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The dropped spindle affects another steering factor in that you can tune the position (height) and change (increase) the "angle" of the modified steering arms position relative to the spindle`s straight ahead position) to increase the Ackerman angles, to make both front tires effective in cornering rather than the inside wheel offering no "positive" slip angle to the road`s surface. Commonly it`s just along for the ride. With the "dropped & lengthened upright improving the inside tires contact patch it should be used. (Commonly you see race cars with the inside tire/wheel at a severe neg camber angle with nothing but the inside edge of the tread being drug through the corner)
Richard
Would you be willing to go into more detail on this? I'm running dropped spindles on my Alfetta, as you note the max drop with 15" wheels is 1". The lower Arm is level but the I would like to lower the car more which of course will have the negative effect of making the lower A arm higher at the spindle end. How do I then make the correction to get the proper Ackerman to improve the inside tires contact patch?
Thanks
 
Discussion starter · #23 ·
Steering arms

They can be heated and bent, but you need to see how much is needed before doing it.
 
Discussion starter · #24 ·
Piston mods and compression ratios

This question came from a friend in Sweeden..

In a message dated 8/28/2014 7:59:44 A.M. Central Daylight Time, Perxxxxxxx@sodexo.com writes:
Hi Richard.

I’m about to repair a spare 2L motor with Borgo 10;4:1 pistons. One liner is rusty and one piston is frozen after a head gasket faliure. I will change the rings, put in another good used liner and cut the head, and while all this is apart:

I have seen in some picture that you have cut the top of some 10.4:1 pistons in order to lighten and improve combustion.

How much did you cut the piston?

In order to get the right compression in a motor with cut pistons and a RJR 221 /Shankle exhaust cam combo, how high should the head be after cutting?

Best Regards
Perxxxxxxxx
-------------------

Per... What is the compression ratio you are shooting for after the rebuild?

First the pistons. The old 10.4 Borgo pistons don`t have the additional metal around the sides of the dome to close up the squish area as was designed into the 10.0 to 1 Motronic pistons(which are closer to about 9.8), or aftermarket race pistons which are the one`s we cut to get lower CR using them in a street motor.
In fact the "10.4 designation was optimistic at best, and closer to 10.2 in a uncut stock head. Still, when these were popular it was a good improvement over the stock 9.0 to 1 stock pistons.

I would only suggest cutting 1mm to 1.5 mm from the dome. But you can cut away 15mm easily from the bottom of the piston skirts to lighten them. Knurl around the skirt afterwards to swell the metal and create a oil retaining area. This is a good idea any time you are reusing pistons/liners to control piston side to side movement which unseats and causes rounded ring wear.

Have you considered finding a used set of Motronic pistons since you obviously are building this on a budget? You can lighten these by skirt cutting (and knurling) as well.

There`s little reason to shoot for less CR than 10.5 and commonly I try for 10.7 on street motors with our max 92 octane pump gas.

The "Head Milling" I suggest below is based on cutting a stock thickness head (4.410 / 112.2mm ? ) to get to about 10.5 to 1 CR.

--With the unmodified 10.4 Borgo piston domes cut the head .025 (.6mm)
--10.4 Borgo dome flattened .050, cut the head.040 (1mm)
--Using Motronic pistons cut .040

If your fuel available is higher than ours and you want to shoot for a better CR than 10.5 the head can be cut more to get there.
 
Discussion starter · #25 ·
Race engine problems and TS considerations

Rather lengthy, and some info might aggravate, but as Jack Webb said, "only the facts mam"

Dear Richard,

I allways read with interest your comments on the AlfaBB concerning engine preparation.
At the moment I run a Nord with 85mm JE pistons and EFI (DTA computer , Jenvey ITB).
Since this engine is at the border of its power, and we have regular problems with it I am contemplating building a TS .
I would like some advice on cams, and headwork to be done (or not to be done...). The cams you design are working nice (a fellow racer has them in a nord and is very happy with them).

