351C 4V special build 11:1+ comp ratio - pistons ?

Usually the 70 4v heads with flatop pistons gives good enough compression for most.

If you are intent on gaining that last bit of compression you could perhaps get pistons with a slight dome top and machine the dome down until you achieve a piston crown that is flush with the block surface as you desire.

I don't think i'd recommend that. You need to leave room for rod stretch.

Mill .010" or .020" off the heads and use flat top pistons and leave it at that.



The Edelbrock dual plane air gap manifolds are not bad but i don't think you can get them with a quadrajet flange. Most performance manifolds have square bore flanges. You may find some manifolds with "dominator" flanges and you could use a adapter plate to allow the use of the Q-jet.

Standard volume oil pump will be fine, they are in fact already a high volume pump.

If you feel your engine is going to live at 6000 to 7000 rpm get the bore bushings.

Jeremie,
Do a search for Dan Jones on this forum. He is an excellent source for all things 351 Cleveland. He also posts on the POCA forum (poca.com)

Hi, Thanks for your answers, and sorry for all this faults I made in my original post, realized it when re-reading.

@ Aus Ford, I can cut the heads, but they will still be at, lets say, 0.030 (piston to deck clr) + 0.035 head gasket thickness which ends up with 0.065" / 1.65mm of squish ? .. not exciting ? no ?

And about the rod strech, which squish would you recommend having taken it into account ? is 0.040 to thin ?

Another way would be the thinner gasket + the thinner piston to deck clearance so from what you know which are the standard "on the shelve" most thin :
- cylinder head gasket
- piston (flat top)to deck clearance
?

About the bore kit, for "non race" usage dhould I get them if I spend few time between 6 and 7000 rpm (I mean time to shift)

@ Husket thx, will reach the person you recommend.

Regards.

quote:

Originally posted by Jérémie:


@ Aus Ford, I can cut the heads, but they will still be at, lets say, 0.030 (piston to deck clr) + 0.035 head gasket thickness which ends up with 0.065" / 1.65mm of squish ? .. not exciting ? no ?

And about the rod strech, which squish would you recommend having taken it into account ? is 0.040 to thin ?



About the bore kit, for "non race" usage dhould I get them if I spend few time between 6 and 7000 rpm (I mean time to shift)

0.040" would probably be ok, i don't think i'd like to go less than that. There may be others with more experience in that area that could advise differently.

Cometic make head gaskets that are, i'm told, thinner than standard. It may be worth looking into.

As i said if it is going to live at 6000 to 7000 rpm best to get the bore bushings.

Is this car for use on the road or track ?

Road car only.

I think I'll limit the RPM if I have to go with bushings, It's not a little modification, and I would prefer asking a machinist for that.

6000 rpm on the road should be enough to get you into plenty of trouble.

6000 rpm would get my 351c 4v to 100mph in first gear, that's enough trouble for me.

I think you are splitting hairs with the piston to deck clearance, you could go to a lot of expence for little gain. Stick with common off the shelf parts and procedures. Leave the exotic stuff for the race cars.

You could always consider valve relief cuts into the tops of the pistons if you desire is a zero deck height piston measurement.

Also consider the relative minimal gain by increasing your compression ratio vs the cost spent to achieve it.

Other ways to gain horsepower without having potential valve to piston clearance issues or relying on ultra thin head gaskets for sealing.

Also take into consideration if using aluminum heads on a cast iron block the expansion rate differential when using a ultra thin head gasket...Mark

quote:

Originally posted by Aus Ford:
6000 rpm on the road should be enough to get you into plenty of trouble.

6000 rpm would get my 351c 4v to 100mph in first gear, that's enough trouble for me.

I think you are splitting hairs with the piston to deck clearance, you could go to a lot of expence for little gain. Stick with common off the shelf parts and procedures. Leave the exotic stuff for the race cars.

What drivetrain combination/gear ratios are you utilizing that allows you to achieve 100 mph in first gear.

