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Whats the BHP


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As some of you know, at one of the recent challenge events I had an issue with the engine ………… a stone punctured the timing case and a considerable amount of silt got into the engine ……… curtains to a 190bhp 3.5EFI…. :rolleyes:

Very quickly I acquired a 3.9 and over the last month have been gathering the parts for a mediocre rebuild ……………

Currently sat in the ‘office’ I have the following parts ………… I was going to post a pic but the camera is also not a happy bunny………. <_<

Forged KB pistons

Moly-Chilled Iron Rings

Comp Cams Cyclone

Cleavite Tri metal bearings (similar to Vandervell)

Rhoads Lifters

Moly Crome rocker Shafts

OEM Rockers

ARP studs for both bottom and top ends

Non binding valve springs

Cloyes true roller chain timing gear with 4 degree offsets

Also I have just collected the machined parts that have been finish to my specification……….

Block:

20 thou rebore with a honing accuracy of better than 1 thou over the entire bore length (yes, the machinist thinks I am a fussy bar steward :rolleyes: ), new cam bearings and main bearing housings line honed. I really wanted the block decked by 15 thou, but this was proving too difficult in terms of the set up required to keep the centre line of the block as the reference point……… so we took extras from the heads

Crank: 10/10 regrind and balanced

Heads: Planed by 50 thou and new guides

Rods: Balanced and pistons fitted…………I wanted Carrillo rods but £1200 a set was a bit out of line :blink:

During the engine build I will port and flow the heads (about 2 weeks work)………………..also I will advance the cam timing by 4 degrees to increase the low end torque. The build will be ‘a very careful build’, but I will not build to blueprint standards as my experience tells me that the gains Vs effort are not worthwhile. However, much effort will be put into those area’s where the true gains are to be made…..

The jury is out as to whether or not a paddle clutch will be required…………

EFI will be Megasquirt and ignition is EDIS………………….

I’ve already done my sums ;) ………… and I will confirm these on the rollers at a later date…………

In the past I have seen ridiculous figures claimed for engine power (yes, even here)…………. :rolleyes:

So, lets see how well some of you know your engines …………. What’s the calculated BHP ? …………

:)

Ian

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Hiya,

For my guess I would say 225 - 230 BHP, but you'll find with the cam and Rhodes lifters you'll have a very grunty "tractorable" engine, don't forget the exhuast can make a huge difference ?...what is it at the mo ?

BHP is not everything, power and grunt can make a high reving cammy motor seem low on power even tho its higher !

Nige

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Hiya,

For my guess I would say 225 - 230 BHP, but you'll find with the cam and Rhodes lifters you'll have a very grunty "tractorable" engine, don't forget the exhuast can make a huge difference ?...what is it at the mo ?

BHP is not everything, power and grunt can make a high reving cammy motor seem low on power even tho its higher !

Nige

Yes, you are right of course ..............but max bhp will always be at max rpm ............ torque is vastly more important and I am trying to keep the power band as wide as possible and starting as low in the rev range as possible. By using the combination of the above parts and advancing the cam timing, I think the low end grunt will be impressive.

The exhaust breathing is what JE always considered to be the best ........... the early EFI cast 4-3-2 with 2-1 down pipes........... if you remember he created a large bore version of this exact manifold for the lager capacity engines. Tubular headers would not help the low end grunt

Whats the calculated HP to ££££ ratio and does it raise expotentially in relationship to the SWMBO effect, when she finds out :D

Its OK les .............. she knows ...........

:)

Ian

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Mr Eales still does them too :

"Exhaust manifolds £380.00Large bore cast iron exhaust manifolds. The ports are approx. 37mm x 28.5mm and the downpipes are 46 mm. The manifolds come with a mating steel flange for the downpipes."

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V8 Porn at its finest :D

Nige

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The potential power of a rover v8 through heads with an inlet valve size of 9,048 sq mm i have calculated to be 302bhp

however this is running at 100% VE (or hihgher with pulse tuning)

I reckon you are going to be making 241.5 bhp and 295lb/ft at 4300rpm.

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pls excuse the spin-off question...

I fitted a adjustable duplex chain kit to my stock 3.5 a while ago. set to 0 deg.

Would an advance help my low end torque on a stock 3.5?

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pls excuse the spin-off question...