Hope you can take some time to inform me, it is for a full race engine.

Regards,

Walter xxx xxxxxxxxxxxx
The Netherlands
In a message dated 8/28/2014 10:30:34 A.M. Central Daylight Time, AlfaR7@aol.com writes:

Walter,
Some questions, but I also have to think you might be missing the point by considering building a TS after all the extensive work done on your Nord motor.

I and all, know well the "advertised" power being made by certain British builder/supplier. However these expensive engines checked on "honest" and "calibrated" dynos by unquestionable builders here in the USA are only making about 85% of the "guaranteed output".

Not knowing your internal build info, or problems with the Nord I wouldn't jump into that without serious thought.
What are your problem issues with the Nord? What are the internals? Head mods and cams used? What HP are you getting on your dyno?

About the only thing I would want from a TS is the crankshaft from a 155 to get the longer stroke. This will fit in the Nord block.

As for TS cams I would suggest the RjR575 intake and RjR1291 exhaust. These will require head mods to clear the lift including short guides set deep, race springs, notches to clear lobes in the cam follower bores etc. Smoothing out the intake runners and reshaping the seats will improve flow, however don`t get caught up in the large intake valve, small exh valve mods.

See attached PDF file of full lobe profiles.

A successful race engine isn`t about high RPM power, It`s about power made over a useful power band to make an easily driven race car.

If you are having issues because of high rpm failures, you will have the same with a TS.

Rj
---------------------------------------------------------------------------------------------------------------------
Hi Richard,

Problems we had are somewhat related to overrevving , own fault, but issues with leakage test since. Engine is now apart, almost in the car again and will be dynoed in the next few weeks.
Internals are a knife edged crank, 85mm HC pistons (spruell supplied these), H beam rods, 45 mm intake valves (reading your comments we shouldn`t have bothered) also Spruell, as are his valve springs, highest rate he has. stock exhaust valves
CB cams intake 12.9 lift and exhaust 11.3 (diagram I have not at hand at this moment).
Long aluminium intakes (Alfaholics) and off course the DTA EFI.

Rear wheel HP when engine was just run in 171 at 7000 rpm`s, torque 180 nm also at the wheels, I do however not have the dyno print at hand now for the curves.

Reason I am contemplating on a TS is that engines (especialy the 155 and 164 2nd series which also has the 90 stroke crank) are more available overhere than a 105 2 liter, and I am building a FIA car (GTAM replica) that can get the 2 liter fitted, with carburators (I have 45 mm dell orto with 36 venturi).
I will need in the end a second engine when that car is finished (almost on its axles by now) and have to go from scratch, no spare parts to mention.

I am told by several engine builders the 155 block is stiffer than earlier blocks, with also stronger main bearings (I am aware of the tales AH , Formula GT and so on tell on HP , but I also know I am with my current engine just as fast on Castle Combe, their home and main testcircuit as Max with his 215 HP TS). And torque on any TS I seen and drove, and experienced has way better torque at lower rpm`s , better on the more twisty tracks overhere than just the high HP at high RPM.

I appreciate your thoughts on this.

Regards, Walter
---------------------------------------------------------------------------------------------------------------
Walter,
Several things caught my eye.

The knife edged crank to start.
Alfa Nord 2 Liter cranks have inadequate weight in the counter throws to correctly balance an engine for use over 6000 RPM even with light Carillo rods and light pistons. Knife edging compounds the problem.
If you are having crank/bearing issues blame the knife edging. (I do assume the block has been drilled for direct oiling on #2 & #4 main. If not it should be.)

There are light billet 2 liter cranks being made by Marine in Calif. Will send you an email with the info. These light cranks have adequate designed counterweights for higher RPM use.

