Frans, do you plan to do anything with the rockers/shafts? These are sometimes worn and having a similar problem not sure what to do. New ones are not available. What is an acceptable clearance between rocker and shaft?
807 Competition motor.
- Thread starter Frans
- Start date
I have not yet found badly worn 16 rockershafts but seen a few Gordini shafts worn. They can be 1) welded and reground or 2) new shafts made and grinded/ground to original.
That will help a lot and the wear will be halved.
I think if you're in deep water with a really badly worn rocker it can be reamed and bushed (Like a conrod)
Frans
That will help a lot and the wear will be halved.
I think if you're in deep water with a really badly worn rocker it can be reamed and bushed (Like a conrod)
Frans
Assembly
I have started assembly again after a long off period. Not that I was relaxing. I've done my gearbox and another for a customer.
I started with cutting the sleeve seals out of .004" shims (as discussed above somewhere) as seen in the pictures. It fits over the sleeve and lies on the seat of the sleeve. When assembling these one must remember to install the pistons in the sleeves beforehand because the big ends is so big that they don't fit through the sleeve. I've smeared the seats with sealant and installed in their positions. Then I fitted the clamps to hold them down.
The pistons is forged pistons and they don't have a front or back because of the gudgeon pin being dead center. The only reason I installed them in this way is because the valve cutout on the dome is slightly larger on one side and that side I fitted to match the bigger intake valve. In pics.
With the pistons in and connected to the crank the next step was to determine the true TDC for when the cam has to be dialled in. I fitted the degree wheel and bolted a piece of scrap flat bar onto the top in such a way that it hits the piston just before TDC. That means you cannot turn the crank over. By turning the crank CW it will stop against the bar. I noted the degrees and turned the crank CCW until it stopped against the bar again and noted the degrees again. I adjusted the degree wheel to match the difference. By doing this a few times it balanced out at 7.5 degrees ATDC and 7.5 degrees BTDC. Now remove the bar and turn the crank to 0 degrees. This is your true TDC. I marked the flywheel for future and then fitted the crank pulley and marked it as well. The timing can now be checked with a timing light if needs be.
The next step will be to mount the head loosely so that it can take the cam follower and then the cam timing can start.
Regards
Frans.
I have started assembly again after a long off period. Not that I was relaxing. I've done my gearbox and another for a customer.
I started with cutting the sleeve seals out of .004" shims (as discussed above somewhere) as seen in the pictures. It fits over the sleeve and lies on the seat of the sleeve. When assembling these one must remember to install the pistons in the sleeves beforehand because the big ends is so big that they don't fit through the sleeve. I've smeared the seats with sealant and installed in their positions. Then I fitted the clamps to hold them down.
The pistons is forged pistons and they don't have a front or back because of the gudgeon pin being dead center. The only reason I installed them in this way is because the valve cutout on the dome is slightly larger on one side and that side I fitted to match the bigger intake valve. In pics.
With the pistons in and connected to the crank the next step was to determine the true TDC for when the cam has to be dialled in. I fitted the degree wheel and bolted a piece of scrap flat bar onto the top in such a way that it hits the piston just before TDC. That means you cannot turn the crank over. By turning the crank CW it will stop against the bar. I noted the degrees and turned the crank CCW until it stopped against the bar again and noted the degrees again. I adjusted the degree wheel to match the difference. By doing this a few times it balanced out at 7.5 degrees ATDC and 7.5 degrees BTDC. Now remove the bar and turn the crank to 0 degrees. This is your true TDC. I marked the flywheel for future and then fitted the crank pulley and marked it as well. The timing can now be checked with a timing light if needs be.
The next step will be to mount the head loosely so that it can take the cam follower and then the cam timing can start.
Regards
Frans.
Attachments
Last edited:
The SUMP!! Since Ross has found this Fuego Turbo for parts he wants the Fuego high volume oil pump fitted. That made the old sump not to fit at all. At first I tried modifying it to adapt to the new oil pump but that turned out to be something I didn't like. So I got the Fuego sump from him and started from scratch.
I started the normal way by making templates from cardboard and then the real thing from plate. All the way around the bottom should be theoretically sealed but that is hard to implement with tin-snips and a file so it is good as can be seen in the pics. All the others I built looks like that and works. I didn't like the way Ross made his hinges so I followed my old method with a real piano hinge. It can be seen in the pictures. Take note that the pop rivets used are steel ones. Aluminium ones doesn't last and it might just cause an engine failure. When using the steel pop rivets you have to make sure that they are a little too long so that the ends can be pinched close. That will prevent the little head of the nail to fall out and end up some where in the engine. The cover that goes over it all is a tight fit around the edges and there is another cover that I will be welding in position to prevent sideways oil loss through the hole for the pump.
Because the original drain is now outside the main compartment I needed to move or add an extra drain plug. The baffles will prevent proper drainage to the original hole. In the other engine I built (Alpine engine) there was a drain at the very end of the alloy sump. On the Targa I changed the oil at the halfway mark. I could then poke a hacksaw blade into the drain hole and so open the baffle to drain the oil.