I fitted a adjustable duplex chain kit to my stock 3.5 a while ago. set to 0 deg.

Would an advance help my low end torque on a stock 3.5?

If it was a standard EFI cam (either 3.5 or 3.9) then probably not ..................... a lot of factors come into play when adjusting the cam timing.......... zero is safe!

:)

Ian

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When I had the eales apart for a rebuild it had a BEAUTIFULL Vernier timing gear with duplex chain, when I looked closely at it it had 3x blobs of weld on it :huh::blink:

I phoned up Mr Eales and asked why ? :unsure:

"Simple" He said "stops people like you taking them apart, then phoning me up saying 'It won't start' " :lol:

Fairy nuff, left it alone

Nige

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Well those that have posted are overall pretty much on the money…………

My calcs go something like this……………….

Std 3.9 = 182bhp

The cam has dyno documentary evidence ……….

Cam + cloyes true roller timing gear is worth between 28 & 32 …. So I’ll call it 30bhp

Ported and flowed head using standard valves is worth up to 40bhp ………… but I don’t have a flow bench so I’ll call it 20bhp

Aftermarket ignition & Fuel injection (EDIS / MS) is worth another 15bhp

Inlet manifold port matching and flowing is worth up to 20bhp ……… again without a flow bench I’ll call it 10bhp

I haven't factored in raising the compression ratio .............. for me that just aids the breathing.......

So…….. that comes out at 182 + 75 = 257 …………..with a potential of 280ish if every thing is perfect ………..

However, nothing is perfect in this world so I’ll go for a sensible figure of 230/240ish……

Over the weekend I made a start on the heads ………. Ali is easier than cast steel but its still a soul destroying job ……….. <_<

This is how far the ports need to be enlarged .......... the center ports have been roughed out to size and the right port is standard

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All the ports now opened and prepared for finishing

gallery_269_31_19410.jpg

Then we open up the inlet valve throats to within a mm of their lives.................

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coming along nicely now.............. :D

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then comes the inlet manifold ............ 2 ported and one standard to show the size difference..

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how much material is removed .............. this was swept off the bench and there is probably more than this on the floor.......... :rolleyes:

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Dont underestimate the work required here ................. the above represents a good many hours..............

The inlet and exhaust tracts will not be polished (like I used to do in the dim and distant past) as modern flow benches have proved that the gain by polishing is about 1% over the blended ground out finish .......... (thanks to HFH for pointing in the right direction with regard to the polishing) ;)

:)

Ian

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VERY NICE WORK IAN

I AM TOLD THE RINGING IN YOUR EARS WILL GO .......EVENTUALLY :lol:

Have you thought about matching the cast manifold exhaust ports to the gasket to the head exhaust ports whilst your at it ?

TVR do 'bigger gaskets' than std .........as do Eales ...............for not much money.................

Just a thought, but you've probably had enough of it by now :lol:

Nige

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:hysterical:

V8 Porn at its finest

ARGGGGGGGGGGGHHH

LOOK OUT

................Oh.................Too Late

More V8 Porn

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Going onto mine shortly :)

Bought 'whilst dribbling' and getting my £s out (ooer missus :blink: )

........I've not done 'DIY' (a la BBC) by me I hasten to add :P

Reckon with Ians Head porting if he fitted this Dogs Cats and small shrubs ......even small innocent children, trying to hold on to their mummies hands on their way home from school, could be sucked up inside his new V8, complete with their satchel and empty lunchbox as he drove along, .....hence why he can't have any of it -

A H&S move by me :hysterical:

Nige

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Here is a good reason why port matching needs to be done………..note the casting offset when the ports are matched ….. :blink:

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Here is close up of the material that has to be removed…..

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Then the finished manifold……….