Are you using a two speed transmission?...Mark

quote:

Originally posted by 1Rocketship:
What drivetrain combination/gear ratios are you utilizing that allows you to achieve 100 mph in first gear.

Are you using a two speed transmission?...Mark

3 speed. Ford FMX.

And a 2.75:1 ratio 9" diff

quote:

Originally posted by 1Rocketship:
You could always consider valve relief cuts into the tops of the pistons if you desire is a zero deck height piston measurement.

Also consider the relative minimal gain by increasing your compression ratio vs the cost spent to achieve it.

Other ways to gain horsepower without having potential valve to piston clearance issues or relying on ultra thin head gaskets for sealing.

Also take into consideration if using aluminum heads on a cast iron block the expansion rate differential when using a ultra thin head gasket...Mark

I did not understood you point about the valve relief, you mean that I can find zero deck pistons ? that i would have only valve reliefs cuts to avoid contacts ? If yes can you give me some zero deck pistons references / links ?

I could go with very thin cylinder head gasket but this seems very exotic (less than 1mm) , I have 4V iron heads.

Aus Ford, which troubles are you talking about ? with speed controls ? or with the engine itself ?

For the gear, I think It's ok I have a 4 speeds toploader.

Compression ratio :

I see you already know the source I'm gonna toss out for the pistons you seek, http://www.tmeyerinc.com/category-s/2013.htm

notice that the 21662 piston has a Compression Height (CH) of 1.662" vs the common lower CH of aftermarket pistons being 1.645"~ish. that's .017" of engine block deck material that you don't have to remove and the same .017" of Squish that you gain

you can also have a set of pistons custom made with the extra material on the top for you to have trimmed off to suit your block, I'm pretty sure Tim knows The Piston Man that I speak of, not sure what that bill would run?

FWIW I'm on the same page as AusFord, just use the most readily available parts to achieve as close to your goals as possible, It'll Rock! no point in spending all the effort (and Euro$) to push your build to a condition that needs special fuel and special camshaft in order to run... 10.4:1 static compression with a Fel-Pro 1013 head gasket will work gangbusters

Next point camshaft :

you're familiar with the Sticky's, if you trust George's advice he has a few cam recipes that'll Git-R-Done

Intake :

you want the Q-jet for it's 'really good for driveability and fuel economy with all the power needed' characteristics and you have the parts stash... using a single plane intake would negate much of those good characteristics. if you use an Q-jet adapter/spacer plate on a dual plane intake, it'll create a gap above the plenum divider that will raise the useful rpm of the dual plane intake. choose both the intake & adapter carefully for best results & probably do a little matching where they connect, it's easy to find a plate & an intake that just don't match & cause a leak that can't be sealed with a gasket. I'd look for a 1/2" - 3/4" adapter plate for multiple reasons, the more gap above the plenum divider the more you'll lose the dual plane intake characteristics that compliment the Q-jet and hood clearnance



Last thing lubrication :

Yup the standard oil pump is already a HV compared to other engines, the 351C HV pump is like a 2X-HV

the restrictor cam bearings are neat, they save you from tapping the passages & installing the threaded restrictors but what does restricting the cam bearings really accomplish? the basic design creates it's own restriction system, as stock the cam bearing journals are being forced down onto the bearing orifice holes by all of the valve springs, not insignificant! not cheap, not very effective but can't hurt either

quote:

Originally posted by Jérémie:


Aus Ford, which troubles are you talking about ? with speed controls ? or with the engine itself ?

For the gear, I think It's ok I have a 4 speeds toploader.