The camshafts. I am unaware of any 12.9mm lift cam made by C&B for any Alfa. None at all on their website. Never heard reference to such.
Regardless the C&B`s typical designs are high overlap designs and the exh cam has to be another C&B "intake" cam by design and incorrect for the exhaust side.
Correct cams will both make a more powerful motor and do it at reasonable RPM. As well the power band will be much larger/longer. Again those cams I suggested for the TS are what the serious engine builders over here are using. There are no TS cars (even the 2 with AH motors), running competitively against well built Nord motors. Typical baseline rear wheel HP on these is 190 and above....

If your head hasn`t been "High Ported" it should be. See my intake at post 179 at:
http://www.alfabb.com/bb/forums/motorsports/146464-old-alfa-racer-pics-so-west-div-4.html

Don`t use Delorto carbs. They won`t flow as well as Webers. As well you should use 48mm carbs if racing with carbs at a minimum. I`m using to 50 DCO carbs but they require a custom manifold due to width.
48mm DCOEs can be modified at the middle shaft ends to fit a stock Alfa intake opened up to fit big runners.

The "Torque" you mention is not the TS design, but cams being used. Those are the engine`s brain. (As well the engines are most likely using the longer stroke crank, legal or not...)

What is the Throttle body size? Shouldn`t be any smaller than 45mm and preferably larger. Hopefully fed from a cold air box, not airhorns in the engine compartment.
Rj
---------------------------------------------------------------------------------------------------------------------

Hi Richard, thank you very very much for putting me back on my feet concerning the possibilities of the old nord engine.


Few question still :
First price of the camset as you adviced?


Second the crank, you know a price of the firm you mentioned? And the 90mm crank 155, use eith its own shorter rods to prevent protruding pistons? Or use longer nord rods with changed piston pin location?
And last what is your opinion on the " apple bite" pistons from Spruell?


O and one more: do you plan any CR gearboxes in the near future, might be interested in one if shipping to holland is no problem for you?


Regards Walter
---------------------------------------------------------------------------------------------------------------------
Walter,
-Cams (a pair of any lobe design) shipped to Europe is $xxxxx USD.
I keep a pair of the RjR575/RjR1291 cams in stock because of demand. If you catch me out of stock build time is normally about 2-3 weeks, but I order as soon as stock ones are bought.

-Billet Crank by Marine. I don`t know for sure but I think it`s about a $3,200.00 item. Jon Norman, Alfa Parts, Berkeley, Calif. is the Distributor (ALFA PARTS - Alfa Romeo Parts, Spares, Accessories 800-890-ALFA)

-155 crank : I think using it and the 155 rods would fit on your pistons.

-The Apple bite Pistons. I`m no fan. I bought a set and they measured 84.5mm at the skirts!! Had to bore new liners to fit as skirt clearance was .024 (.55mm) in the 85mm liners. I`m not the only one with size issues with these pistons. See Bill xxxxxxxxx`s mail I cut and pasted below.
In my opinion (?) the dome design is good for fitting in a 2 liter Nords 4 different shaped combustion chambers, but the "applebite" and with the really big valve reliefs are not appropriate re compression increase. And that's why they only produce about 11.5 CR in a full thickness head.... If the existing uncut dome design was simply flat cut about .050 off the peak, and valve reliefs sized correctly and not as deep they would be more effective. The dome of the pistons will still fit a head (that is stock thickness 4.410") with .020(.5mm) milled off of it to improve the combustion ratio.(to 4.390 thick )

-I keep at least one CR box built on the shelf. Right now there are two. Both with the rear tower shields to prevent spray into the shifter tower.

One is a 1.99/1.59/1.25/1.0/.92
the other is a 1.85/1.59/1.25/1.0/.92
Cost $xxxxxx complete box or gearset complete with syncros $xxxxxx plus shipping (gears only about $130.00-$150 to Europe.
An entire trans I suspect will be $350-400.00 at least since everything goes by Air from here).


Thanks, Rj

Hi Richard,
I now have sympathy for what happened to you with Spruell’s CP pistons. I finally got them with the bored out sleeves only to find out when I measured the skirts that 2 of them were 0.004” oversize and the other 2 were on the money. See data I sent to Spruell below. I have to put the sleeves in a block with my torque plate and remeasure when I get them back to verify accuracy, but the static measurement is close.