If you want to test the sealing capabilities of your baffles you can test it by filling with a thin oil (hot oil is thin) and tilt the sump at 45 deg. Note the way the oil flows out of the pickup chamber and you will know how well your fitting is. I did some brainstorming once and came to the conclusion that 1g is equal to the sump tilted 45 deg....... (open to different views). Today's cars can pull one g cornering. Luckily the pump volume is very low because of the tight tolerances in engines.
The sump is not complete yet and I will add the outstanding as time goes on.
Frans.
I started the normal way by making templates from cardboard and then the real thing from plate. All the way around the bottom should be theoretically sealed but that is hard to implement with tin-snips and a file so it is good as can be seen in the pics. All the others I built looks like that and works. I didn't like the way Ross made his hinges so I followed my old method with a real piano hinge. It can be seen in the pictures. Take note that the pop rivets used are steel ones. Aluminium ones doesn't last and it might just cause an engine failure. When using the steel pop rivets you have to make sure that they are a little too long so that the ends can be pinched close. That will prevent the little head of the nail to fall out and end up some where in the engine. The cover that goes over it all is a tight fit around the edges and there is another cover that I will be welding in position to prevent sideways oil loss through the hole for the pump.
Because the original drain is now outside the main compartment I needed to move or add an extra drain plug. The baffles will prevent proper drainage to the original hole. In the other engine I built (Alpine engine) there was a drain at the very end of the alloy sump. On the Targa I changed the oil at the halfway mark. I could then poke a hacksaw blade into the drain hole and so open the baffle to drain the oil.
If you want to test the sealing capabilities of your baffles you can test it by filling with a thin oil (hot oil is thin) and tilt the sump at 45 deg. Note the way the oil flows out of the pickup chamber and you will know how well your fitting is. I did some brainstorming once and came to the conclusion that 1g is equal to the sump tilted 45 deg....... (open to different views). Today's cars can pull one g cornering. Luckily the pump volume is very low because of the tight tolerances in engines.
The sump is not complete yet and I will add the outstanding as time goes on.
Frans.
Attachments
Hi All,
With the sump now complete I welded little 3mm rods on the bottom of the oil pump pick-up. They will be like stand-offs so that when the sump gets a hit from the bottom, the pick-up is not closed completely and oil can be drawn in on the sides next to the stand-offs. This could help even if you have a sump guard and a heavy knock dents the guard inwards and up against the sump. Especially on a rally car as this one will be.
The next step was to finally dial the cam in and lock the adjustment to the guessed position. This one I've done the same as the RA5 cams that I normally use. (this is a Kiwi design cam). On the RA5 (Renault Africa Stage 5) cams and their equivalent that I got I set the the cam in such a way that when the intake is fully open, the crank is at 110 deg ATDC. I hope that this will be close but it will be proved on a dyno.
I removed 2 valve springs and replaced them with 2 soft springs that can be depressed by hand. After the cam is locked in its position the motor can now be turned and the valve to piston clearance can be checked. While turning the engine the valves can be pushed further down as what the cam does. I can continually monitor if and how far I can push the valve down before it touches the piston. All this can be done with putty on top of the piston as many people do.
The mounting of the toothed wheel and the pick-up is completed as well. I have failed here because the idea was to mount it on the other side but now the alternator will go there with the result that the missing tooth is now about 180 deg out. Will have to fix that!
The other pics show the mounting plate with the crossmember. Note how high the mountings are because then the crossmember can be straight and at the ends is the angle brackets that will rest on the chassis rail. The engine mountings are in place and then the last pic shows the mounting plate fixed in position with its countersunk slotted screws. That is just there for ease of assembly because the timing cover will pull everything tight against the block.
Regards
Frans.
With the sump now complete I welded little 3mm rods on the bottom of the oil pump pick-up. They will be like stand-offs so that when the sump gets a hit from the bottom, the pick-up is not closed completely and oil can be drawn in on the sides next to the stand-offs. This could help even if you have a sump guard and a heavy knock dents the guard inwards and up against the sump. Especially on a rally car as this one will be.
The next step was to finally dial the cam in and lock the adjustment to the guessed position. This one I've done the same as the RA5 cams that I normally use. (this is a Kiwi design cam). On the RA5 (Renault Africa Stage 5) cams and their equivalent that I got I set the the cam in such a way that when the intake is fully open, the crank is at 110 deg ATDC. I hope that this will be close but it will be proved on a dyno.
I removed 2 valve springs and replaced them with 2 soft springs that can be depressed by hand. After the cam is locked in its position the motor can now be turned and the valve to piston clearance can be checked. While turning the engine the valves can be pushed further down as what the cam does. I can continually monitor if and how far I can push the valve down before it touches the piston. All this can be done with putty on top of the piston as many people do.
The mounting of the toothed wheel and the pick-up is completed as well. I have failed here because the idea was to mount it on the other side but now the alternator will go there with the result that the missing tooth is now about 180 deg out. Will have to fix that!
