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Tr4Deano

Supercharging TR4

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Rebuilding my TR4 to fast road spec and at the moment upgrading suspension, brakes etc. Will be starting on the engine this winter and I am thinking of fitting the moss supercharger kit with boost upgrade.Was going to go forged 89mm Pistons, big valve head, forged rods, 270 cam, 123 dizzy & lower the CR to 8:5:1. As you can see I am spending some £ on this and don't want the project to be a flop, any advice on this welcome.

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Deano

 

Peter Cobold is the guy you need to talk to

 

Sounds like it will be a brilliant car -good luck with the build

 

Graze

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Hi TR4Deano, Welcome to the forum.

Your first post is timely. I'm giving a talk on "Supercharging TRs for the road" at the IWE nest saturday. See you there ? Other s/c TRs and owners in the Sunday am arena event 10am.

 

 

The 8.5compression head is a good idea, and should be OK at around 8psi boost at 3500rpm on 97RON or better**. If the Moss upgrade gives more boost than that then you need more octane, or other measures to defeat detonation.

The standard cam is best. If that 270 cam gives overlap more than standard you'll dump boost in the overlap period straight down the exhaust.

Overlap is nowadays regarded as a no-no

Detonation will kill expensive forged pistons a mere very few seconds after a stock piston will give way. I suggest fit stock pistons until you are certain knock is not present under any operating conditions.

Porting and valve jobs will help get the best from the boost but make the risk of detonation higher, because there's more mixture in the chambers. So to some extent you will be exploring new territory. Because of this I would suggest starting with the standard pulley and fit the higher boost one when you are certain knock is under control. Also I would not make the exhaust valve seats thin, keep a good fat seat so that the extra heat the valves are exposed to can conduct away from the valve head. Hot evs contribute to detonation risk. A bit more lift than stock would be good.

Unless you are going for high rpm then forged rods arent really necessary. They're normally needed to resist the huge high rpm tensile loads around the caps/bolts. Supercharging allows a normal 5k rpm limit to be used. Boost adds to compressive loads where forged rods arent needed.

The programmable 123 disy allows tuning the 'boost retard' which my prove valuable in the battle aginst knock.

A cold air intake ( filtered of course) is I think essential for your plans, the Moss hot air intake is not best practise.

 

An engine under 9 to10 psi boost will burn approx 50 % more fuel on each combustion stroke.You cannot fail to be impressed with the outcome, form 1000rpm upwards. Loads more torque: about 50% more. Even 7psi boost will deliver about 30% more torque.

 

And I recommened reading Alan Allard's book.

 

 

Peter

 

edit: I suppose there is no 8.5:1 head for the 4, unlike the TR 6 where low comp USA heads are available, I would suggest that keeping the stock gasket is better than fitting a thick decompression gasket. So you will have to use special pistons. A thicker than normal crown above the first ring groove is a good idea. And preserving squish will also help deter knock but that requires a crown that is raised below the squish segment in the head.

 

** based upon my assumption that the TR4 naturally aspirated head at 10.5:1 doesn't knock on 97RON. Could be wrong.

Edited by Peter Cobbold

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One can fit solid copper gaskets, and more than one can be used - I know, I have had to use two because the head (already much modified and high compression) warped when all the coolant disappeared when at full chat on a rolling road. The head had to be skimmed and, to avoid a CR of over 11, I inserted a second copper gasket. The car has been running very well for 20 years with this arrangement, but it is not supercharged - perhaps Peter could say whether such an arrangement would work on a supercharged engine?.

Ian Cornish

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Deano, is your car RHD? I'm interested to know if it's possible to adapt the Moss kit to RHD.

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One can fit solid copper gaskets, and more than one can be used - I know, I have had to use two because the head (already much modified and high compression) warped when all the coolant disappeared when at full chat on a rolling road. The head had to be skimmed and, to avoid a CR of over 11, I inserted a second copper gasket. The car has been running very well for 20 years with this arrangement, but it is not supercharged - perhaps Peter could say whether such an arrangement would work on a supercharged engine?.

Ian Cornish

Ian. That's good to know. I had been concerned that the wet liners might not like a solid copper gasket and would move around and leak after a while.

Boost raises the effective compression ratio. 8psi adds about two ratios - but only at wot at the higher rpm. Full throttle at say 2000rpm the boost may be around 4psi and the CReff only one ratio up. So Creff changes with the boost/rpm relationship. And holding 8psi boost is never for long - the road runs out!

Peter

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I'm interested to know if it's possible to adapt the Moss kit to RHD.