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I did consider taking out the trumpet base from 38mm to 45mm ………… maybe at a later date.............. nige, you're a bad man :lol:

:)

Ian

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Ooh... :)

I'm planning on doing pretty much this with the pile of bits in my loft that was once the original 3.9 from my range rover - although if I ever get round to it I'll probably just end up trashing a perfectly good engine :huh:

I shall be watching closely for ideas to nickinspiration :lol:

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A little more effort was put in tonight ………………the bolting together of the engine only takes hours………….. the preparation takes days :rolleyes:

Now the heads and inlet manifold are completed, attention is now focused on the block

Andy (the guy that does my machining) has made a cracking of the bores and the final hone marks are clearly seen. Two hours were spent ensuring the bores are parallel and they are well within 1 thou over the entire length of the bore.

gallery_269_31_34777.jpg

Next job is to grind out the casting flashings in the lifter valley to encourage good oil drain back to the sump…………. about 2 hours work

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I do a small modification to the block. A 5mm hole is drilled on one side of the valley to allow drain back to the sump via the timing gear. Many tuning shops drill 2 holes (one either side) but I have found it OK to just use one hole on the left of the block as this is an oil trap ………… the right hand side readily drains.

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Then more time is spent inspecting the block in minute detail. Each and every hole is inspected and if the thread looks at all iffy then it is marked for further attention. Even the block drain plugs are removed and the water passages inspected with flexi lights and mirrors. Also the core plugs are checked for integrity. One area of slight concern is some coolant corrosion on the block face…………. <_<

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This is not too worrying as this area sits underneath an open water port on the head. Also the area around the bore is OK to get a perfect seal. However, I will repair this to ensure the gasket has a good solid base.

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Repair is easy ………. a smear of JB weld. Tomorrow I will sand this level with the block face and true it off with a start edge. ;)

gallery_269_31_4121.jpg

:)

Ian

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Next part of the pre-assembly process is to gap the rings. Here I am looking for 3 to 4 thou per inch of bore. If the bores were worn then I would gap them at the lower end of the bore (less wear), but I have checked the machining on these so the top is OK.

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A couple were a little too tight for comfort so needed a little iron removed from the end of the ring. The only tools you need for this are these …… a small stone and a fine warding file…. Once gapped all the rings are tagged ready for fitting to the pistons.

gallery_269_31_35099.jpg

Next job is to check the running clearance of the main bearings and big ends. First off we fit the bearings dry and torque the cap……..

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Then we measure the crank journal……………

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A simple calculation gives the running clearance …….. in theory the bearings are separated from the journal by a layer of oil …… hence the clearance tolerance. In my case I am looking for 0.5 to 1.8 thou on the mains and 0.5 to 2 thou on the bigends.

These are all good but if adjustment was needed I would lightly hone the housing as the bearing is sprung loaded in the housing. With the bigends, provided you are fitting new pistons then the rods can be swapped around to get the best fit.

Once every thing measures out OK the rods are then stamped ………..

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The MB caps are already factory marked………..

Just to keep HFH happy ;) , these are the bearings ……..

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:)

Ian

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Hmmmm

Very interesting thread this Ian -

To my knowledge no-one has ever actually posted a how to build your V8 up thread,

so I reckon this will end up in the tech archive,

your doing a more than carefull job, and many would shortcut,

and shortcuts are not a good idea on engine building for the best possible result..... :unsure:

However, even after the phone call tonight I am still stunned and comment as below :

. Two hours were spent ensuring the bores are parallel and they are well within 1 thou over the entire length of the bore.

I seriously think you need either help, or to get out more - or both :lol:

Whilst commendable your are not building the next NASA rocket - ................or are you :)

Next job is to grind out the casting flashings in the lifter valley to encourage good oil drain back to the sump…………. about 2 hours work

Proper work !

I do a small modification to the block. A 5mm hole is drilled on one side of the valley to allow drain back to the sump via the timing gear. Many tuning shops drill 2 holes (one either side) but I have found it OK to just use one hole on the left of the block as this is an oil trap ………… the right hand side readily drains.

Eales does 2, and others do as you have one,

both have a HUGE efect on oil, ,,,,,,,,,,,,,gawd knows why the factory haven't cottoned onto this tuners tricks....

Then more time is spent inspecting the block in minute detail.

Each and every hole is inspected and if the thread looks at all iffy then it is marked for further attention. Even the block drain plugs are removed and the water passages inspected with flexi lights and mirrors. Also the core plugs are checked for integrity. One area of slight concern is some coolant corrosion on the block face………

Concern for you, and possibly your wife ?.

