Martin’s PRV bone yard…

Well a bit of progress. So I called a buddy over and we moved the ball a bit on the tuning. Only thing holding me back now is chronic oil leaks. Every compression gasket leaked on all the sensors - fixed those. The right cam plate on the back of the engine leaked - fixed that. Now fighting oilpan gasket leaks. The first one, cork type, leaked immediately; I am now using a silicone type and it too is leaking but not as bad. As soon as that is fixed I will then be in the tuning game. Not sure how to fix that yet though.

So tuning , the compression is stock and I am running the 2664. I did however port the heads significantly and am running lofty high lift cams and a Holly carb. I could get it to rev out but it would not idle below 1500 and the rpm "would surge". I backed the advance to 10deg BTDC adjusted the idle screw and enrichment screw and still not good - would not want to rev up (like video). After my buddy and I bounced ideas off of each other we got it to run pretty good by disconnecting the vacuum advance, setting a gap to the pump jet actuating lever and set it to 12btdc. My buddy found a link from Camaro 6 that reference the same problem using long duration cams. To get it to idle the butterfly is straddling the idle and transition circuit in the carb. It therefore "surges" and won't idle down. The fix is to back the butterfly down to the idle circuit, connect the distributor to the manifold vacuum, and crack the secondary butterflies a bit to add the needed extra fuel. At the moment my garage it under some major repair so I am a week away from tuning.

Any recommendations on how to seal this guy up? The is my most challenging hurdle at the moment.

There are lots of things to check firstly have you checked the float bowl levels very important, secondly have you set the butterflies before you start altering anything else put a small screwdriver very carefully down to the butterflies there are screws on the butterflie shaft slightly loosen them of and then carefully move the throttle back and forwards to the stop so that the Butterflys Centre themselves then do the screws up carefully.

....secondly ihave you set the butterflies before you start altering anything else put a small screwdriver very carefully down to the butterflies there are screws on the butterflie shaft slightly loosen them of and then carefully move the throttle back and forwards to the stop so that the Butterflys Centre themselves then do the screws up carefully.

Wow... do you really need to do that in this day and age for a new unit, supposed to be a well setup calibrated piece from the factory; I'm absolutely gobsmacked they expect you to fiddle with butterflies out of the box... they can't for sure?? If so that's dreadful... all I can say...

Martin

Well a bit of progress. So I called a buddy over and we moved the ball a bit on the tuning. Only thing holding me back now is chronic oil leaks. Every compression gasket leaked on all the sensors - fixed those. The right cam plate on the back of the engine leaked - fixed that. Now fighting oilpan gasket leaks. The first one, cork type, leaked immediately; I am now using a silicone type and it too is leaking but not as bad. As soon as that is fixed I will then be in the tuning game

yep... never use the cork

[mettersl]

If you are getting so many oil leaks, have you got a crankcase pressurisation problem? I don't know how these engines are vented...anyone more experienced care to comment?

I am with Martin on this one it should be pretty much plug and play. Out of the box I checked and reset the floats - they were close. I expect to tune it in the transition/WOT state with jets and refine it for my engine but just bolted on it should idle without setting gaps etc. The accelerator pump did not have any gap with the pump cam and after giving it one the engine settled it down and stopped running rich. As far as setting the idle screw that is done based on the application. It may have been OK if just dropped on a stock engine but remember I have the higher lift longer duration cams. Looking at my log books I fought a similar issue many years ago with my fiat SOHC engine. It took a bit of tuning but it idles at 800rpm now. The enrichment screws out of the box were close too.

Yes if there were a PCV valve I could replace it but unless I have overlooked something this is just an open system with the vent at the top of the left cam cover. With that said however I am with you that it acts like s clogged/blocked crank case breather.

What is common to use on the oilpan? Gasket or form in place gasket? Any other recommendations?

Unfortunately yes when I got mine tickover was terrible turnd out to be the butterflies weren't centralising plus a few other things float level was wrong, which obviously then affects the fuelling.
This holly is a pretty basic carb and mass manufactured also it is well over size for this application so The slightest thing out will have a greater effect on the engine rather than some stonking big cubic capacity engine. Also have you put a big vacuum gauge on, this can tell you in awful lot about what's going on.

[johnb]

Well a bit of progress. So I called a buddy over and we moved the ball a bit on the tuning. Only thing holding me back now is chronic oil leaks. Every compression gasket leaked on all the sensors - fixed those. The right cam plate on the back of the engine leaked - fixed that. Now fighting oilpan gasket leaks. The first one, cork type, leaked immediately; I am now using a silicone type and it too is leaking but not as bad. As soon as that is fixed I will then be in the tuning game

yep... never use the cork

Martin recommended the 'reinforced' gasket from Simon Auto, their part number 011011A and not the cork gasket 011011.
I used it and haven't had any leaks and it's been on for over 2 years now.

