jonny_sanchez99

Hello I'm planning on building a 355 and was wondering what kind of power it would make based on the combo and wondering what I could improve based on suggestions thank you
engine = 350 bored .030 to a 355
2 bolt main
Hypereutectic aluminum pistions
Piston head volume = +7cc
Flat top
Heads= blueprint aluminum H8002k
1.5 rocker arms
Specs
64cc combustion chamber
Intake runner 195cc
Exuast 75cc
Intake valve= 2.020in
Exuast valve= 1.60in
3 Angle valve job
Cam = comps can Xtreme energy XE294H hydraulic flat tappet
Rmp range 2800-6500
Valve timing = .006
lobe separation= 100°
valve lift = .519 intake .524 exaust
Duration 294 Intake 306 exuast
Intake = Holley stealth ram rpm range to 6500
Ported to flow around 300cfm
transmission 700r
Gears = not sure yet
Torque converter= not sure yet
Subframe connecters
5/8 headers
3inch dual exhaust
I'm planning to use as a daily driver and was hoping around 400rwhp but still not sure what type of gears or torque converter to choose.
not sure what the compression would be at I was thinking around 10.1
Not sure if this would be the best cam for the build, looking for a mean idle
Any help or suggestions for improvement would be much appreciated

fasteddi

iTrader: (2)

I gotta say that a huge flat tapped cam!! Exspecially foe a street rod. The converter I would say would need to be a 3500 or greater stall and the gears a minimum of 3.73s to really take advantage of it dependent on your tire size diameter.

Also I would aim for at least 10:1 but more like 10.5:1 if you can. Get a good quench of .030-.050 and be prepared to rev It to a solid 6-6500rpm to hit that cams power curve.

400rwhp... I'm not sure if you'll obtain that. Mabey 450 crank hp... but rwhp... it will be a tight one. Any idea what those heads flow?

But who knows. I had a weird combo this year and it did well. A 385 sbc, dart iron 200cc heads, 11.1:1 compression, 3500 stall, 3.23 gears, a baby and I mean baby xe268 cam, 1.6 comp gold rockers, performer rpm intake, Holley 750 carb. The car ran 11.60s@114mph every time, shifting at about 5300 rpm.. Lol talk about granny shifting. It would even pull the tires and tun 1.5x 60 foots. Tq monster.

Orr89RocZ

iTrader: (20)

I dont like flat tappets but it should run good. Agree on more comp, 10.5:1 would be nice.


Might get into high 300's whp but hard to dyno well in an automatic with high stall. Need 3800-4000 to get that thing moving. 3.73 gear

If a daily may want to go down 1 size in cam. Or go hyd roller

jonny_sanchez99

I wasnt sure if this cam was too big for my plans but what cam would y'all recommend for good power for a fun daily driver with a nice idle. This is gonna be my first rebuild and looking to get it right the first time around.The heads seem to be pretty decent heads from blueprint but I don't see alot of information with theese heads or combos using these heads and using speedmaster compression calculater I'm getting 10.8.1 compression with this setup
thank you for the suggestion

Orr89RocZ

iTrader: (20)

I would do the 284h at the biggest

Tibo

iTrader: (15)

Why even consider using a flat tappet camshaft? Did you unknowingly purchase an old block? If you haven't started building the engine then the best thing you could do would be to sell the block and get a 1 piece rear main seal roller block or convert this one to a roller setup. The cam is too big for a daily driver, your brakes will suffer and you will tire of the uber poor gas mileage. If you did use that cam I don't see it breaking 350 wheel hp.

cuisinartvette

After 3 xe ft cams going flat right away Id never come near one again, x2 on that being way too big
Low compression/big cam combos usually dont "run", gear it for the cam not cruise rpm or you wont like it when you stand on it.

What was the final size of the head its real tough to get 300 cfm through a 2.02 valve

jonny_sanchez99

I haven't started building the engine yet I wanted to see what other people with more experience thought of my setup. I'm planning to purchase a 2 bolt 1 peice rear main seal.
so far I'm going to look for another cam more sutible for the street what would be my best bet ? A hydraulic roller or mechanical flat tappet ? What cam do you guys think would serve this combo well I haven't bought any parts yet I'm just seeing what works best together first
thank you

fasteddi

iTrader: (2)

My thought if this is a daily driver, like 5k miles plus a year, Hydraulic all day every day. If not then may as well go solid. I personally am doing a roller swap on a non roller block at the moment as well.

Lots of good cams that would suit you. One that sticks out to me is the comp xr288hr cam. Thats a hydo roller. That's if you are building it to rev to 6k. If you are just going to drive it 90 percent of the time then a step down on the cam size may be alot better, like a xr276hr

jonny_sanchez99

Thank you for the help and the cam selection. I had alot of trouble deciding what cam would work best for overall performance and drivability. How much power do you think it will make at the rear wheels ?
Any tips when building the engine? Like things to look out for?

