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351c 4v "upgrade"
#1
runninpony 
Hi!

(Pardon my Swenglish)
Im thinking of freching up my 351c 4V engine this vinter. Partly so i know that the bottom is tight and solid and partly to maybe get some extra HPs Wink .
I would like to take the car to the track a couple of times per year but mostly just driving in the street on a daily basis.
I have read about strokers on this forum and getting really intrested in trying that Big Grin .
Im planning to go with my 4V opencamber heads (may consider some minor adjustments/porting but not much). Thinking of a 393 stroker. Compression to about 9.5:1 to 10:1 (?). A hydraulic cam who is fit for regular street use. I have a Edelbrock performer dual plane with a edelbrock 1407 (750). Hedman headers and a HEI distributor. The gear is 3.70ish and i have the stock C6. Dont know the stall on the turbine but i can hold it (brakeing) to about 2 000 rpm.

Is this a ok setup?
What kind of HPs can I expect?
Any other ideas?

Im pretty new at this so..... Huh
  Reply
#2
Sounds like a good set up for the 4V. Do you know if the block has ever been bored? Personally I'm not a fan of stroker kits in our engines (Roy, Tnfastbk can speak better on that )but it's yours. Are you thinking flat tappet or roller cam? I personally have always built an engine around the cam specifications to maximize the potential in the RPM range you want. With your heads and carb/intake set up you have great potential! Good luck.

[Image: 2rr7aiv.png]

Just cruising along minding our own business when BAM!!! The LAWS show up.
  Reply
#3
ALLIANderS;83307 Wrote:Hi!

(Pardon my Swenglish)
Im thinking of freching up my 351c 4V engine this vinter. Partly so i know that the bottom is tight and solid and partly to maybe get some extra HPs Wink .
I would like to take the car to the track a couple of times per year but mostly just driving in the street on a daily basis.
I have read about strokers on this forum and getting really intrested in trying that Big Grin .
Im planning to go with my 4V opencamber heads (may consider some minor adjustments/porting but not much). Thinking of a 393 stroker. Compression to about 9.5:1 to 10:1 (?). A hydraulic cam who is fit for regular street use. I have a Edelbrock performer dual plane with a edelbrock 1407 (750). Hedman headers and a HEI distributor. The gear is 3.70ish and i have the stock C6. Dont know the stall on the turbine but i can hold it (brakeing) to about 2 000 rpm.

Is this a ok setup?
What kind of HPs can I expect?
Any other ideas?

Im pretty new at this so..... Huh

I wouldnt bother porting them heads...They will flow more HP than the block can handle...Im building the same set up right now...Im using open chamberd 4v heads..Hooker headers...Edelbrock dual plane with a holley 750cfm..10;1 compression....Im putting in a 5.30 lift cam with a 280 duration....Im expecting with just my cam change 425 too 450 horse power...my motor with a 600 lift cam and stock bottom end ...will run 550 horse too 600.....Now if you realy need more than that you can go there...lol...But just tell us what kinda horse power you are looking for..and we can all gadge what you need...But you got a good start with your choice of heads and motor..Just post what you need...And ill pop it in my desk top dyno and give you a idea of the power it could make with what set up.
  Reply
#4
marks73;83310 Wrote:Sounds like a good set up for the 4V. Do you know if the block has ever been bored? Personally I'm not a fan of stroker kits in our engines (Roy, Tnfastbk can speak better on that )but it's yours. Are you thinking flat tappet or roller cam? I personally have always built an engine around the cam specifications to maximize the potential in the RPM range you want. With your heads and carb/intake set up you have great potential! Good luck.

Thanks for your answer!
I ment to write hydraulic roller cam "full roller" lifter and rockerarms (or what its called Smile )

hyena429;83313 Wrote:I wouldnt bother porting them heads...They will flow more HP than the block can handle...Im building the same set up right now...Im using open chamberd 4v heads..Hooker headers...Edelbrock dual plane with a holley 750cfm..10;1 compression....Im putting in a 5.30 lift cam with a 280 duration....Im expecting with just my cam change 425 too 450 horse power...my motor with a 600 lift cam and stock bottom end ...will run 550 horse too 600.....Now if you realy need more than that you can go there...lol...But just tell us what kinda horse power you are looking for..and we can all gadge what you need...But you got a good start with your choice of heads and motor..Just post what you need...And ill pop it in my desk top dyno and give you a idea of the power it could make with what set up.

