Low Budget Head Help Please - (Forced Induction)

[burgandy81]

Hi All,

As the holidays get near I have a fun time being my own Santa. It is a tradition we adopted as my family insists i am difficult to find gifts for. It works out well, I order everything and it is scooped up from the post before I get home from work and re-materializes weeks later as small gifts from various family members. Typically this is a long list of small and medium Fiat parts. It beats sweaters and ties!!!

This year I am thinking about the head.

To frame this thread a little, my Fiat is a budget driven exercise and I have limited free time to work on it. Cost saving and time saving tips are much appreciated.

Car in current state (running OK);
1980 FI
Megasquirt Fuel & Spark
LS1 coil pack (no dizzy)
Lancia intake w/ large injectors
Stock 4-2-1 exhaust
Parts include a NOS '79 head and a used '79 head complete as core/parts/donor.

Future plans;
Forced induction - probably an Eaton Supercharger

SO! With all of that out of the way.....I am looking for parts advice.

My plan is to build up the NOS head myself to swap onto the car in the near term and use the same head for eventual forced induction.

1. As a NOS head I DO NOT plan to have any machining done. Is this prudent?
2. I intend to use the factory used valves from the 79 head if they are straight. Any thoughts or concerns? Possibly stainless exhaust valves?
3. Re-use factory valve springs??? Do not plan to rev past 7000
4. New bronze guides
5. New silicone valve guide seals
5. Which head gasket???
6. Stock cams???? I know there are a vast array of Fiat/Lancia cams that will fit the head. Any suggestions?
7. Adjustable cam wheels- these may make the stock cams a good choice?

Thanks in advance for access to the Fiat Brain Trust.

Cheers,

Jordan

[djape1977]

you need sodium filled exaust valves and thicker head gasket in order to drop compression ratio

[131]

G'day Jordan,
My plans are basically the same, standard cams, stainless valves, stock head, no porting, standard springs, good guides and seals, except I'll be using a 2mm thick stainless decompression plate. Sodium filled valves would be nice, but not essential.

[Daniel]

You never talked about the psi from the blower/ boost? In general on the intake at least you'll want a stronger
valve spring as the boosted pressure will add to the resistance on the intake valve. Stock cams can work for
a build but ask yourself this do you really just want more power after doing a tricky upgrade or
do you want a lot more? With some planning you could have a beast of an engine with a blower.

You would want better Connecting Rods and Bearings only quality rod bearings for these engines are clevelte 77.
On the head I would smooth out the combustion chambers and do mild porting.
My Engine I'm using larger Studs to replace the head bolts so i can tighten the head using more psi per square inch.
High Pressure Oil Pump mandatory! I redesigned mine.
On the Cams I think I have an Ideal what would work for you but would ask someone who is better versed on Super
Charging then myself before I make a recommendation.
Make sure you make the proper mods to the oiling system like in the photo below sorry i need to take
more of the closer to complete work.







this is more of a finish product but not the same head this is a 1800 with mild reshaping





and then you need an attractive woman to assist you with your fiat build!



Any how these are some tips off the top of my head

[burgandy81]

Love this site!

DJape,

I have read about the Lancia Sodium filled valves and occasionally search Euro e-bay for them. At this time they seem out of my budget unless you happen to have some that are up for sale and reasonable cost?

Hey Mick,

Nice to see you here, I have seen your posts on T124, I am Updated FIAT over there. What pistons will you use? I am planning on using the stock US spec units that give 8.1, which i feel is very low and should work well with boost if I can keep everything cool. I have a large front mount intercooler to help with this.

Daniel,

I am looking for over 200 Hp at the wheels as an ultimate goal. First set up will target 150 using a bypass valve.

As for the engine, I am thinking I will use the stock low compression(8.1) US pistons and stock rods. I feel this will be exploring their limits but may be OK with proper fueling and cooling. Better bearings are defiantly in the works and I am looking at oil squirters to help keep the pistons cool and an A-A I/C for charge cooling. An upgraded oil pump fits this mix nicely. 12mm ARP head studs are also a consideration.

Can you help me understand your photos a little? What should be done in photo one with the blue circles? Should these be ground flat to drain the "Oil Pocket".....