Pete,

Moss' ebay offering has better pics than the catalogue:

http://www.ebay.co.uk/itm/TRIUMPH-TR2-3A-LHD-SUPERCHARGER-KIT-PART-NUMBER-150-128-/171305602594

There may be conflict of underside bits with the steering shaft. The vacuum actuation of the bypass and the choke mechansim on the SU. I suspect neither are insuperable: remove the bypass, and move the carb slight forward and tilted, float chamber re-mounted to suit.( easier with a HS than the HD supplied) And feed cold air to the filter somehow.

Peter

Edited by Peter Cobbold

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Thanks 4 all the advice, my TR4 is a RHD, spoke to the chaps at Moss and they say that air filter could be an issue in fitting kit to a RHD but was going to remove this anyway and fit a custom cold air feed to run between supercharger and rocker cover and down to rad area, I also think the vacuum bypass could be an issue but have downloaded the specs from Eaton and this unit can be moved to opposite side of supercharger, if the carb itself is an issue Its an excuse to fit the mikuni upgrade available from some lads in the states. Will see if I can get next weekend off and get to the IWE.

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I see that Revington lists solid copper gaskets in various thicknesses: 1.0, 1.2, 1.5, 2.0 and 2.5 mm. Wouldn't hurt to look at the sites of TR Enterprises and Racetorations also.

Using the data in Section P2 of the Technicalities CD (an article which I published in Newsletter 13 - the early dawn of the TR Register!), then it should be possible to calculate the thickness of gasket(s) required to achieve the desired CR.

Ian Cornish

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Hi every one, I do not usually post on the forum but having read this thread, i thought you may be interested in my winter project. I have a right hand drive 1962 TR4 which went from the factory to Australia and returned to the UK in1977.Had 3 owners but has been not used for the last 15 years. Currently the body shell has been soda blasted back to bare metal and is awaiting painting, the engine is stripped, block has been acid dipped and new cam bearings fitted, the head is at Anderson Racing Engines having new guides, unleaded inserts and larger exhaust valves. The crankshaft is being balanced along with a TR6 clutch and light weight fly-wheel, the cam is a special grind from Kent giveing .410 lift and a 34 degree overlap. The engine should have a compresion ratio of around 8 to 1, using dished forged pistons.

The Moss supercharger kit arrived this week, it has taken about 5 weeks since being ordered . Mean while i have been collecting all the rest of the kit i intend to fit, the car already has 4 pot callipers on the front and twin pot on the rear. the rear calipers are from a Fiat 125 and incorperate a self adjusting hand brake. Both sets of calipers have been rebuilt by Big Red ,in Worcester, there is a LSD diff fitted and a Ford type 9, 5 speed gear box, which is currently being rebuilt .

I am fitting the TR6 brake pedal box and servo. The air filter which comes with the s/charger is four and half inches long, i intend to remove it and use a 90 degree alloy 52mm pipe from the S U carb to go across the back of the engine and down the 'cooler ' side of the engine to the radiator shroud and fit an air filter there. I have the AEM methly water injection kit and intend to fit the injector into the alloy pipe up stream of the carb. A 123 Tune dizzy will be used in conjunction with the water injection to prevent detonation. I am expecting to get the painted body back in November, and then the fun begins!!

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Hi every one, I do not usually post on the forum but having read this thread, i thought you may be interested in my winter project. I have a right hand drive 1962 TR4 which went from the factory to Australia and returned to the UK in1977.Had 3 owners but has been not used for the last 15 years. Currently the body shell has been soda blasted back to bare metal and is awaiting painting, the engine is stripped, block has been acid dipped and new cam bearings fitted, the head is at Anderson Racing Engines having new guides, unleaded inserts and larger exhaust valves. The crankshaft is being balanced along with a TR6 clutch and light weight fly-wheel, the cam is a special grind from Kent giveing .410 lift and a 34 degree overlap. The engine should have a compresion ratio of around 8 to 1, using dished forged pistons.

The Moss supercharger kit arrived this week, it has taken about 5 weeks since being ordered . Mean while i have been collecting all the rest of the kit i intend to fit, the car already has 4 pot callipers on the front and twin pot on the rear. the rear calipers are from a Fiat 125 and incorperate a self adjusting hand brake. Both sets of calipers have been rebuilt by Big Red ,in Worcester, there is a LSD diff fitted and a Ford type 9, 5 speed gear box, which is currently being rebuilt .

I am fitting the TR6 brake pedal box and servo. The air filter which comes with the s/charger is four and half inches long, i intend to remove it and use a 90 degree alloy 52mm pipe from the S U carb to go across the back of the engine and down the 'cooler ' side of the engine to the radiator shroud and fit an air filter there. I have the AEM methly water injection kit and intend to fit the injector into the alloy pipe up stream of the carb. A 123 Tune dizzy will be used in conjunction with the water injection to prevent detonation. I am expecting to get the painted body back in November, and then the fun begins!!

Excellent !! That 8:1 compression should allow you to use the higher boost option ( ie pulleys) that Moss offer, on 97RON or better.