I called CP myself to find out what was going on and talked to the general manager, he didn’t have an answer. Spruell insisted that I send the pistons back to him for return to CP. They went to Spruell then to CP, who has subsequently made a new set and sent them to Spruell who should have them already if not by Tuesday. (I called CP to verify their return). So my situation sounds similar to yours, which wasn’t Spruell’s fault (other than he didn’t measure the pistons when he received them and he told me that the liners were match bored to the pistons, which is obviously bu!!****.) Hopefully I`ll be able to build the new motor before the end of the year.!!!!


BTW: the OSG CR gear set is still performing beautifully. I still have oil leaking at the exit of the shift tubes on the front / top of the gear box. Any thoughts on how to stop this.???


Any new cam revelations I should know about for the new motor. With the: 31 lb. billet crank, 360 gram CP pistons and light weight Carrillo rods my plan is to run the engine up to 8500 rpm. I’m putting 46mm X 8mm lighted Ferrara intake and 38mm X 8mm lightened Ferrera exhaust valves in the head with new seats, springs, etc.


Hope all is well, see you're back on the BB so that's a good thing?

Forgot to provide raw measurement data.


bill xxxxxxxxxMeasuring Instruments:
Mitutoyo 3-4” micrometer Model #013-218 / .0001” per increment resolution, calibrated to the national bureau of standards.
Mitutoyo Dial Bore gauge Model #511-753 / .0001” per increment resolution

Raw data:
Coated CP Pistons:
#1 = 3.3491+/-.0001”
#2 = 3.3445+/-.0001”
#3 = 3.3453+/-.0001”
#4 = 3.3497+/-.0001”


Sleeve #1 = 3.3497 +.0016" (top) +.0024" (bottom) of measurement area.
Sleeve #2 = 3.3497 +.0016" (top) +.0023" (bottom) of measurement area.
Sleeve #3 = 3.3497 +.0012" (top) +.0021" (bottom) of measurement area.
Sleeve #4 = 3.3497 +.0012" (top) +.0021" (bottom) of measurement area.
 
Discussion starter · #26 ·
Cooling Transmissions & Transaxles

In a message dated 9/2/2014 11:48:23 A.M. Central Daylight Time, mirko@xxxxxxxxxxxfin.com writes:
Hi Richard,
Just wanted to ask if you have experience with external cooling of the Milano gearbox. Is it possible, and is it worthwhile? I found a diagram of the SZ cooling setup for the gearbox, and at first glance it seems to be similar to my "platinum" box. Thoughts?

Thanks!
Mirko xxxxxxxx
It is easy enough to install an outlet to an elec pump to transfer gearlube through an oil cooler and back to the fill hole or the reverse switch outlet. Or a drilled hole in the case.

However you must keep the oil cooler and pump below the level of lube required in the transaxle (or transmission ) and have the system full when setting lube level in the unit.

Rj
 
just to complement things I did not mention in the mail:
The 12.9 CB is probably a camshaft made for a dutch tuner who had a close relationship with the guys at CB who made several own design cams for him
I try to dig up the diagram, I think Catcams has one in the catalogue also, as is a 12.7 cam copied I think of a CB one also.
 
Discussion starter · #29 · (Edited)
Alfetta / GTV6 / Milano Race suspension Modifications

Rather Long...Best info at the end...

In a message dated 9/1/2014 9:58:53 P.M. Central Daylight Time,

RJ

Did fetta sedans have different ratios or final drive compared to the GT in any year?

Did you get a chance to visit Jim in Atlanta to get some transaxles?

