Hi all, we may run a new batch of cranks in January. If there is interest, let me know. January may seem like it is far off, but will be here quicker than you think. I will post some pictures in the coming days. John
Piston looks nice. What kind of coating is on the sides and top ? There is less of a dome on these then on the 2.5l pistons. What's the weight and CR ? Thomas
These use phosphate and graphite. There is more displaced cylinder volume to compress into the small volume of the combustion chamber. The increase in displaced volume would result in a higher CR, so this is corrected by adjusting dome height on the piston. The combustion chamber (formed by the head chamber and the piston top) ends up being more efficient without a dome and is compact. These weigh between 325 and 335g depending on bore size. John
A few pics of another set of pistons I have here. These weigh in at 305g. As can be seen in the last picture, the underside of the piston is fully machined and follows the contour of the top side. This particular set is 95.35 mm bore and is up for sale.
That 2.7 sounds very good. I guess a lot more torque will be available compare to 2.3 2.5 Very nice Anri
Yes there is more torque and a broader torque curve. The torque begins about 1000 rpm earlier compared to a 2.5. Pictures of the crank: Rods version I: John
Slide Throttles GB There may also be another batch of slide throttles available, for those interested, and these complement the 2.7l very well: John
That sounds super! I can imagine how fast will be with some Shrick cams and lots of rpm's... One thing I can think of a possible issue is: Since you are stroking the engine to its maximum the shell of the rod bearings must be thin ? On my E30 M3 S38-B36 the bearing shells are the same as on S14. But on S38-B38 BMW stroked the 3.6 to 3.8 via crank shaft and shorter connecting rods. Have you seen the rod bearing on B38 ?, they are almost like paper thin. And of course the S38-B38 week part is the rod bearings... Because from the long stroke they have lost of stress. On top of on the S14 owners like to rev their engines well over 7500rpm that means even more wear on the rod bearing.. I mean its not big deal just every 50-70k miles new bearing will be required if track use may be earlier... Because you don't want to hurt that expensive crank shaft... That crank is piece of art its like factory BMW Please correct me if I am wrong Its just my 02 cent A
This crank doesn't require special bearings. We use stock dimension rod bearings on the 2.7l build. I use the MS bearings, supposedly they are better then the E3 bearings. And our rods are longer not shorter. You are correct about the crank it looks like a piece of art. Actually I got my crank a few days ago........ :9:
That is very nice to keep the original size rod bearing. If I was still with my S14 I would get that kit immediately. Nice
Thats correct Thomas, with somewhat different material composition (I posted up some pics taken from the scanning electron microcope some time ago) and they allow to run larger clearances which allows the journals/bearings to run cooler with less friction and power loss. John
I remember seeing the pictures but didn't remember that thses were taken of the bearings. I have to look at them again, refresh my memory. Thomas
Hi Julien, the rods will be ready sometime this week. The pistons should be ready in about 4 weeks. I will contact you soon via email. John
Just a reminder we are thinking of running another batch of 2.7 cranks. We have a few people interested at this point, but not enough to do a batch. A down payment is required up front, and the rest just prior to delivery. If interested let me know or send me an email or PM. John
Jesus John, I am really glad I stepped out of the E30 M3 world.. I would be broke just buying parts.. ;-) Looking very nice! Cheers, Adwo