Please fit the conrods and pistons. Please FFS

I understand your 'teddy at bed time' has been replaced by a Block Pistons and Rods,

.....you may argue this is normal, ......its not, .........this is "On the fringe" ...........and you need help Ian :lol:

Repair is easy ………. a smear of JB weld. Tomorrow I will sand this level with the block face and true it off with a start edge. ;)

Were you a vernier in a former life ? :lol:

Next part of the pre-assembly process is to gap the rings. Here I am looking for 3 to 4 thou per inch of bore. If the bores were worn then I would gap them at the lower end of the bore (less wear), but I have checked the machining on these so the top is OK.A couple were a little too tight for comfort so needed a little iron removed from the end of the ring. The only tools you need for this are these …… a small stone and a fine warding file…. Once gapped all the rings are tagged ready for fitting to the pistons.

Gapping is so importnat, many people just assume the ring are "OK" as new and fit.....

Just to keep HFH happy ;) , these are the bearings ……..

gallery_269_31_21691.jpg

Mmmmmmmmmmmmmmmmmmmmmmmmmmm V8 porn at bedtime - Christ I am getting as bad as you :hysterical:

Seriously a Really great job and useful thread, look forward to the next update

Nige

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Yes, I guess it’s sad, but I used to build A series race engines and you leave NOTHING to chance when they are to spin at 9K. Also my father was a precision engineer through out his working life ………. Verniers, Micrometers, dial gauges, and ground straight edges were a way of life in our house ………. I guess it rubs off.

Next steps are to fit the crank and then measure the piston to deck heights……... years ago I would then have stripped it again and machined the pistons to match the lowest ……….. then comes the fitting of the cam and ensuring the valve timing is correct to within a degree or so ……. I know………….sad, sad ,sad …………. :lol:

:)

Ian

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May I contribute my 2 pence worth and suggest that forum members have a whip around to put Ians truck on a rolling road Dyno to get definitive horsepower and torque figures. I still cannot get my head around some of the numbers some members claim whilst still retaining LT77/R380 gearboxes.

Bill.

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Bill ……….. :hysterical:

Have no fear …………. I have 4WD rollers within 30 miles of me and once it is run in, then on the rollers it goes ;) ……. and I will post the printouts ………

The G/box is an LT77S Def V8 version, built up for me by Dave Ashcroft (ashtrans) some 40K miles ago……….. it survived OK with 190bhp of 3.5,but its not the end of the world if it dies as they are fairly easy to fix…………….

:D

Ian

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Yes, I guess it’s sad, but I used to build A series race engines and you leave NOTHING to chance when they are to spin at 9K. Also my father was a precision engineer through out his working life ………. Verniers, Micrometers, dial gauges, and ground straight edges were a way of life in our house ………. I guess it rubs off.

Next steps are to fit the crank and then measure the piston to deck heights……... years ago I would then have stripped it again and machined the pistons to match the lowest ……….. then comes the fitting of the cam and ensuring the valve timing is correct to within a degree or so ……. I know………….sad, sad ,sad …………. :lol:

:)

Ian

Ian, as 'sad' as it may be the results will be excellant!

Bill, Ashcrofts do quite a few improvements to LT77's / R380's. They'll even do a build using TVR spec internals for not that much money. If you get really silly then you can go to Rakeway who'll sell you a 'box that's a straight swap for an R380 but is safe to 600 lb/ft but its far from cheap!

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A little more was done over the weekend ……………..heres a bit more to bore :lol: you all with..........

With most of the pre-assembly measurements done, this contraption now stands half a chance of bolting together correctly

First up is to clean all the oilways in the block and crank to make absolutely sure there is no machining debris or other carp in them. Don’t skimp on this procedure……….. it took me the best part of a day........... yes about 7 hours.....

For this work I use a bore snake…………………..

Bore snakes are used for cleaning rifles ……. Rimfire. CF and airguns……. The kit contains two snakes, brass brushes for .22 & .177 calibre, cleaning wads, and some quite nasty solvent (we wont use that here). The brushes screw onto one end of the snake and the wads clip onto the other end.

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This together with a good dose of brake cleaner does the job ………

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The wads do a good job of pulling any carp out……………..

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The whole point of the brake cleaner is that its an air drying solvent and will leave the oilways dry ……….. important because they all need to be blown out with the airline to ensure that they are absolutely clean ………….. the last thing you want os a rouge brass hair front the brush left in a gallery…………

One its all been cleaned and air blasted the main galleries should look this clean ………. This is the main lifter gallery on the odd bank….