Hope all is well.

xx

On Sep 2, 2014 9:42 AM, <AlfaR7@aol.com> wrote:

All the 4 cyl Alfettas had the same .83 5th gears. The earlier transaxles with larger toothed gears had 3.3/2.0/1.38/1.04/.83 Later boxes with teeth smaller (as the V6 used) had 3.3/1.96/1.34/1.03/.83

Yes I picked up 6 Alfetta transaxles, 3 of the 2Liter heads and one 1750 head.
Rj

In a message dated 9/2/2014 8:24:13 P.M. Central Daylight Time, writes:
Ok. Have seen other info out there. Seems like there was more variants but not in north America?

I have an alfetta box in a race car up here and it has a welded rear end. Would prefer an LSD. Still doing alfetta LSD? I don't remember if it is possible as a drop in.

Any plans yet for all the transaxles you picked up?



On Tue, Sep 2, 2014 at 9:57 PM, <AlfaR7@aol.com> wrote:

Only differences was ROW cars got a 4.3 R&P.

Yes can build them to fit in Alfetta cases. You also have to use V6 halfshafts. Really safer to run a V6 transaxle case with the modified Alfetta gears in it or a CR ratio combination of gears. Case housing, bearings and ring gear carrier components far stronger than an Alfetta.
Rj

In a message dated 9/7/2014 7:08:19 P.M. Central Daylight Time, [email]racingswim2006@gmail.com
writes:

RJ

Here's what I know about the car: The car is a 1975 GT chassis, with GTV6 trim riveted on to "update" it to a GTV6. It was raced as an Alfetta with its 2.0 (ITB?), and then as a GTV6 with a 2.5 in ITS - hence the added GTV6 trim. Denny Pillar built/raced the car on the West Coast. Denny sold the car to John Lewis in Arizona about 12-13 years ago. John used the car as a track car with the 2.5 for some time. After the second 2.5 engine failure the car was sent to Nasko in Oregon, and the 2.5 was replaced with a 3.0 (built by Nasko I think). The suspension I have not taken a caliper to yet, but from view it looks like 27mm torsion bars up front, cut Alfetta GT springs in back, and 25-26mm sway up front. Looked like rear sway was small. The engine feels very strong but I don't what the particulars are. The car exhibits nice fabrication throughout and I am hoping to learn more about the car next time I am home. I bought the car to use as a safer alternative than my street cars for on-track driving. I bought the car recently from John.

Sounds good !

Talk later
XX


On Mon, Sep 8, 2014 at 4:12 PM, <AlfaR7@aol.com> wrote:



Re the car. Both Looks nice and sounds good. From a suspension standpoint I suggest you leave the rear components just as they are. When setting up Mike Cudahy`s EP Alfetta , and as well tuning Al Mitchel`s EP GTV6 the rears ended up with about the same rate springs (125 lb inch) as the cut down Alfetta, and both were built with the small diameter Alfetta GT rear sway bar. As well about the same as my GT2 GTV6 in the rear.

As for the front the biggest improvement would be dropped spindles to raise the roll centers. With them you will probably find the 27mm Torsion Bars adequate. I was running 36mm gun drilled Euro Touring Car TBs which are NLA. Al was running 30mm TBs from Performatec.

With the 27mm swaybar the support for the swaybars should be reinforced.

Rj

In a message dated 9/11/2014 9:14:06 P.M. Central Daylight Time, racingswim2006@gmail.com writes:
Thanks, RJ.

For spindles - when I get around to front suspension I'd like to have your modified ones ready to go in so car is not immobile. Do you need cores or do you have cores already? I'd like to rim with the same 15" wheels so I'll have to grind ball joint shank, correct?


Thx as always for shared wisdom on setup. Front chassis is already reinforced for sway bar I believe. Old Shankle plates welded in plus some additional material near lower rad support as well.
RS

To answer your question I keep a set of Milano/GTV6 uprights on the shelf for modification, as well as the early 105 type that will fit the Milano/GTV6 Brembo caliper mounting holes.
Alfetta`s are a tad different.. ..

If you are running the original Alfetta 4 stud setup your spindles/uprights have the smaller outer bearing reciever area(Diameter from "memory" is about 17.3mm. The Mil/GTV6 is 19mm). Other than that, they are exactly the same as later Milano/V6.