Cork one comes in the full gasket kit .Its ok if you don't overtighten the bolts .....just nipped up and it will seal .Having said that ,yes the other option is far better

Well a bit of progress. So I called a buddy over and we moved the ball a bit on the tuning. Only thing holding me back now is chronic oil leaks. Every compression gasket leaked on all the sensors - fixed those. The right cam plate on the back of the engine leaked - fixed that. Now fighting oilpan gasket leaks. The first one, cork type, leaked immediately; I am now using a silicone type and it too is leaking but not as bad. As soon as that is fixed I will then be in the tuning game

yep... never use the cork

Martin recommended the 'reinforced' gasket from Simon Auto, their part number 011011A and not the cork gasket 011011.
I used it and haven't had any leaks and it's been on for over 2 years now.

Wow... 2 years... where did they go... really 2 years??... but how long has it been on the road John?

[johnb]

Wow... 2 years... where did they go... really 2 years??... but how long has it been on the road John?

Not as much as I would have liked but 2250 km since its first MOT.
During that time it was with Andy for the paint job for several months, I don't drive it in the winter and it has to share its time on the road with the A110.

All really good points but what torque is the right torque? For the cork I am up for the education, what is the right process and target? Whatever it is I did not get it right. I thought the silicone gasket would get it but no. I am doing something wrong but obviously I don't know what. My garage is down for another weekend getting repaired so I can't go to the next steps just yet. Once over this hurdle and I am off to the races. I appreciate the advice. This forum has been great for good direction.

Ok I am getting some miles on the car and sorting out all the last troubles. So I think I have isolated my main oil drip problem to the mechanical fuel pump. It appears to be the main culprit. I have already replaced the base gasket and used the FPIG toyota material and it looks intact. What I see looks like it is leaking from the small vent hole on tower portion of the base casting and I see oil collecting on the hemmed flange of the diaphragm. My question is has anyone else had this problem??? Anyone seen a mechanical fuel pump leak oil from the vent hole or diaphragm? I am curious if it is unique to my car of a common issue.

Car = 1982 A310 with V6

thx

Brian

[johnb]

Ok I am getting some miles on the car and sorting out all the last troubles. So I think I have isolated my main oil drip problem to the mechanical fuel pump. It appears to be the main culprit. I have already replaced the base gasket and used the FPIG toyota material and it looks intact. What I see looks like it is leaking from the small vent hole on tower portion of the base casting and I see oil collecting on the hemmed flange of the diaphragm. My question is has anyone else had this problem??? Anyone seen a mechanical fuel pump leak oil from the vent hole or diaphragm? I am curious if it is unique to my car of a common issue.

Just taken a look at the fuel pump on my car and there's no sign of any leaks at the base gasket or vent hole.
I did have a problem several years ago with oil leaking from the vent hole on the mechanical fuel pump on the A110. This was a lever arm type pump and not a plunger type as on the A310. I can't remember the internal arrangement and what caused the oil to leak there. I found a NOS pump on Ebay and fitted that.

Has anyone tuned a Holley Carb conversion? If so what are your main jets, power valve, pump jets, cam and secondary spring you are using. I have my car driving like a mild sedan but it is nowhere near its power potential.

My current settings
** note my intake manifold and ports are opened up, exhaust ports opened up and I run a Dbilas cam
Mains = 58 (stock 51)
Pump Jets = 28 (stock 25)
Power valve = 8.5 (stock 6.5)
Pump cam = orange (stock)
Secondary spring = ? (stock )
Idle screws = 2 turns out
Advance = 10deg (no vacuum)

At the moment I don't believe my secondary is opening up. For the rest of the power range when I trounce the throttle it jumps into action, when I roll on the throttle it did have a hesitation but I solved that with updated mains and power valve and now it is pretty smooth. I believe it still does not have enough fuel at the upper rpm and it feels flat.

It has come a long way in a short time from, poor idling, hesitating during initial wide open trounce, hesitation and backfire when rolling on the throttle past 2500 rpm. Now it idles good, has lots of torque engaging first gear, is a little soft in the mid range and is flat at the higher rpm. Transition through the rpm range is smooth without bucking and backfiring. Cruise is pretty smooth too. I am in the neighborhood but still have bit to go.

I can't get on a dyno yet so I will still do some seat of the pants tuning. My next steps are to enlarge the mains, reduce the power valve and lighten the spring in the secondary. I am looking for any feedback by anyone who has already been tuning the Holley and wish to compare notes.

Thx,

Brian