Trouble I'm thinking of is the Police .

https://www.youtube.com/watch?v=Kf5nWhOeV8k

Hi 4V & proud, thanks for your message, you gave me a 351C lesson and an english lesson (maybe not understood everything correctly)

quote:

Originally posted by 4V & Proud:
Compression ratio :

I see you already know the source I'm gonna toss out for the pistons you seek, http://www.tmeyerinc.com/category-s/2013.htm

notice that the 21662 piston has a Compression Height (CH) of 1.662" vs the common lower CH of aftermarket pistons being 1.645"~ish. that's .017" of engine block deck material that you don't have to remove and the same .017" of Squish that you gain

you can also have a set of pistons custom made with the extra material on the top for you to have trimmed off to suit your block, I'm pretty sure Tim knows The Piston Man that I speak of, not sure what that bill would run?

FWIW I'm on the same page as AusFord, just use the most readily available parts to achieve as close to your goals as possible, It'll Rock! no point in spending all the effort (and Euro$) to push your build to a condition that needs special fuel and special camshaft in order to run... 10.4:1 static compression with a Fel-Pro 1013 head gasket will work gangbusters

I've had a look to Tim Meyer pistons, they are not cheap (!!), and they are still under the deck, for sur its the right direction but I'm not sure its worth spending 300+ $ to get 0.017 squish.

On the second point, where you talk about trimmed pistons, that is exactly what I had in mind. If this kind of "raw" (to be trimmed) piston exists, that would be perfect as I can trim them for free. (this machining is easy)

on the last point, there's something that surprise me, if all pistons are 0.03" deck clearance that mean that when you add a 0.04 gasket you can't really have a tight squish ? So how builder does ? they alway remove 0.03 to the block ? that's a lot ...

If you look to what I wan't to do just by changing piston I get tight squish, and high CR, and everything is reversible.

quote:

Next point camshaft :

you're familiar with the Sticky's, if you trust George's advice he has a few cam recipes that'll Git-R-Done

Intake :

you want the Q-jet for it's 'really good for driveability and fuel economy with all the power needed' characteristics and you have the parts stash... using a single plane intake would negate much of those good characteristics. if you use an Q-jet adapter/spacer plate on a dual plane intake, it'll create a gap above the plenum divider that will raise the useful rpm of the dual plane intake. choose both the intake & adapter carefully for best results & probably do a little matching where they connect, it's easy to find a plate & an intake that just don't match & cause a leak that can't be sealed with a gasket. I'd look for a 1/2" - 3/4" adapter plate for multiple reasons, the more gap above the plenum divider the more you'll lose the dual plane intake characteristics that compliment the Q-jet and hood clearnance

Really funny this picture of 4 Q-jet that's completely crazy !

Regarding the second point, using a dual plane with adapter, do you think there's a dual plane able to run at 6000 rpm ? Maybe could modify one to put the Q on it by welding aluminium or using a spacer.

quote:

Last thing lubrication :

Yup the standard oil pump is already a HV compared to other engines, the 351C HV pump is like a 2X-HV

the restrictor cam bearings are neat, they save you from tapping the passages & installing the threaded restrictors but what does restricting the cam bearings really accomplish? the basic design creates it's own restriction system, as stock the cam bearing journals are being forced down onto the bearing orifice holes by all of the valve springs, not insignificant! not cheap, not very effective but can't hurt either

ok ... I see your point, you mean that Tim Meyer bearing brings the oil wedge at the right position, so, does not reduce the oil high pressure circuit permeability, but gives realiability to the cam bearing under stronger springs ?

In this cas the tappet bore bushing question remains entire.


I forgot one point : Ignition

There's the Ford Duraspark I that I could use instaed of my (completely) worn single breaker distributor but need coil and wire and box etc ... now I see on ebay some Davis Unified Ignition using a GM architecture for 351C engine so 1 wire. What do you think of that ?

Will it fit under the air filter ?

Jérémie

If you do not have the block decked, then you need to be aware that the decks are not level as originally machined by Ford, they are on average off by 0.006" front to back, and possibly off a little bit from side to side. Therefore the compression shall not be the same in all 8 cylinders. You would have to order custom pistons with a custom pin height, nominally 1.680" (nominal 0.005" deck clearance). However, for safety's sake, before purchasing pistons it would be prudent to measure all 8 cylinders and empirically compute the deck height of the cylinder having the shortest deck to determine more precisely what the compression ratio of that cylinder would actually be.