The outer bearing area on the "V6 versions" spindles can be machined down to use the Alfetta hubs, Or the V6 Hubs (and vented Rotors ) can be used as 5 bolt, or since the wheel stud`s mounting diameter is the same (98mm) it is easy to use one of the existing holes/studs and redrill the other 3 holes so the 4 bolt wheels can continue to be used. This is a great option, as using the lighter Aluminum Brembo`s on the front with the vented rotors improves "potential" heat issues for braking. However I`ve found the stock system is more than adequate.

If you use the Alum Brembos from the Milano/GTV6 on the Stock Alfetta rotor the pads will overhang the outer diameter of the rotor. This isn`t a good situation as the pistons will end up "****ed & locked" in the bore as they are not positioned so pressure is evenly distributed.
I have seen this on customer cars at the races, and pulled the pads out and cut away the excess as a quick fix. The real solution is to slot the mounting holes in the calipers so they can be slid in about an 1/8 inch and fit the rotors correctly. This isn`t a concern as the caliper`s loads are vertical and the mounting bolts are not going to allow any movement.

"I'd like to rim with the same 15" wheels so I'll have to grind ball joint shank, correct? "

?? The ball joints in these cars are all the same. However if you are referring to the threaded area of the BJ`s stud that hangs beneath the nut that locks the BJ to the lower spindle/upright, that excess should be cut off to maximize the drop that can be done to the spindles. I need to know that distance (bottom of nut to wheel inner rim to know how much room there is to increase the lower length. I leave about 1/8 clearance to allow for wheel deflection since this is the lower (street/track/apex) area of the wheels that do flex...

However, depending on the casting molds, the reciever "socket" in the lower "A" arm for the BJ mount may have a protruding casting ridge around it. Best to remove that while the upright is off as well.

If you want to use the OE Alfetta type upright/spindle you can send a pair or call Larry at APE and he can drop ship them to me. He has all the info to do that.

In any event the "dropped" spindle roll center improvement, and steering arm mods to increase Ackerman and reduce bump steer make a dramatic improvement in handling.

Rj
 
Discussion starter · #30 ·
Differential bearings and LSD setup

In a message dated 9/12/2014 10:24:08 P.M. Central Daylight Time, XXXXXXXXXXXXXXXnshealth.ca writes:

Hi Richard
Can I ask a couple quick question

I found a used lsd rear end for my 1750 gtv

I opened it up to check it all out and found that the left side carrier bearing is badly pitted. Right side ok.

In your experience Is it likely that I could replace that bearing and outer race using the same shim and be ok or would I have preload issues.

Also I notice a little up and down and side to side movement in the splined gears the axles fit into. I am wondering if this is normal or if perhaps those serrated thrust washer/spacers they ride on are worn.
Thanks for your help
Stacy


You might get away with changing the bearings, worth a try, and if loose now use a .002 thicker shim in the left tube to start.

but:

The spline looseness isn`t between the axle and drive receiver, but due to wear in the LSD `s clutch plates.
The looseness you are referring to is pretty normal if minor, however the Clutch disk/floater plates are certainly going to need bringing back to proper clearance for the lsd to work correctly and not be noisey.
The floater plates come in many thicknesses for such setup adjustments.The overall stack should have a clearance of about .006-.008 when set up dry (no oil on the internals).
You don`t need to do anything but bead blast the clutch disk to remove cooked on oil. Best to do the same to the floaters to remove the polished surface resulting from the disk slippage.

The up and down and side to side will be reduced when the "internal slop" is corrected. However there will always be a little. This allows us to decamber the rear housing for race use.
Rj
 
Discussion starter · #31 ·
Ebgine corrosion / stud removal

From Down under:

In a message dated 9/15/2014 9:21:23 P.M. Central Daylight Time, xxxxxx@bigpond.net.au writes:
Ciao Richard,

I trust you’re well!
Please note I’ve dismantled my TS block and accessing the corrosion damage below.