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Next is the crank fitting ………… first the upper shells are placed ……….

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As this engine will be another 2 weeks in build, I am using ver liberal amounts of bearing guard ………. This is a specially formulated build lube based on Extreme Pressure oils (EP) ……… this stuff is real thick and sticks like sh!t to a blanket…..

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Once the crank is in, then its time to fit the caps ………. Again, cleanliness is paramount here……..make sure the bearing shell surface is clean as any cr@p here will destroy the running clearances that we have been so careful about earlier.

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The caps are numbers with arrows that point to the front of the engine ……… simple…..

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The bolt should be oiled before fitting …….. I use a mixture of 60/40 EP90 & paraffin. The paraffin is to lubricate (remember … the block is ally) and the EP protects. This has always worked well in the past for me.

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Once the correct torque has been applied to the bolts (the end cap is more 20NM than the others) it time to measure the crank end float. This must be measured at the centre main bearing thrust face. Here I am looking for between 4 and 8 thou…….. this is measuring 5 thou …. Very pleasing…..

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If the end float was wrong and the thrust bearing measures OK then the only real way out is to discard the crankshaft ……….It can be welded and the trust faces reground, but this is an expensive option.

The crank now spins very free ……..excellent.

If the crank was stiff……… because all the clearances have been checked there are two options ……. A distorted block or a bent crank (both are not unknown)……… in my case I checked the block for distortion before I fitted the crank. Rover V8 cranks have been known to bend ….. you only need a couple of thou ……..

Dont go away folks ............ there is more to come

:)

Ian

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I guess the next job is to fit the pistons…………….

Just to recap …….. When I got the machine shop to press in the gudgeon pins, I also got then to balance out the weight of rod and pistons ….. i.e lightest piston with heaviest rod etc……….also when I measured out the bigend running clearances the rods were number stamped for final fitting…………

First comes the fitting of the rings …………. The most important first step is to check the ring groove clearance ………..here I am looking for between 2 and 4 thou ………. These are all 2 thou ….. just the job.

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If the ring gap was too tight then check all the rings for equal thickness ……..if that checks out OK , then break an old ring and gently run the broken edge around the ring groove to clear out any burrs or carp ……. HEALTH WARNING ….. use gloves as old rings are sharp….. very sharp ……. Usually 100K miles honed sharp ………

If the rings were too slack then discard the piston …………..

I guess at this point I should make a mention about the positioning of the ring gaps …….

The oil control ring is upper and lower rails with a spacer in between ……. The rail gaps should be a couple of inches apart otherwise the piston will pump oil …….. the compression rings are then turned so the gaps are on opposite sides of the piston and that they do not line up with the oil ring rail gaps……………. Also make sure the rings are the right way up ………..

Next the fitting of the piston into the bore ……………make sure the bores and piston are well oiled with a quality oil………..

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But before sliding it in the bore ……… make sure it’s the right way round………

The rod and cap has a pip on each ………. like so…..

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The pips indicate that the cap is fitted correctly and also the pips of the rods on each shared journal must face each other

Then fit the shell and coat with build lube before applying the correct torque…

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I always fit one journal at a time (one even and one odd piston)

Once fitted then its time to check the end float of the bigends ……… here I am looking for 6 to 14 thou ………….. these came out nicely at 8 thou…..

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Then just repeat the above 3 more times ………………………..

Once all the pistons are fitted, its time to check the deck heights. This is very important on high reving engines, maybe not so important with this application …….. but I’m going to check it all the same………

What we need too know is the piston crown the block surface gap ….. the closer the gaps, then the more even the compression ratios. The things that determine this are the build tolerance of the rods (4 thou between centres) and the quality of the pistons.

Bring each pot up to TDC with a dial gauge and place a ground straight edge across the pot ……… then measure with a feeler ………..these all came out at between 40 & 41 thou…… very, very pleasing ………expensive pistons are worthwhile…..

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If the gap varied a lot (more than 3 or 4 thou) then subtract the height of the highest from the lowest and have the block face machined by that amount, then have the piston crowns machined to the height of the lowest…………. Here we are talking high revving race engines…….but it is still good to do and understand………and I know that all mine are within a thou or so.

This is the build lube even after 24 hours ………..

gallery_269_31_49565.jpg

:)

Ian

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