Is a 3 angle cut a good idea on my NOS head?

I will look for any sharp edges within the cylinder head. This should help with hotspots! Thanks!

Please keep the ideas coming and thanks again!

Jordan

[131]

What pistons will you use? I am planning on using the stock US spec units that give 8.1, which i feel is very low and should work well with boost if I can keep everything cool.

I was building the engine originally to run N/A on LPG, the pistons have a slight dome, 1.4mm I believe, block was decked 0.8mm because of the lower compression height of the pistons. The head is from a 132 1800, which has smaller chamber volume than the 131 2 litre head, static CR was calculated at 11:1. The LPG car has gone to the scrapyard, so initially the 1800 head will go on to the new car, with twin IDF 40s, 40/70 In, 70/30ex cams, headers and a 2" exhaust. The larger chamber head, with stock cams, will go on to the new motor with the 2mm decompression plate. Until I measure the 2 litre head, I won't be able to calculate what the CR will be on the new motor.

[djape1977]

try looking for lanchia dedra turbo valves. it was still in production in mid 90's

[Daniel]

Daniel,

I am looking for over 200 Hp at the wheels as an ultimate goal. First set up will target 150 using a bypass valve.

As for the engine, I am thinking I will use the stock low compression(8.1) US pistons and stock rods. I feel this will be exploring their limits but may be OK with proper fueling and cooling. Better bearings are defiantly in the works and I am looking at oil squirters to help keep the pistons cool and an A-A I/C for charge cooling. An upgraded oil pump fits this mix nicely. 12mm ARP head studs are also a consideration.

Can you help me understand your photos a little? What should be done in photo one with the blue circles? Should these be ground flat to drain the "Oil Pocket".....

Is a 3 angle cut a good idea on my NOS head?

I will look for any sharp edges within the cylinder head. This should help with hotspots! Thanks!

Please keep the ideas coming and thanks again!

Jordan

Hey Jordan

Sorry i rarely take photos of my projects and i'm bad at phototherapy but ill post some more later to help
make more sense of this. On the Oil pockets you don't grind them down just drill a drain hole in the sides that's
what the blue arrows represent.

[fiatfactory]

.

[burgandy81]

Hi Steve,

Thanks, Your car sounds like my car if I was much more skilled, had a bigger budget and lived in a country where we had access to more Fiat goodies!!! Will you start a build thread on T124?

Bronze guides - Check
Upgrades Springs - Will investigate.
Sodium valves - Will investigate, a contact # is appreciated. What are your thoughts on Stainless valves as a second choice?

I will have to dig out the head for a casting # although i was told in was a NOS 79 2L US head. This would have made it a carb head with emissions. EDIT: HEad casting # are 132AC2C, 4439644 and FIAT S62

Your thread on T124 bout head preparation is quite good, would you suggest following the guidelines for a turbo head? Close enough for Supercharged?

Stock 4-2-1 exhaust is quite good, so i understand. I also know there is a special kind of Voodoo required for forced induction. My only planned change was to step up to 2.5" exhaust at the cross member where the factory 2 pipes join into 1. I am also hoping to use the least restrictive cat, res and muffler my budget would allow. What will you be using?

You are right, the Croma intake does not work on LHD set up. I have the Tipo/Dedra unit with long, but not straight, runners.

Interesting comment on the 10mm ARP head stud kit? Why not change to the 12mm kit? I would be happy to hear the 10mm kit will work as I can use this on my current block for trial purposes.

Your engine sounds great, and beyond my budget. I will be exploring the limits of stock NA pistons and rods for posterity:)

You did not mention oil squirters? Any thoughts on these? Which ones to use, how to install, etc? I was thinking of following in the footsteps of the Beardmore Bros.http://www.beardmorebros.co.uk/website% ... arger.html

I am also keeping an eye out for a 131 box although the are very rare around here.

Cheers,

Jordan

[fiatfactory]

.

[Daniel]

12mm ARP head studs are also a consideration.

I'm going to do this myself using 11mm instead of stock but i'll have to drill the head bolt holes out some
to get them to fit...