Orr89RocZ

iTrader: (20)

Stick with a good hyd roller in that 230 deg range at .050 and it has potential to make 360-375 whp i would say. Thats pretty stout. Just did a 350 lt1 with hot cam and 195 trickflows. Made 355 thru a 6 spd. Bigger cam and automatic would be in that range still

Street Lethal

iTrader: (16)

You decided on the Stealth Ram so this will at least cover you on higher RPM. But you're stuck on the three areas that everyone usually is when deciding on parts for a build; stall speed, gears and camshaft. You mentioned the XE294H as the cam you wanted to go with. That's a very big camshaft, and it calls for a minimum of 1 3/4" primaries on the headers, but you're considering 1 5/8" in your list above. The cam will give you that mean idle that you want, but it will also give you very low vacuum at idle, just 8" Hg worth at 1000-RPM. You'll have a problem with braking if you're using the stock brake system, and it's not worth the trouble nor headache for sounding mean, believe me. Anyways, it's kind of easy to determine the stall speed and rear gear ratio to go with when you already know your transmission gearing in the 700R4, as well as by looking at the camshaft chart. Take a peek, and you'll see where you need to be with both. Just dial it all in by contemplating where you want your average RPM to be when cruising in 3rd...

jonny_sanchez99

After seeing everyone mention that the cam is too big I'm deciding to choose the xr288hr cam or the next step smaller cam and a hydraulic roller cam since it will be a daily driver. Thanks for the advice I don't want no problems with braking with the low vacum rather choose the right cam for my application instead of over camming the motor. I don't need a high hp monster but just something fun on the streets and can race every now and then

Tibo

iTrader: (15)

The XR288HR is still too much cam for you in your daily driver. You want an intake duration in the 210-224 region. 236 intake is just too big for you at this point. ~13-15 mpg combined will get old real quick. Do you have the depth of knowledge to correctly tune this engine to the point that it will perform well on the street? For a cam that big in a 350 you would have to retune startup, idle, spark curves, the entire fuel curve and the list goes on. And if you can't correctly tune this engine from the get go it becomes a safety concern for everyone else you share the road with. IE because the lack of vacuum to your booster would kill brake performance, the engine could start surging/bucking, the engine could die in traffic at stop lights and you lose power steering and power brakes. All those scenarios happened to me when I first started out my tuning adventures with a 355 with good heads and a bigger cam.

jonny_sanchez99

I appreciate all the help and very glad I got second opinions from people with alot more experience what cam would you recommend if the pervious ones are too large ? Would you recommend a comps cam fuel injection cam or a smaller extreme energy cam ? I appreciate the concern for the safety

fasteddi

iTrader: (2)

Yea the 288 is a bit big.. and like a said earlier if its a 90 95 percent street macine then I think the xr276hr is a great cam for your application. Any smaller (under a intake durration of say 220-222 @.050) and you are missing out on alot of hp. And I guarantee it you will up size the cam later. This cam keeps you in a good power range and tops out at arround 5 5500rpm max. On a street car that's a good area because rarely are you going to go above that anyways.

I ran this cam below all year. Hydro flat tapped so the ramp rates are slower compared to the xr276hr. And trust me it's a blast on the streets. The durration is compatible to the xr276hr. But any smaller then about 224/230 durration... you'll regret it. The proper converter...at least 2500 stall and good gears 3.73 and it'll be a good negotiation between a straight up race car, and a straight street car. I shifted at 5300rpm with the cam below and ran 11.60s@114mph constantly. Granted I have a 385 ci engine and more compression 11.1:1 but you get the idea.



You toss this cam in, 3.73 gears and a solid 2800-3k converter and it will be a wild tq monster on the street and a ton of fun. This is the xr276hr below. For a roller, I personally think it's a great cam, not too small not too big. And you will still have plenty of vaccum to run your brakes.

Orr89RocZ

iTrader: (20)

A 276hr is not huge for a 355. Its a good cam. Gm hot cam is mild in 350's but makes good power and tunes easy. Drives nice. The 276 is touch more aggressive lobed. Smaller advertised duration but bigger at .050. Better air flow curve with the more aggressive valve lift curve. It be a good cam to have and will produce good hp.

jonny_sanchez99

Thanks everyone for the help after seeing everyones suggestions I believe I'ma go with the comps cam xe276h since it's right in the middle and should be good for the street thank you everyone for the help
should be a fun daily driver by the time it's all said and done

QwkTrip

iTrader: (22)

Definitely a better choice. That 294 would have been a dog around town.

In this day and age it seems that wiping cam lobes is just a matter of time. I would invest in a roller cam. Hydraulic roller lifters are quite good these days and can support more RPM than you will make. No need to have a solid roller.