1992 5.0 build up

[NightHawk756]

Originally Posted by Italian LX

Although, if you choose to go with a lower compression because you are going add a blower, just make sure that you don't go too low of a compression based on what size blower you plan on using. Sure, low compression will allow alot more boost safely, but it will also will limit your power level significantly when you use a small to moderate sized boost blower.

True dat! Yeah, I guess I think of terms in turbo's now. Since it's so easy to up the boost from 7-8lbs. up to 25-30lbs. relatively easy. But very true. You could be maxing out the efficiency of the blower if you go too low with the compression and have to make up for it with boost. A good 9 to 9.5-1 compression would probably be ideal I would guess. What do you think Brian?

[QWKSNKE]

no higher than 9:1 in my opinion

[NightHawk756]

Originally Posted by QWKSNKE

no higher than 9:1 in my opinion

Yeah, mine ending up being 8.9-1. But, once again, I am using a turbo.

[coupe]

Noel, I have an idea: Since you're wanting a proven package, stick with the Trick-Flow Stage1 kit...but keep the motor 302 or 306 cubic inches .
You'll love the combintaion, it will make plenty of power N/A, and will support a blower down the road. This way, you don't have to mix & match parts.

You can get an eagle stroker kit for the 302 size and like mentioned before, just specify the pistons flycut for TW heads...it will be your best and least complicated path.

If you're dead-set on a stroker...you probably will want to get the components (heads/cam/intake) separately.

The TFS kit would probably limit the potential of a 331/347, but with a blower, would make 450 easily on a 302/306.

[LeeH]

Originally Posted by Robocop

If I read correct the cams offered are......

Stage One:
Lift: .499 Intake/.510 Exhaust
Duration: .275 Intake/.279 Exhaust (Gross duration)
.221 Intake/.225 Exhaust (.50 duration)

Stage Two:
Lift: .542 Intake/ .563 Exhaust
Duration: .289 Intake/ .294 Exhaust (Gross duration)
.224 Intake/ .232 Exhaust (.50 duration)

I think I will go ahead with the flat tops cut for the TFS heads with the plan of using a mild amount of boost. I do not know what the above numbers mean however using the 2 cams above what would be the differences of both. Is one cam set up for more low end and the other more mid range?

One thing at a time.
There are more specs to those cams which are the most important, They are the timing events(valve opening and closing in crankshaft degrees). With a good cylinder head the cam wont have to be biased towards either the intake or exhaust as many OTS cams are since the OEM heads are crippled by design. You want to keep the intake clean and not bleed off excessive amounts of cylinder pressure doing it, With an efficient induction package you wont have to have large amounts of overlap or lots of duration. You will however want a fairly fast ramp in order to take a good deep breath. The higher the volumetric efficiency and the longer it stays there not only equals more power but more usable power(flatter power curve). On a 302 use nothing smaller than 1 5/8 primary tubes and on anything larger than a 331 use 1 3/4 or 1 3/4 step headers.
The specs you see in those cams are gross valve lift with a 1.6 ratio rocker arm and duration from seat to seat or .006 and duration at .050. the only thing that both the duration figures show you is how fast the ramps are. The ramps are the opening and closing ramp of the lobe above the base circle of the camshaft. Lobe lift is the amount of total lift above the base circle of the cam, The rocker arm ratio multiplies the lobe lift which in the case of both of these cams is 1.6 times the lift at the lobe its self. You can play with rocker ratios to increse the area under the curve which equals efficiency(power).

Originally Posted by Robocop

Also LeeH what does it mean when you say the intake flow stalls above a certain lift? Does the car actually stumble or fall flat losing power? I am going to Howtons Monday and need to tell him what to get prices on for me. Once I have that I will use that as a base and see where else I can try to find a stroker Kit. I also have to call Pro Line in Woodstock Ga. Those guys seemed to really know what I was looking for however I did not get to talk to them for long. I said I was shopping around and they said to call back when I knew exactly what I wanted.

Italian LX hit the nail on the head, However a little bowl and chamber work can fix some of that.

Originally Posted by Robocop

One more thing.....

Would it be the same to start with a higher compression motor and use no boost. Lets say that I went with 10.5:1 N/A would it be just as good to go lower like maybe 8.5:1 with a little boost ? Doesnt a supercharger simply increase the compression in the chamber? It seems that a N/A motor could do almost as well by simply starting out with a higher compression ratio in the first place.