If the engine is set-up for 0.005 deck using custom flat top pistons, 0.040 head gaskets, pistons with one 3cc valve relief, and D0AE head castings, the nominal compression ratio would be 10.76:1.

The Cleveland likes compression, but there are two considerations:

(1) With 98 octane (European) fuel you can safely bump-up the dynamic compression to 8.2:1 or more, allowing for full ignition advance without detonation, and with a small margin for error. 10.76:1 static compression would put you near that goal assuming the camshaft closes the intake valve at 70 degrees ABDC. If the engine is zero decked and equipped with D0AE heads it would have a bit more static compression than this (10.89:1).

(2) The thin cylinder walls of the production block are not real good candidates for anything over about 10.5:1 static compression however. That would be my advice for a conservative limit. The block was designed to cope with 10:1 compression, the nominal cylinder wall thickness is only 0.160".

If you insist on running very high compression then I strongly suggest you choose a piston with full-round (endurance racing style) skirts regardless of the price. Such pistons spread their load upon the cylinder wall over a larger area. This will help prevent cylinder wall cracking.

_______________________________________

My recommendation to achieve the same goal:

Have the block shaved to level the decks, and no more. By the time both decks are leveled front to back and equalized in height side to side that generally takes about 0.012" off the decks. This shall not weaken the block. This is a common procedure in preparing an engine for racing! But the benefit is now all the cylinders shall have the same compression.

Use the Ross pistons mentioned in sticky #3. They shall be less expensive than custom ordered pistons. They have a 1.668" pin height. They are forged, they have the round skirts, they are drilled for wrist pin oiling, and they use modern thin piston rings. Properly chosen thin piston rings will make considerably more power. This is a better way to make power than trying to squeeze every bit of compression that the engine can take. Then mill the heads to hit your target compression ratio, if you feel this is needed (see the calculations below). D0AE heads have 3cc smaller chambers than the D1AE heads, so they are a better head to start with if your goal is more than 10.5:1. Every 0.006" milled from a quench chamber head reduces chamber volumes by 1cc.

________________________
Here's the static compression ratio calculation as per my recommendation:

(Vs + Vc) ÷ Vc = static compression

Assuming the engine is bored +0.030" the Vs (swept volume) is 731.8cc

The Vc (clearance volume) with D0AE heads, Ross pistons, 0.040" head gaskets and the block milled 0.012" is 75cc

(731.8 + 75) ÷ 75 = 10.76:1 This is the target for 98 octane European fuel.


The clearance volume consists of:
Combustion chamber volume (nominal), D0AE casting: 62.8cc
Head gasket 0.040" compressed thickness: 8cc
Deck clearance 0.005" (block milled 0.012" and 1.668" pin height pistons): 1cc
Ross piston dome having one 3cc valve relief: 3cc
Piston to cylinder wall clearance above the top ring: 0.2cc
_______________________

Don't use a Q-Jet carb, keep them on the shelf. Use a Holley clone, like the Demon, with center hung fuel bowls and annular booster venturis. Or use the inexpensive 750 cfm Summit Racing carb, it also has annular booster venturis, but is equipped with side hung fuel bowls.

6000 rpm is no challenge for the Blue Thunder dual plane manifold and a 750 cfm carb; in fact the engine will easily rev to 7000 rpm if everything else is in order.

The Duraspark distributor will fit under the factory air cleaner, but the large diameter distributor cap will rub the radiator outlet hose if the thermostat housing that points straight-up is utilized. Late model 351M & 400 engines used an angled thermostat housing that will clear the large diameter distributor cap.

Jérémie,

Something that i don't think has been mentioned but probably makes the most horsepower for the least money (especially with the 351c) is exhaust headers.