What is your suggestion? Should we spot repair with Devcon Aluminum putty or look at milling the liner hole sleeves and then milling the top of the block to compensate!
Please also consider that I’m looking at installing 105 length Carrillo rods.

PS. While I have your attention do you also have a preferred method of removing the old engine block studs as I have about 4 to change!!

Thanks in advance
B.regards
XXXXX

Best to find a block that has no corrosion and good studs!. Inadequate/or no antifreeze causes this.

I take it that this is a 155 engine with the longer stroke since the comment on rod length.
If you re-machine the liner seats and cut the deck you will be adding to the piston protrusion into the block.
My suggestion is to first thoroughly clean the block using a very strong caustic cleaner (ZEP Industrial purple cleaner, or any other purple cleaner to eat out the organics on and in internal passages. It will leave the block a bit discolored. Then clean the entire thing with an aluminum brightener (acid) which will remove the aluminum corrosion (and rust from steel) This will need to be done several times to get all the corrosion out. Between all the cleanings with both cleaners use a high pressure washer to blow out/off the crud.

Before doing anything else address getting the studs out. Heat them red hot down at the point they screw into the block and let them cool. When cooled down to no more than 300 degrees try getting them out. You want the block to still be warm as Al expands more than steel and the chances of getting them out are better. Chances are they might come out then, but if you try to remove them without heating them first they will break off. (And don`t be surprised if they still do!)

Then you can ascess the issues.

If I were you and you have adequate supporting surfaces to sit the sleeves
I would simply insert the liners in place with a adequate amount of Ultra Blue Permatex sealant. This should be wiped in a area about 1 inch down the sleeve from the sealing surface up to the sealing surface leaving enough sealant in the "v" to squish out and make the seal complete. No "O" rings around the liners. As soon as they are installed sit the head and a headgasket (new, you only want pressure on the liners, you will not be crushing the fire ring) on the block and using 6 nuts on the studs tighten them by hand until snug or about 5 lbft to compress the liners into the block. Leave until the next day. Remove the head and use spacers and washers on the studs to keep the liners in place and assemble the engine.

Rj
 
RJ - we didn't get the 155 in Oz - the TS rods are ~1mm shorter than the traditional single plug items - with stock TS pistons the 105/115/116 rod bumps compression by effectivley "zero decking" the block (In stock configuration the TS pistons are down the hole about 1mm)

Removing the studs seems a little excessive?
 
Discussion starter · #33 ·
Studs

Removing the studs seems a little excessive?
Yes, he told me there were few TS in Au. Perhaps a good cleaning will indicate what damage is done to the studs,
Often, rust looks far worse than it is. Iron oxide build up is 12 times thicker than the metal it took to create it!
 
Yes, he told me there were few TS in Au. Perhaps a good cleaning will indicate what damage is done to the studs,
Often, rust looks far worse than it is. Iron oxide build up is 12 times thicker than the metal it took to create it!
They're actually reasonably common in Aus - more so than the US. I don't think i've ever seen a alfa block where the studs had corroded through, or at least corroded enough to become unserviceable/questionable - would think that if you can get the head off to start with you're probably in good shape!
 
Discussion starter · #35 ·
Corrosion / 75 TS rods

Where temps are always moderate and antifreeze isn`t kept strong enough they do rust to failure point. Seen several with studs that would turn in the head easily.

Re the comment on the 75 series Nord. It is my understanding that the internals are the same demensions as the Nord (stroke/Rod length etc) and only the 155 had the 2mm longer stroke with shorter rods .
Can`t imagine Alfa building an engine with pistons stopping before the deck height.
However I have had no interest in these motors as I don`t see any real performance increase over a well built Nord.

Don`t quote me the Alfaholics BS!
 
The combustion chamber is a better shape than the single plug, and the ports don't have such horrendous short side radii.