Should be ready for IWE Lincoln then?

You have PM.

Peter

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Easter !....... I shall still be hibernating... :unsure:

 

Peter

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Looks as if you're ahead of me in the build process, still collecting parts at the moment, and haven't purchased the blower yet was hoping that it would be in the 17percent off Moss sale but sadly not, had to settle for the roller rockers. Did you get JE to make the dished Pistons? Would like to know the spec. Look at the U.S. Moss website, they offer an even greater boost upgrade than the puny European version , also if using the 123 tune dizzy would look at fitting a knock sensor so if knock is detected the dizzy can switch maps and save you lots of money, I wish someone could save me money, at the moment it feels like my Healey v8 build all over again

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J E forged pistons, flat dish .071 depth, short skirt type, when the head has been cc'd i can then get the right thickness copper gasket to give the 8 to 1 c/r. i will start with the lower boost pully and see what

that is like and maybe move onto the larger pully after the engine is run in and every thing is beded down. The 123 Tune dizzy has a 'boost retard funtion' which ,i think , is a way to set the ignition to retard at a given RPM and to

start the methly water injection, which should reduce the risk of knock.

have not had time to fully read all the information on it yet

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J E forged pistons, flat dish .071 depth, short skirt type, when the head has been cc'd i can then get the right thickness copper gasket to give the 8 to 1 c/r. i will start with the lower boost pully and see what

that is like and maybe move onto the larger pully after the engine is run in and every thing is beded down. The 123 Tune dizzy has a 'boost retard funtion' which ,i think , is a way to set the ignition to retard at a given RPM and to

start the methly water injection, which should reduce the risk of knock.

have not had time to fully read all the information on it yet

Tony, Are you certain the 123 boost-sensor is going to continue to give correct timing if it gets contaminated with condensed fuel, or water or alcohol? On modern boosted engiens the sensor see only air, no liquids.

Peter

Edited by Peter Cobbold

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Peter, as far as i know, and i have not fully read all the instructions yet, the dizzy can be mapped via soft ware on a laptop, and you set the RPM point at which you

want the ignition retarded, so at say 4000 the timing is reduced to 28 degrees advance in stead of 30

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Tony, Are you certain the 123 boost-sensor is going to continue to give correct timing if it gets contaminated with condensed fuel, or water or alcohol? On modern boosted engiens the sensor see only air, no liquids.

Peter

Thats why they say to use the flame trap type of sensor pipe and have it come up to the dizzy.

Stuart.

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Peter, as far as i know, and i have not fully read all the instructions yet, the dizzy can be mapped via soft ware on a laptop, and you set the RPM point at which you

want the ignition retarded, so at say 4000 the timing is reduced to 28 degrees advance in stead of 30

Yes, that appears to be ideal. But the sensor may be affected by liquids getting into it. I would check that it is safe with 123 themelves. Check with them that when it get wetted the timing doesn't go too advanced ( engien will knock) or too retarded ( preigntion melts pistons).

Peter

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Thats why they say to use the flame trap type of sensor pipe and have it come up to the dizzy.

Stuart.

Stuart, Yes. I think that will be fine with normal engines.The problem is the s/c boost is hot , 40-80C, and liquids will condense in the cooler flame trap. Over time it may well fill up with condensate.

I know of one piston-melting incident on an s/c engine fitted with a 123tune. No proof, only a suspicion.

Peter

Edited by Peter Cobbold

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Peter, as far as i know, and i have not fully read all the instructions yet, the dizzy can be mapped via soft ware on a laptop, and you set the RPM point at which you

want the ignition retarded, so at say 4000 the timing is reduced to 28 degrees advance in stead of 30

Tony, You can set the boost to give few degrees retard, as well as the rpm advance ( its digital 'centrifugal advance'). You need both, since 4000rpm at steady speed eg on motorway wont produce boost. Boost will only appear at, or close to, wide-open throttle.

But you may not need boost retard with the 6psi boost pulley, given you have 8:1 compression, on 97RON or better. Because effective compression will be ca 9.5:1 at 6psi.

When you fit the 9psi 'superboost pulley you will need to take antiknock measures.

Water injection can also do the same job as boost retard, I doubt you'd need both.

Peter

Edited by Peter Cobbold

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As Peter says knock is a piston killer, stay on the water injection idea as you will loose power with boost retard and check out the Phormula KS-4 knock sensor kit as a failsafe

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Peter, Stuart,, i am not sure what sensor you are refering to, there was nothing resembling a sensor in the 123 Tune box, just the dizzy, and the information regarding mapping for '' boost retard'' What am i missing /not understanding here?

tony

Edited by Tony

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Deano, i have looked at the Phormula KS3 / 4, clever kit, i will keep it in mind for when the car is up and running next year.

tony

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