You may have them already but if not you absolutely must get them because all the fancy engine parts you buy won't be worth a damn if the exhaust is not right and you will never get it right with exhaust manifolds.

Thanks agains for the posts (know the time it takes to type them)

I was not aware about the block geometry. Or had no more it in mind, that a serious point for sure. Having the "trimmed" piston would have done the job but in a kind of dirty way (assuming deck, non parallel to crank).

I will ask what would be the price to shave the block, I know some guys but the deal here is to get the crank line as reference and this should make the work a bit complex. Not comfortable with that but seems definitely necessary.

1st remark : I have the D0AE heads, except one CC a miss next to the rings, align piston to deck brings me to 11 + 0,04 squish (if no mistakes in my assumptions). I've made the excel sheet for that.

About the squish, is a bigger than 0,04" squish ok ?

2nd remark : I am a bit surprised about the link between comp ratio and the cylinder wall resistance, in fact here I would see more the cylinder pressure (under combustion, that reflect the engines output in some way) or the rod ratio as being the governing factors. As they dictate the radial force of the pistons against the walls.

About the pistons / rings, I've removed the pistons, and the rings preload is just absolutely mad !! I removed then with mechanician gloves and thought I would hurt my finger, I've never seen so strong rings. I definitely agree, there's a lot of power lost here !! Turning the crank with a wrench with the 8 pistons in was some sport !

About the blue thunder intake, where can I find it ? (seems not so common)

Ok for the duraspark distributor, any experience with DUI ones ?

One more thing, about the coolant, I have a lot of rust in my block, I've contacted a big industry able to remove rust but they say that acids attacks always a bit the blocks, any ideas of how I could make my water jackets clean ?

@ Aus Ford, Little story, when I got the car (1 month ago) I had it with a 80457 holley carb and a pair of (I guess) supercompetition headers or something equivalent, big freeflowing exhaust lets say. The car worked like crap, bugging all the time. I tried to adjust the carb bowl levels and impossible to make the fuel coming up to the screw hole. Finally I removed the flat screw that blocks the wrench used to adjust the carb bowl level and the threaded tubes were so low than acting on the wrench did nothing, so I unscrewed them manually (to reconnect the wrench) and found a way to get the correct bowl levels. When I tried the car pulled like completely crazy, so crazy that I had a cylinder gasket issue directly which brought me here as I pull the engine from the car

What I did this weekend

results (stock code M camshaft I guess)

quote:

Originally posted by Jérémie:

... I will ask what would be the price to shave the block ...

Here in the US about $150 to $200 USD.

quote:

Originally posted by Jérémie:

... I have the D0AE heads, except one CC a miss next to the rings, align piston to deck brings me to 11 + 0,04 squish (if no mistakes in my assumptions) ...

One mistake in computing compression shall be using the incorrect specification for deck height. The Ford published specification everyone uses is 9.206", but that was only true for the Boss 351. Most 351C were nominal 9.215". A difference of 0.009" which is almost 2cc.

The deck height can be proven as follows:

nominal deck clearance = 0.035"
nominal pin height = 1.650"
nominal connecting rod length = 5.78"
1/2 crankshaft stroke = 1.75"
_____________________________________
Total = 9.215"

Another mistake when computing compression is forgetting to include the volume of the valve notches in the piston dome, which is almost universally 3cc. One deep 3cc notch, or two shallow notches each 1-1/2cc. The pistons with raised pin heights will have one deep notch, the pistons with pin heights close to the factory spec will have two shallow notches.

quote:

Originally posted by Jérémie:

... is a bigger than 0,04" squish ok ...

Yes. Factory clearance was 0.038" (compressed head gasket) plus 0.035" (nominal deck clearance) for a total of 0.073". No problem with detonation, pre-ignition, pinging, etc.

quote:

Originally posted by Jérémie:

... About the blue thunder intake, where can I find it ...

