Jump to content

Recommended Posts

Well my simple head off project from last year has ended up with a complete engine rebuild and in inline rebore. So I now have the pleasant prospect of putting it all back together with a new sprint cam, unleaded head conversion etc etc. Its been a while since my Webers were tuned and I am sure that all these changes will need some fine tuning.

 

So the question is do I bother with a rolling road or just a good old fashioned tune up?

 

I live near Reading so any recommendation is this area much appreciated.

 

I should also put in a word for Classic and Modern based in Bracknell who dropped everything to get my rebore on the crank and cam finished in three days!

 

Hopefully the car and I will be ready for the trip to the Le Mans Classic.

Link to post
Share on other sites

On a rolling road, the technician(s) will be able to assess the performance right across the usable rev. band, and adjust accordingly.

With the change in formulation of petrol over the years, what worked well in the past may no longer do so. This was confirmed when I took my TR4 to Revington last September, and Dan & Carl found a somewhat weak mixture in the mid-range with my HS6s. A change of needle transformed the performance and now, with foot hard on the floor, it pulls cleanly from 1800 to over 5000 (my normal maximum for road use), with no hesitation or sign of pinking.

Well worth it!

Ian Cornish

Link to post
Share on other sites

Good rolling road @ Stanton Motorsport near Membury services off the M4. Not too far from Reading.

Link to post
Share on other sites

The invoice says AUD1487 Needle carb RE (2 off).

However, each modified engine is likely to differ, so these might not work on another.

Ian Cornish

Link to post
Share on other sites

I think what I will do is get the engine running for about 500 miles or so, then tighten up the head etc and put back on those bits which have fallen off and then go for a rolling road. With a following wind the engine and gearbox will be back in the car by next weekend so le Mans is looking possible.

 

Tks

 

Richard

Link to post
Share on other sites

I think what I will do is get the engine running for about 500 miles or so, then tighten up the head etc and put back on those bits which have fallen off and then go for a rolling road. With a following wind the engine and gearbox will be back in the car by next weekend so le Mans is looking possible.

 

Tks

 

Richard

That's what I did as well (now almost 10 yrs ago...). I wanted an all round, smooth-running engine that's capable for daily routine. I settled for balanced (weight) pistons and c/rod, a few kgs off the flywheel etc. In real life, I will not exceed 4500 - 5000 rpm, certainly not with the aid of an OD.

Link to post
Share on other sites

My perspective is dated: My cars were all late 1950s and early 1960s. My newest is 1966. That said, if it were me, I would re-read Philip Hubert Smith's book, "Tuning for Speed and Tuning for Economy". The book is still available and, although published in 1972, is a classic for sports car owners of the fifties, sixties, seventies and maybe the eighties.

 

Sort your car out according to what you learn. Then -maybe - if you think it is necessary, take it for the rolling chassis. If you make that extra effort, you will understand - and love - your car even more.

 

And then, of course, post the results.

 

Good luck.

 

PMH

Link to post
Share on other sites

Richard,

 

Be aware that putting your car on a rolling road for tuning

demands that the engine be revved somewhat vigorously.

More than a little worrying when you are still running in.

 

AlanR

Link to post
Share on other sites

Richard,

 

Be aware that putting your car on a rolling road for tuning

demands that the engine be revved somewhat vigorously.

More than a little worrying when you are still running in.

 

AlanR

 

Yep, make sure it's proper run in first and take a valium. It's the best way though.

Link to post
Share on other sites
  • 4 weeks later...

So the car came back to me yesterday, with the engine back in and looking good and sounding great (no rolling road anytime soon). Took it for a test drive and 3 miles form home....

The rear offside wheel came off

lucky for me I had just turned a very slow corner at 5mph so no body damage. The lower stub axle parted company at the nut.

I can officially comment that the AA is rubbish at recovery and it took 12 hours to get me 3 miles.

Anyway I was able to get 2 new uprated CV axle shafts form Rimmers sent down same day and now the car is back up and running.

Will see what happens over the weekend and hopefully I will be in Blue Sud on Friday.

Many thanks to all those who have posted

Richard

Link to post
Share on other sites

Hi Richard,

can you tell more about how the hub failed.

Did the stub axle break?

Did the nut undo and come off

Something else.?

How old is the hub or when was it last rebuilt ? - rebuilt hubs are bad news.

 

Roger

Link to post
Share on other sites

Hi Roger

 

the stub axle sheared at the nut, looking at it one can see that over a period of time a number of cracks, When I rebuilt the car back in the 90's I am not sure I renewed these so I guess after 52 years it decided to retire.

 

Lucky for me I was not going fast so no damage and now I have two shinny new CV based replacements.

 

R

Link to post
Share on other sites

Hi Richard,

many thanks for the info. That al fits into what is now happening more regularly.

After 40/50 years they are dying.

 

Both Moss and Bastuck make new hubs to the OE design.

I have had a pair of Moss hubs on my 4A since April 2017 and they are running perfectly.

 

Good luck with the CV shafts.

 

Roger

Edited by RogerH
Link to post
Share on other sites

Done over 9000 miles with CDD CV driveshafts on my 4A, one of the best upgrades ive made.

Good job your old one broke near home and not on a fast bend on way to CLM.

Chris

Link to post
Share on other sites

I acquired my new hubs from Rimmer Bros

Quite easy to fit once I removed the silencer

One note of caution is making sure to also buy the spacers. This I found out once I had fitted the hubs, I bought these from Moss for £19 for two 6mm thick

Tks

R

Link to post
Share on other sites
  • 2 months later...

Well it's been awhile since Le Mans but the car made it there and back without to much trouble and the engine should now be nicely run in. The CV shafts seem to be good and no funny clunks when moving off.

 

 

I now need to work on a few other cosmetic things like a new soft top.

Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Restore formatting

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

Loading...
×
×
  • Create New...

Important Information

Please familiarise yourself with our Terms and Conditions. By using this site, you agree to the following: Terms of Use.