The problem with higher compression ratios is pump gas, Now with aluminum heads you can run up to 11.5:1 N/A on pump gas(91+). The reason is aluminum transfers heat faster(simplified version) while cast iron retains heat better which helps promote HP, Heat retention when coupled with higher compression(above 10.5:1) will cause detonation. This is unless you pull a ton of advance out of it which will negate any and all advantage of having more compression.
Yes a blower will increase compression but it does way more than that, It provides an artificial atmosphere for the engine to operate in. Swept volume is all you have to try and encourage atmospheric pressure to enter the empty cylinder, As the piston moves down on the intake stroke the intake valve is opening. The piston moving down creates a low pressure area and as the void is increased the pressure drop is higher, Atmospheric pressure is trying to fll this void through the open intake valve. The intake valve wont start to close until after the piston reaches the bottom of its stroke and changes direction into the compression stroke. The reason for this is the column of air rushing in will continue even after the piston is moving up towards TDC, This is because the mass of the air column is wanting to continue to move. The higher the engine speeds the more of a ram effect you get and this is what causes peak volumetric efficiency and the negative effects of intake reversions, So this is why valve timing is soo critical on a N/A engine. The exiting exhaust is also effected by this as well just a tad different, I could go on and on and on but for the sake of everyones sanity and patience I wont. A blown engine doesnt have to rely on the barometric pressure to fill the cylinders, Your making your own atmosphere within the intake tract so your forcing air into the cylinders. At 2 bar you have theoretically doubled the displacement of the engien, 2 bars is double atmosphere. 28in HG is roughly 14psi soo at 28psi or roughly 56in HG your 302 would consume the equivelent amount of air as a 604ci engine at 100% VE. Soo a blown engine wont need the overlap a N/A engine would since its not trying to coax atmosphere into filling the cylinder, If you run an engine with boost and a cam with much overlap then your going to be blowing boost out of the exhaust which is wasting power. Overlap is when the exhaust valve is closing and the intake valve is opening, There are a few degrees there where both are open a small amount. This increases the amount of scavenging to help pull in fresh air through the intake valve and help flush spent exhaust gasses from the cylinder. You need to make up your mind right now which way you want to go, Its cheaper to do it once than twice. Also regardless what people say none of the alphabet cams are good for boost, Too much overlap and lazy lobes will hurt power.

Originally Posted by Robocop

Sorry so long however I have never tried to figure out the finer details of a motor. I thought I knew the basics and found out that I do not know much of anything at all.

Just remember suck, squeeze, bang, blow! I deal with mostly boosted applications on a daily basis as I R A mechanic sorta kind of . I think Dale might vouch fer me
Anyway I have left out alot but I am afraid you might get a little lost as well as my translation might loose a little of its usefullness in an extremely long and boring post.

[Robocop]

LeeH I thank you for the input and it is confusing to me however you are correct when saying I do not want to do this twice. I have to get this right the first time around as I can not afford to mix and match later on.

I really want to get the bulk of the stuff done soon as I feel this will motivate me to just finish this project. The cam stuff is confusing to me so I have been searching old threads here for others who have proven combos that work. I have read almost every old issue of the Ford mags looking for reviews and packages as well.

I will say that I really do not know what is best however if I can just get to my goal of 450 HP I will be happy. To me I would not know the difference between a custom cam and one made from an old broomstick so again I must rely on the advice of others. The main thing right now is that I would like to go ahead and order the top end kit and it comes with a cam already. When I take my block to Howtons he said he would be happy to machine it and put the short block together afterwards. If he did that I would end up with 2 cams if I go with a custom one.

I do kind of actually like Coupes idea of keeping the motor a 306 in order to best work with the TFS kit. If I were to do this and use a little boost what would the difference be in HP between the 306 VS the 331 if both motors had around 8-10 lbs of boost?

Also thanks for the graphs ItalianLX however that stuff all looks like latin to me but it was an interesting read. I need to make my decision before the next week so I can order my top end stuff. Richard and I were talking tonight and we were trying to figure out what best combo to buy. The TFS website shows 2 different kits in the street heat vs track heat kits. One makes about 350 HP and 370 Tq while the other makes 370 HP and 350 Tq. I think the main difference is the intake design and I thought it best to get the kit with more torque. Anyone have experience with both intakes and the better choice for street use??

This thread is getting long however it does help me greatly to gain every bit of information I can. I will have this car running before the Summer if at all possible....thanks for everything.

[1sicklx]

Originally Posted by Robocop

One makes about 350 HP and 370 Tq while the other makes 370 HP and 350 Tq. I think the main difference is the intake design

That is correct .. individual part numbers for the kits are identical except for the intake. However, the ratings I saw were 350|370 and 360|350, but those are only estimates anyway.

[Robocop]

Yeah I could not remember the actual numbers but did remember there was a little difference in both kits. The estimates given by TFS are nice to know however was their estimate based on a standard 302 N/A ? If so with a little boost my 450 HP goal should not be that far away

[1sicklx]

Testing was based on a 306 NA with a few other mods if I remember correctly

[coupe]

Originally Posted by Robocop

I do kind of actually like Coupes idea of keeping the motor a 306 in order to best work with the TFS kit. If I were to do this and use a little boost what would the difference be in HP between the 306 VS the 331 if both motors had around 8-10 lbs of boost?

Not a whole lot of difference with the boost. One of my friends had a 302 with heads/cam/intake with 42# injectors and an S-trim Vortech. It made 435-445 hp nicely. He sprayed a little on it for 500 hp...stock bottom end. It was in a full-weight hatch and went 11.1 @ 126mph on drag radials.

My other buddy with a single turbo makes 510-520 rwhp with his 347 and the turbo. It made 488 rwhp with the same exact setup on a 306 with stock cam! It took some more boost, but still made the power.

In a nutshell, you'll be happy with a boosted 306. And it will probably run great on stock computer with a correctly calibrated MAF and injectors