Dennis Quella (Pantera Peformance Center of Colorado) used to sell them, I'm not sure if he still does. Dennis Carrico of DSC Motorsports in California sells them. Barry Rabotnick of Survival Motorsports sells them, Tim Meyer of TMI sells them.

quote:

Originally posted by Jérémie:

... any ideas of how I could make my water jackets clean ...

There is a product called "Evapo-Rust". I have never used it but it is supposed to work very well, and it is much safer than the using Muriatic acid (swimming pool acid), which is an older way of doing it.

I tried to put some picture of my valve lift law but pictures seems no more visible, any idea how I could display these pictures here ?

quote:

Originally posted by Jérémie:
What I did this weekend

Has that engine been taken apart previously ?

I notice a slight dish in the crown of those pistons. I imagine it would have originally had flat top pistons.

Yes pistons seems stock ones.

You manage to see my pictures ? there's the camshaft lifts that I drew in a diagramm, you see them as well ?

Yes, is the lift in mm ?

Yes lift is in mm, does it look consistent with a stock camshaft ?

ps: don't not why I can see the pictures.

quote:

One mistake in computing compression shall be using the incorrect specification for deck height. The Ford published specification everyone uses is 9.206", but that was only true for the Boss 351. Most 351C were nominal 9.215". A difference of 0.009" which is almost 2cc.

The deck height can be proven as follows:

nominal deck clearance = 0.035"
nominal pin height = 1.650"
nominal connecting rod length = 5.78"
1/2 crankshaft stroke = 1.75"
_____________________________________
Total = 9.215"

Another mistake when computing compression is forgetting to include the volume of the valve notches in the piston dome, which is almost universally 3cc. One deep 3cc notch, or two shallow notches each 1-1/2cc. The pistons with raised pin heights will have one deep notch, the pistons with pin heights close to the factory spec will have two shallow notches.

In fact I did not went through numbers I couldn't measure afterwards, so I took only piston deck disance = 0mm so 0cc, piston valve notches, head gasket thickness, head volume.

Only one thing is missing, the volume arround the piston, next to the rings.

quote:

There is a product called "Evapo-Rust". I have never used it but it is supposed to work very well, and it is much safer than the using Muriatic acid (swimming pool acid), which is an older way of doing it.

I would have never put any acid chlorhydrique into the block, it eats metal, I will see if this evapo rust is okay, I've seen guys puting a block into it, seems a good alternative.


Ok for the blue thunder, and block shaving price. Thx

From what I can make of your diagram that does look like a standard cam for that engine.

Does the timing sprocket on the cam have plastic teeth ?

quote:

ps: don't not why I can see the pictures.

Jeremie;

You have to be logged in to this web site to see pictures or graphs. If you are a "guest", you will see text, but no pictures.

quote:

Originally posted by Aus Ford:
From what I can make of your diagram that does look like a standard cam for that engine.

Does the timing sprocket on the cam have plastic teeth ?

No, I have an inverted tooth chain but no plastic on the sprocket, why ? Is it important ?

Jeremie

The original cam sprocket that was used would have had plastic teeth.

If your sprockets are all metal it makes me think that the engine has been apart before or at least the timing chain and sprockets have been replaced at some time.

You want the all metal timing set as the plastic ones are prone to failure.

Also do your valves have "Ford" on them ?

Those valves are prone to failure also and need to be replaced.

An original silent-chain cam sprocket was aluminum, covered with nylon for shock-resistance and a little more quietness. After millions of cycles in near-boiling engine oil, the nylon flakes off, producing lots of clearance between the sprocket & chain. This may allow the chain to jump time and changes both cam and ignition timing to the retard direction, which runs hotter and with less power. Worse, the flakes of plastic can and have migrated into the oil pump, causing pump damage, seizures and/or twisting-failure of the oil pump driveshaft. The fix back when the 351C was new was to replace the silent chain and both sprockets with a dual row pin-and-roller chain. The added benefit was, many 351Cs had the cam timing retarded by Ford for smog reasons; the roller chain crank sprocket has multiple keyways, one of which will reset the cam back to proper timing.

