pampa Posted January 25, 2017 Report Share Posted January 25, 2017 I have fitted a Mocal oil cooler to my 67 4a ,it has the sandwich fitting between filter head and filter. After fitting oil pressure has gone from 70/75 cold to 85/90 cold and 60 hot to 65 hot. I am worried that because the oil gauge is before the sandwich is there a restriction caused giving a higher reading and actually less oil getting to the motor. Looking thru filler hole the rocker gear is getting oil but doesn't seem to be as much as usual. I fitted a temporary gauge to the plug at the back of the head and the gauge shows nil pressure but there is some oil there as a slight leak came from the connection. The hand drawn fitting instructions that came with the kit are very vague. Any help would be appreciated. Quote Link to post Share on other sites
MichaelH Posted January 25, 2017 Report Share Posted January 25, 2017 Most 4 cylinder road cars don't need an oil cooler as the oil doesn't get that hot. So you may be over cooling your oil. Run the car and feel the oil cooler pipes Because the engine is wet liner the is no continuity between the hot cylinders and the main bulk of the block so heat does not conduct down to the block - oil doesn't get heated so much. Most oil cooler "sandwiches" are total flow - so all the oil goes through the cooler and transmits pressure thru to the engine My comments are supported by experience of running an oil temp gauge Regards MichaelH Quote Link to post Share on other sites
GT6M Posted January 25, 2017 Report Share Posted January 25, 2017 Can you tell us wot size of fittings are used. In particular, the INSIDE dia oft fittings, not the hose, but hose too if ye no its dia cos if they are less than 9/16th, then thats the size of the pick up feed frae oil pump and the galley bore is 7/16th to 1/2 inch in bits me bet is that ye,ve put the stuff reccomended by inept / unelightend sellers of such things,!! As most sell 1/2 inch fittings, thee,s got a 5/16th wol in em, even a 1/2 inch fitting is only aboot 3/8th tops, see yer prob noo!!! M Quote Link to post Share on other sites
pampa Posted February 5, 2017 Author Report Share Posted February 5, 2017 Michael,Can understand most Tr's in the old country not needing a cooler as your max rarely gets up to our min,try 35 to 45 for a couple of months. I wasn't overcooling the oil as they were the pressures at start up and running in the shed . I decided to fit a cooler when I saw 20 Psi in the pits after a 5 lap race in 38 Deg.also drops to a bit under 60 in the race and also on the 300km freeway trip at 110 to the circuit..The unit is a local which I purchased from Rimmers for my particular car so thought it would be ok. it has 12.5mm hoses and fittings. The hoses heat up and have a strong pulsing feeling. I haven't fitted a temp gauge yet as have to work out where a suitable outlet to fit it. I run Penrith HPR30(Mineral 20/60)with Liqui-Moly. Had hoped someone on here would know if these coolers when fitted actually cause restrictions as they are fitted to a lot of cars thought someone would have an answer. I also hoped someone would know how much oil and pressure goes to the rocker gear as mine has not a lot and fitting a gauge to the bung at the back of the head showed no pressure. Quote Link to post Share on other sites
tim hunt Posted February 5, 2017 Report Share Posted February 5, 2017 I have a 13 row Mocal cooler fitted just behind the grille of my 4A. I also have the sandwich plate take off between filter head and block and an in line thermostat between that and the cooler. I can't account for the significant cold pressure difference and don't see this on my car. However, I do see the same 5psi increase hot,70-75psi on my gauge, with the cooler fitted and always attributed this to somewhat higher viscosity of the cooler oil. I use Millers Classic 20w50. Tim Quote Link to post Share on other sites
oldtuckunder Posted February 5, 2017 Report Share Posted February 5, 2017 I'm fairly certain that the feed to the rockers on the 4 pot is the same as the 6 (but someone will correct me if I'm wrong) and its via a flat on the rear of the cam which acts like a small pump itself, or rather restricts the main oil flow so that only a small pulse once per rev gets sent up to the rockers, as the rocker shaft requires very little lubrication. So I don't think you will get any sensible pressure reading from the plug on the back of the head. If you really want to check oil pressure take it from one of the plugs into the oil gallery on the side of the block, that will tell you (within limits of the accuracy of the gauge say +-10%) what oil pressure you really have where it counts, what the oil pressure is pre filter and oil cooler may be an interesting number bit not sure what it really tells you, other than in this case something has changed You didn't say which kit you got, was it one with a thermostat built into the head or one with the thermostat in the pipes (or one with no thermostat at all!) or if the pipes are push fit with clips or have metal fittings, As GT6M said lots of extra pipe work with extra un-optimised fittings, and adaptor plates and thermostats can introduce a fair amount of restriction into the system. Most kits are designed to meet a perceived need and easily fit the space available rather than being optimised for function. Alan Quote Link to post Share on other sites
MichaelH Posted February 5, 2017 Report Share Posted February 5, 2017 (edited) Several comments: running the car at high speed for a long time will actually drop the oil pressure - eventually to almost nil as I witnessed in my brother's 4A driving through the night to watch Le Mans we had to stop at about 4amto let the whole thing cool down Next from personal experience racing my 4 the whole thing will get a bit limp after a race it needs to be run for a while with fan just to cool down.(my race car has an oil cooler/oil temp gauge) Both of these situations are in practice quite rare in GB with the ambient temperature and our speed limits never mind the traffic. Our TRs will run all day at 70 which is just over 3K revs in OD top without overheating Michael Edited February 5, 2017 by MichaelH Quote Link to post Share on other sites
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