free hit
counters
CA_Eclat - The Lotus Forums #ForTheOwners Jump to content


CA_Eclat

Basic Account
  • Posts

    3
  • Joined

  • Last visited

More Info

  • Name
    Jake Hecla
  • Car
    1979 Eclat

CA_Eclat's Achievements

Newbie

Newbie (1/14)

  • Dedicated Rare
  • First Post Rare
  • Conversation Starter Rare

Recent Badges

2

Reputation

  1. Hi All-- In the rebuild process, I have spent an inordinate amount of time thinking about sealants. Namely, I don't want to leak oil all over the new garage floor. In pursuit of that lofty goal, I have been trying to substitute as many of the old-fashioned sealants with modern high-performance ones. In later technical docs, Permabond A136 was spec'd as the preferred MBP-block sealant (thanks Tim!), however, it is not available over here, and I had a large tube of LH197 on hand. I ended up using Permabond LH197 on the main bearing panel, and carried out a few experiments using clamped parallels to check the sealant thickness. Despite a few minor issues with the experimental setup (don't drop the test articles...), I was able to get a good answer as to the film thickness. I liberally applied LH197 to both surfaces of the parallels and squeezed them together by hand such that the excess was expelled from the gap (and then cleaned up). After 1 hour of set time while clamped at 25C with two 8mm bolts @16ft-lbs 35mm apart, the film thickness was approximately .0005 +/- (.0003). My instruments are unfortunately too dilapidated to give better error margins on that number. However, I am confident it is good enough for the MBP. Additionally, I made an inquiry to Permabond regarding A136-LH197 crossover. Their response is as follows: "Thank you for your interest in Permabond adhesives and for contacting us about your application. Permabond A136 is a European product. Permabond MH196 is the technical cross to A136 and is readily available in the United States. Previous experience has shown that these products may be interchanged without any significant effect on the performance of the finished article. However, the formulations are not identical and differences may be observed under some circumstances. Either MH196 or LH197 may be suitable replacements for A136 and neither will increase the gap*; however, MH196 is the technical cross. I have attached the TDS for Permabond MH196 for your review. Feel free to contact me if you need further assistance." *emphasis mine I would like to thank Garry Kemp and Tim Engel for their insight and assistance in this. Best, Jake
  2. Peter-- I am very interested to hear how the 2.5 SC works out! I have left the bottom end standard. I had a long talk with the machinist I am working with, and opted to keep it as-is. What sort of supercharger are you working with?
  3. Hi All-- I am in the process of building my Lotus 907 motor to 2.4L spec with the help of Garry Kemp. I encountered a minor issue in that I could not install the provided Goetze-brand front seal. The outside diameter was a touch too large, and all efforts to press it in failed. I understand this is a relatively common issue, and sought to find a remedy in the local auto parts store. I turned to the Timken / National Seal catalog and identified a few potential candidate seal designs. Ultimately, I settled on the National 710194 seal (nominally 50x68x7mm), which has a double-lipped, spring-energized design. Even better, it is available at most US auto parts stores for under $12. The operational speed range is adequate (beyond 3k FPM) and the seal face design is superior to the original. The only hesitation I have is the seal material, which is Buna-N. While I don't anticipate extremely high temperatures in this part of the motor, Buna-N is only good to 250F, which leaves less of a margin than I would like. Personally, I would greatly prefer a fluoropolymer seal, but I cannot find anything available in this dimension. The dimensions of the National seal are much closer to the original GACO INC42497 seal measurements than the Goetze seal, and mounting was proportionally easier. I used an appropriately sized aluminum disc for centering, and observed no significant deformation on installation. While I have yet to subject it to a few thousand miles of hard running, I don't anticipate any issues. Other solutions out there seem to be the brown TTO F3159 seal (no info available), the original GACO INC42497, in addition to the Goetze 50x68x10. GACO is now a division of Orinoco Bearings, and has yet to provide me with a quote or specifications for the seal, so it's hard to see how they stack up head-to-head. I have included photos of the GOETZE seal that didn't mount for comparison to the original GACO seal to highlight the issue. Best, Jake
×
×
  • Create New...