The other pics show the mounting plate with the crossmember. Note how high the mountings are because then the crossmember can be straight and at the ends is the angle brackets that will rest on the chassis rail. The engine mountings are in place and then the last pic shows the mounting plate fixed in position with its countersunk slotted screws. That is just there for ease of assembly because the timing cover will pull everything tight against the block.
Regards
Frans.
Attachments
does that matter? couldnt you compensate by swapping the pairs of plug leads?
I like the way he says "WHEN the sumps gets a hit" He must think I am a rough driver or something.
That was an option I looked at because it would have been easy as it is a wasted spark system going in.
The actual position should be at the "40" mark. If you take 180 deg from there you will note that the pickup would've been around the 7 o'clock mark. That was too low and across the sump.
The actual reason for this fault is because the rotating stuff was balanced mid last year and we needed to get the pulley to be balanced as well. At that stage the planning was far from cross members and engine mountings so it was overlooked.
Ross,,,,,,,I'll stick to my statement.
Regards
Frans
Closing up
With most of the fiddling complete the assembly started and was finalised with Threebond. It is the first time I've used it and heard good stories about it.
With the assembly done the carbs had their turn. They were in a sorry state and me and Ross battled with some of the things and specific the butterfly shafts and bearings. Ross managed to bend both of them in the removal process (he bent it because he had the hammer). Then with some special acid treatment all the little channels was opened and clean and I took them home to start the overhaul process.
That went fairly straight forward except for the butterfly shafts. The only ones available were to long. I had to turn them down in size which in itself was tricky because of the flats in the shaft. They can't be centralized in a 3 jaw chuck. I made an extra brass bush to support the shaft and used the ends, one to clamp and the other to guide. It turned out well as can be seen in the pictures. Now the bearings could fit but the thread holding the linkages had to be tapped deeper with a M7 die. That is easy but not if it is a shaft that has 2 flat sides! The die has nothing to guide itself so I begged and promised it the world and spent a lot of patience on it. It worked in the end. Then it was shutting off the chokes. This is a known fact that when the choke circuit is blanked off there is a gain in hp. Why, I don't know. Remove the choke pistons, turn substitute ones and Loctite them in position. Then put a homemade cover on chuck the mechanism. A race car don't need a choke!
That complete, the mounting started and the shafts and linkages were cut and sized for the the 2 carbs to sit side by side.
The engine completion is getting closer now and the only big thing outstanding is the extractor. Ross will build it when it is in the car because he has strange ideas about the route the pipes must go.
We will see about the tuning, might take it to a dyno. Hp figures will be interesting to see. At this stage I won't take a guess but I hope it is satisfactory. Ross had it at a head specialist to flow the head and went with a cam that he specified. It is slightly milder than the one I specified in the 1800. The target for me will be around 160 hp.
Regards
Frans.
With most of the fiddling complete the assembly started and was finalised with Threebond. It is the first time I've used it and heard good stories about it.
With the assembly done the carbs had their turn. They were in a sorry state and me and Ross battled with some of the things and specific the butterfly shafts and bearings. Ross managed to bend both of them in the removal process (he bent it because he had the hammer). Then with some special acid treatment all the little channels was opened and clean and I took them home to start the overhaul process.
That went fairly straight forward except for the butterfly shafts. The only ones available were to long. I had to turn them down in size which in itself was tricky because of the flats in the shaft. They can't be centralized in a 3 jaw chuck. I made an extra brass bush to support the shaft and used the ends, one to clamp and the other to guide. It turned out well as can be seen in the pictures. Now the bearings could fit but the thread holding the linkages had to be tapped deeper with a M7 die. That is easy but not if it is a shaft that has 2 flat sides! The die has nothing to guide itself so I begged and promised it the world and spent a lot of patience on it. It worked in the end. Then it was shutting off the chokes. This is a known fact that when the choke circuit is blanked off there is a gain in hp. Why, I don't know. Remove the choke pistons, turn substitute ones and Loctite them in position. Then put a homemade cover on chuck the mechanism. A race car don't need a choke!
That complete, the mounting started and the shafts and linkages were cut and sized for the the 2 carbs to sit side by side.
The engine completion is getting closer now and the only big thing outstanding is the extractor. Ross will build it when it is in the car because he has strange ideas about the route the pipes must go.
We will see about the tuning, might take it to a dyno. Hp figures will be interesting to see. At this stage I won't take a guess but I hope it is satisfactory. Ross had it at a head specialist to flow the head and went with a cam that he specified. It is slightly milder than the one I specified in the 1800. The target for me will be around 160 hp.
Regards
Frans.
Attachments
I like to think of it as a joint effort, I dont like taking all the praise.
Next time guys, use a nut, some washers and a suitable length of pipe of a dimeter large enough to put the bearing through but small enough that it will rest on the holder. WD40 in copious amounts can't hurt.
unlike your highly conventional, plain vanilla effort as shown previously!
question: i take it you are using the TPS for a megajolt in lieu of suitable manifold vacuum?
Last edited:
Frans, I have finalised the design for the extractor, you might think its a bit strange but I think it has a certain french flare. Can you build it for me?
Attachments
i like the big chrome pipe tip - that really finishes it off nicely.