75 TS has same stroke as the traditional Nord, but the rods are 1mm shorter *and* built lighter - just like the block is largely similar to the earlier single plug motors, but has heavier caps and altered coolant flows.
155/164 TS uses the same rods i believe, and shorter pistons to compensate for the block height staying the same. 155/164 TS has some significant differences in it compared to the 75 TS. (Note - non-twin spark, 4 cylinder 75s had the same basic head and intake arrangement as the bosch spiders)
 
Discussion starter · #37 ·
Discussion starter · #39 ·
Large Valves????:thumbdown:

In a message dated 12/2/2014 5:41:15 A.M. Central Standard Time, dxxxxxxxmail.com writes:
Thanks Richard

Looks like I won't get to install the cams until after Christmas now, although I'll get the cam follower bores adjusted.

I will be getting the valve seats machined too.
I'm going with your suggestion of a 75° cut and standard valves and the short V6 valve guides you've sent.

Why do people bother with oversize inlet valves on a standard seat? Is there any benefit to a 1 mm oversize inlet valve? I can't see it.

Donald.

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None what so ever.
If the seat is machined and opened to it`a max opening with a 75 degree cutter,
(and the max opening on a standard seat that is 46mm OD, is 43mm at the valve contact area, which leaves a seat top thickness of .060. That is as thin as it will live and not split using a 30 degree seat. If you cut a 45 degree seat at that "opening" the additional side forces from the valve closing will expand the seat and the result is splitting or streaching and the result of either is seat loosening and dropping and that`s the end of the head.)
that leaves room on a standard intake valve of 44mm for a seat contact at the valve`s margin of .020 wide, which is a perfect width to get good seal and correct PSI to crush carbon before it can become a problem.(and maximize flow)

If you stick a 45mm valve on it, you only create an additional obstruction at the opening for the intake charge, and pick up additional weight..
As well those valves are 45 degree cut and the interior opening either has to be cut smaller or the seat will have issues. (Then the obstruction is greater still).

The only way larger valves can be used correctly is to plug and weld up the spark plug hole and either move the plug to one side or offset drill, sleeve, weld and tap for a 10mm spark plug closer to the exh side. Then cut and insert a larger seat. FYI: Seat changes and replacements have a high rate of failures .......

There`s a head build thread ongoing now on the bb. There is a link to Ferrera`s site on valves, that reinforces my point on large valves, improvements from rounding the valves outer edges.
 
Discussion starter · #40 ·
Decambering a rear differential for race use

With the Duetto`s speed issues due to higher RPM than "Prudent" (? me?)
The racecar is getting the 4.10 R&P, 4 disk LSD differential in place of the 4.56 4 disk unit. The ultra-close trans(1.99/1.59/1.25/1.0/.92) will benefit as the power is requiring speeds in gears/RPMs higher than these engines are happy with. My goal is to have a drag limited speed issue rather than a RPM limited speed issue.

The diff below was built internally two years ago, but not installed. It was originally built & modified for fitment to the Panhard link/upper adjustable link I put on the Duetto after re-acquiring it a few years ago.

To de-camber the rear I clean the top of the tube of paint & coatings, so a weldment can be run down the top of the tube just forward of the "top Centerline". This places the weld bead so that the tube is "pulled" both upward to de-camber the axle, and the forward bias of the bead pulls in a minor amount of "toe-in" which keeps the wheels more parallel during both heavy acceleration and braking, leading to more stability when braking, particularly trail braking while turning into a corner. Obviously the negative camber improves gription during side loads on the outside tire.

The weldment as seen below, and done on several other differentials bring in about .5 degree neg camber on both sides.
The boards you see are 24" long and that is the same basic length as our Race Tires are tall. The weldment drew the tube tops to a total (both sides) of 1/2 inch narrower at 24 inches. (.250 on each side) That equates to .5 degree on a 24 inch tire.

Pics should be self explanatory.
This is a common mod on LSD diffs as the internal LSD component drive parts can absorb this angularity.

I don`t think you will have much luck with this mod on welded up 101/105 open differentials.

See pics
 

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