Yowzer Posted December 3, 2023 Share Posted December 3, 2023 I dunno if you've experienced this but the 4M sump is so shit, under heavy braking the oil fucks off from the pickup so definitely whip some better baffles in there. How different is the 7M pump from the 5M? I managed to combine pieces of both 4 and 5M pumps to bolt right in, don't think I had to fuck with the crossover pipe either. Quote Link to comment Share on other sites More sharing options...
sheepers Posted December 3, 2023 Share Posted December 3, 2023 Yea cheers for that. Tbh this car isn't exactly going to be setting lap records anywhere but a couple of baffles in the sump can't hurt as you say. 5M pump is radically different to 7M. 7M left. Oil outlet back of motor and steel tube pickup pointing towards the rear 5M right. Oil outlet front of motor (4M sump won't clear crossover pipe) and cast pickup which is front/mid sump which also won't clear the sump. 5 Quote Link to comment Share on other sites More sharing options...
cletus Posted January 9 Share Posted January 9 Looking at your lifter situation If they don't work or cause problems, I wonder if it would be easy to make some adjustable solid ones that just plop in the holes with an adjuster/pivot/jam nut at the top Quote Link to comment Share on other sites More sharing options...
sheepers Posted January 9 Share Posted January 9 i suppose i could? imma try it as is and see what happens. 1 Quote Link to comment Share on other sites More sharing options...
JustHarry Posted January 10 Share Posted January 10 @sheepers I assume you've probably done a web search but it seems unlikely they should have no movement perhaps the ones you have are stuck? https://www.celicasupra.com/threads/lash-adjuster-service-pictorial.59000/ I did a rb25 head a few years back and the lifters in that were impossible to compress. Seemed to work ok when assembled Quote Link to comment Share on other sites More sharing options...
sheepers Posted January 12 Share Posted January 12 yea na i didnt explain myself very well. they're not stuck, but the non return valve in the base of them is extremely efficient and once they have oil in the base of them they dont compress. im now clear on how they work and why i should be very careful with the pressure to the lifter gallery. when they are installed its assumed that they are empty of oil. so the fist time they see oil pressure they pump up until the cam follower is touching the back of the cam. the oil pressure can extend the lifter when the cam lobe isn't pressing on it so it pushes it up against the base circle, when the lobe comes around the non return valve inside the base of the lifter makes sure the lifter doesn't collapse and the oil pressure reg makes sure the lifter cant "pump up" the lifter and open the valve on the back of the cam. thing is that my calculations show that even something like a thinner or worn copper washer on the clamping bolt can influence the pressure by more than 5% so there must be some wiggle room for increases and decreases in the lifter gallery pressure. also - the factory manual gives no information on any settings, spring lengths or spring compression rates for the pressure reg. it just says clean it and put it back together. ill experiment with a little bit more pressure and see what happens, like i say i can generate oil pressure in the motor without the motor spinning so ill fuck around with it on the stand and see what happens. 2 Quote Link to comment Share on other sites More sharing options...
xsspeed Posted January 12 Share Posted January 12 (I'm no expert but) why do you think you actually need more pressure? i thought the lifters just take out the slack so it was purely down to differential pressure being enough to keep the slack out of this system (without getting to pump up scenario) Or are you thinking existing pressure would be too low to keep lifters 'slackless' as a result of new cam/rpm or something? Quote Link to comment Share on other sites More sharing options...
sheepers Posted January 12 Share Posted January 12 I'm really just thinking that the extra load on the lifter ball and the extra spring pressure would need a bit more oil pressure to compensate. That's about it Quote Link to comment Share on other sites More sharing options...
Roman Posted January 12 Share Posted January 12 Hey what sort of cams and springs will this be running? Edit: nevermind i figured out how to read. ~280 deg, this is gonna be sweet! Im guessing the lift value is before accounting for rocker ratio 1 Quote Link to comment Share on other sites More sharing options...
anglia4 Posted January 20 Share Posted January 20 What do you run 50:1 in? That’s a pretty lean 2 stroke mix! Quote Link to comment Share on other sites More sharing options...
JustHarry Posted January 20 Share Posted January 20 26 minutes ago, anglia4 said: What do you run 50:1 in? That’s a pretty lean 2 stroke mix! Standard stihl 3 Quote Link to comment Share on other sites More sharing options...
anglia4 Posted January 20 Share Posted January 20 Aha. All my garden equipment is cheap shit that needs 25:1 40:1 for my bike though. /spam Quote Link to comment Share on other sites More sharing options...
sheepers Posted January 20 Share Posted January 20 Took me a minute to figure out what you were talking about. Those numbers were written in there before I moved in. No Fucking idea what they were used for tbh Quote Link to comment Share on other sites More sharing options...
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