driving it like you said. The shroud setup and fans on my radiator are pretty good so the pull and amount of air flow will be critical