Racecar Project - Connecting Rods
11-01-2005, 01:25 PM
#1
Nordschleife Master
Thread Starter
Racecar Project - Connecting Rods
I received my connecting rods today from Carrillo. Since a GT3R crankshaft was used, a connecting rod needed to be custom built. The rod on the left is the carrillo rod, each weighing 558 grams compared to a stock rod of 615 to 696 grams depending on the weight group. The rod on the right is out of my 911 turbo and is the same connecting rod found in the 964. It was in weight class 9 or 669-678 grams. Porsche allows for a 9 gram tolerance between any 2 rods. This particular stock rod has ARP rod bolts and was in my turbo car for 6 years run at 521hp and 7200rpm, so it is a stout rod. The Carrillo, while being considerably lighter than an average stock rod (with stock rod bolts) is stronger due to the 'H' beam construction.
I now have all of the parts to assemble and 'blueprint' the engine through the pistons and cylinders. I am only waiting for my new billet cylinder heads from Colin at Ninemeister. From there I'll have a cam specifically ground to match the flow of his cylinder heads.
I now have all of the parts to assemble and 'blueprint' the engine through the pistons and cylinders. I am only waiting for my new billet cylinder heads from Colin at Ninemeister. From there I'll have a cam specifically ground to match the flow of his cylinder heads.
11-01-2005, 10:20 PM
#6
Nordschleife Master
Thread Starter
I built the Carrillo rods with the 3/8 Carr bolt. I had wanted to use the GT3R Pankl titanium rods, however, I didn't feel comfortable boring out the 22mm wristpin bushing to the 23mm size the factory 3.8RSR P&Cs are. My other option was using Arrow rods from England which was my second choice, however, the custom nature of the rods made Carrillo the easy choice. The Arrow rods are in the 460gram range. I also changed the clearances from street car spec clearances to larger clearance which should help the oiling.
Trending Topics
11-02-2005, 07:59 AM
#8
Originally Posted by Tom W
I have Carrillo's too. What rod bolts will you use?
11-02-2005, 08:36 PM
#10
Burning Brakes
Join Date: Feb 2004
Location: Wilmington, NC
Posts: 756
Likes: 0
Received 0 Likes
on
0 Posts
I am sure that the Carrilorods are very close in weight, if not exact.
How close are they?
What is your tolorence for the weight differential?
How close are the pistons in weight?
Have you chosen a shop to do the ballancing of the entire assembly? (crank, rods and pistons)
Sorry for all the questions. I'm trying to see what the range is when buying parts like these and how you will deal with those variences.
Duncan
How close are they?
What is your tolorence for the weight differential?
How close are the pistons in weight?
Have you chosen a shop to do the ballancing of the entire assembly? (crank, rods and pistons)
Sorry for all the questions. I'm trying to see what the range is when buying parts like these and how you will deal with those variences.
Duncan
11-02-2005, 09:07 PM
#11
Addict
Rennlist Member
Rennlist Member
Duncan: If you want answers to those questions, you might want to call Rich at Jerry Woods for general info.
Rick: Your smokin' too much. The cost of the rebuild with these type of parts (and the labor) is probably more than your car is worth.
Rick: Your smokin' too much.
The cost of the rebuild with these type of parts (and the labor) is probably more than your car is worth.
11-02-2005, 10:37 PM
#12
Nordschleife Master
Thread Starter
Porsche will allow for a 9 gram difference between the heaviest and lightest rod according to the specifications. The heaviest pair are installed in 3&6, next heaviest pair in 2&5, and the lightest pair in 1&4. The Carrillo rods are all equal and all exactly 558grams and I have a card with the rod set that has the dimensions, weights, and rotating mass.
I have not weighted my pistons yet, but my experience shows that Mahle pistons are fairly close, however, I always balance them so they are exactly the same. In the past, I have sent out the bottom end as an assembly for dynamic balancing to a local shop here and will do the same with this one. I don't know what other shops do, but I like to get everything within .5gram.
As far as engine building, I'll do the engine assembly and blueprinting as I've always done.
I have not weighted my pistons yet, but my experience shows that Mahle pistons are fairly close, however, I always balance them so they are exactly the same. In the past, I have sent out the bottom end as an assembly for dynamic balancing to a local shop here and will do the same with this one. I don't know what other shops do, but I like to get everything within .5gram.
As far as engine building, I'll do the engine assembly and blueprinting as I've always done.
11-02-2005, 11:26 PM
#13
Three Wheelin'
Join Date: Oct 2002
Location: Pasadena, MD - Land of Taxes
Posts: 1,879
Likes: 0
Received 3 Likes
on
3 Posts
Originally Posted by Tom W
Rick: Your smokin' too much. The cost of the rebuild with these type of parts (and the labor) is probably more than your car is worth.
The cost of the rebuild with these type of parts (and the labor) is probably more than your car is worth.
If I did something like this I'd do it over a long period of time, buying parts as I find the best deal. I'm also talking about building it myself so I'd save on the labor. I figure it would still cost in the $10k to $15k area. It's also probably a project for the next house. I'll be shopping for a home with land and a detached garage.