Thanks guys.

I have an inverted tooth chain without nylon on sprockets.

Chain seems in good shape not too much slack, when taking my diagrams it had a really minor effect on the timing.

The camshaft appears to be an aftermarket replacement for the OEM camshaft (115 degree LSA) having 1972 timing specs.

If you plan to keep this camshaft I'd like to suggest advancing the timing to this 1970/1971 spec:

Intake lobe centerline = 115 degrees ATDC
Exhaust lobe centerline = 115 degrees BTDC

This is referred to as timing the cam "straight-up". This shall close the intake valve earlier (70 degrees ABDC) and increase the dynamic compression ratio.

Hi, I will take some pictures about the cam.

That's funny maybe the cam is already a mild one, that would explain why the car pulled like crazy when I tried it.

I've been proposed this one : http://www.compperformancegrou...egory_Code=F351MFTCM

what do you think about it, I will take it I think as it is new and in France. The dollar/euro rate is a disaster for us, I think I will not do as much as I wanted initially … :/

regarding pistons, ross looks good but does not come cheap, I've been advised for autotec one which look good as well but no standard 4" bore available …

Valves are stock, of course I'll change them.

got my machinist on the phone, he does not want to touch my head to convert them to boss 302 rocker style, needs to manufacture a kind of jig and he's afraid of doing a mistake. Same thing for block shaving, had another company on the phone 500 … to 1000 euros to shave the block. I'm peace off, probably lives in the wrong country.

I think the cleveland had me, I will put a cam and that's all.

Three things to keep in mind. (1) The 4V version of the 351C was a "performance" engine right off the assembly line. Like Ford's dual quad 427. (2) This is a very old engine, how to make power with it was determined long ago, it doesn't need to be re-thought. (3) The 351C 4V is a big-port, big valve engine. It is not well understood by most people (including mechanics), it is not understood by most aftermarket parts companies, and it is not understood by magazine journalists. But it is understood by those who appreciate it for what it is.

Here's my suggestion. Raise the compression to nominal 10:1, which is easy to do (inexpensive TRW pistons & D0AE heads). Don't worry about having level decks. Plan on using 95 octane European gasoline, install a low overlap camshaft (short duration, 112 or 114 LSA cam). The factory (cobra jet) cam, which you already have, will get you into the 385 horsepower (SAE gross) region. Upgrade the ignition, induction & exhaust systems. The engine will perform frighteningly fast and powerful, more than street tires can safely harness.

Forget about the Comp Cams camshaft. You can do better.

http://www.ebay.com/itm/FORD-3...525&vxp=mtr#shpCntId

http://www.ebay.com/itm/New-Ha...em4ae218f262&vxp=mtr

Ok thanks guys, that's good for my moral.

In the mean time I found KB 108 pistons that looks nice, proposed by Tim Meyer.

As you say george I'll probably won't deck/shave the block unless I find a competitive price, my father called a friend of him who does a lot of rectification work, I'll wait for his feedback.

I saw this cam : http://www.compcams.com/Compan...s.aspx?csid=860&sb=2
proposed by a member of the forum living in france, is it worse trying it, It looks nice (on the description) and has some solid lifters. The problem I have is of do I adjust valve lash with my stock pedestrial rockers ? Do I need to convert to boss 302 systeme (in general they write it when needed)

In fact (okay it's a bit superficial) 0I really would like to have an engine with a bit of overlap at idle. It makes part of the fun of this kind of cars.

Jérémie

I think I would prefer the cam you have.

That Comp Cams camshaft only has 110 degrees lobe separation angle, you have 115 degrees in your cam, get a new timing set and set the cam you have as George suggested.

If your rocker arms are in need of replacement there are roller rockers available that will bolt straight on the heads without modifying the heads.