Thanks!
Desk top dyno sounds excellent Smile . A hp figure about 500 sounds really like a great upgrade from my 267 hp (maybe 300 with the added stuff) Big Grin

Rpm wise I dont really know, but now the engine feels best between 3 000 - 5 500 is rpm. Can i aim for 6 000 rpm even if i have a stroked crank? I think ill go for forged crank and pistons (?)
The increased cubic inch may get me a bit better go on the lower end?
Think I will have lots of questions to you guys Smile
  Reply
#5
Some one told me that Edelbrock carbs doesnt run well with Cleveland? Nothing I took much notice of but thinking of tuning the carb after stroking and more make me wonder if i shouldnt go with some "self tuning" EFI / XFI system? I dont think it will improve the top end but maybe add some in the lower end and maybe some better driveability?

Does some one of you clevelandlovers have any experience with EFI / XFI injection?
  Reply
#6
ALLIANderS;83315 Wrote:[quote=marks73;83310]

Thanks!
Desk top dyno sounds excellent Smile . A hp figure about 500 sounds really like a great upgrade from my 267 hp (maybe 300 with the added stuff) Big Grin

Rpm wise I dont really know, but now the engine feels best between 3 000 - 5 500 is rpm. Can i aim for 6 000 rpm even if i have a stroked crank? I think ill go for forged crank and pistons (?)
The increased cubic inch may get me a bit better go on the lower end?
Think I will have lots of questions to you guys Smile

That motor should be good up too 6,100 rpm from the factory i think....You got the c6 trans?....but to get 500 horse...ya... you mite have to stroke and poke it....i see a 580 lift in your future...lol..Acording too the dyno numbers "and its a old program so its not perfict"..Some guys will chime in soon im sure...Cause reason i stayed under 5.40 lift cause thats about the limit before you need real beefing up ...You need break boosters so your car will stop cause you lose so much vacuum your breaks won't work.....And you will need a big 850ish cfm carb...Single plain manifold...But if money no issue on your build and you want a monster...These guys on here will help you out..And tell you what you need to do...Few of them built strokers and know all about getting some serious real horse power.
  Reply
#7
ALLIANderS;83362 Wrote:Some one told me that Edelbrock carbs doesnt run well with Cleveland? Nothing I took much notice of but thinking of tuning the carb after stroking and more make me wonder if i shouldnt go with some "self tuning" EFI / XFI system? I dont think it will improve the top end but maybe add some in the lower end and maybe some better driveability?

Does some one of you clevelandlovers have any experience with EFI / XFI injection?
Edelbrock carb runs fine on my Cleveland. I really don't see why any brand of carb wouldn't run good on a Cleveland, if it was set up correctly. My Edelbrock ran good right out of the box and only required minor tweeking for the last 4 years. It runs almost as good as EFI, so have no longer seen the need for EFI.
Just like some people like Dodge, Chevy or Ford, some like Edelbrock, Holley or Demon carbs and they will say their favorite brand is best.

1971 Mach1
351C-4v
C6 is history-->>now TKO-500
  Reply
#8
ALLIANderS;83307 Wrote:I would like to take the car to the track a couple of times per year but mostly just driving in the street on a daily basis.

Any other ideas?

Im pretty new at this so..... Huh

Based on what you stated and with fuel prices in Europe where they are, are you sure you need that much power? There are 2 ways to make that power (a very healthy naturally aspirated or forced induction). You will not acheive your desire for a daily street combination if you choose to go with, what would be in my opinion, a very healthy 351c build. Going with a stroker will add to the bottom end torque and better utilize the 4v heads. As for porting there is no need to alter the port shape and size (especially the size) for a stroker. Cleaning up the transition from the valve seat to the valve bowl, smoothing out the short side radius and streamlining the valve guide would be about all you need. Staying on the conservative side with compression (9.0 - 9.5:1) and a cam designed to build low RPM torque will produce a powerplant that will be drivable and give you the "seat of the pants" power you are looking for while still being able to have enough vacuum for power brakes and the fun factor it sounds like you want.

That is the best advice I have for you. I have seen too many folks over the years over build street engines and then not enjoy the car like they wanted to.

Jeff T.

Low buck, touring style, '73 Convertible "rolling restoration", 351c, 2v heads with a shave and a haircut, Performer intake, Holley 650(ish), roller rockers, screw in studs, guideplates, stainless valves, Duraspark / Motorsports MSD, T-5 conversion. 1-1/8" front, 3/4" rear swaybars KYB shocks and some home brewed subframe connectors. Future plans; JGC steering box, Cobra brakes and... paint, interior, etc.

When I die I want to die like grandpa, peacefully in my sleep... not screaming, like his passenger.

[Image: 1_12_09_14_10_15_11.png]
  Reply
#9
hyena429;83383 Wrote:
ALLIANderS;83315 Wrote:[quote=marks73;83310]

Thanks!
Desk top dyno sounds excellent Smile . A hp figure about 500 sounds really like a great upgrade from my 267 hp (maybe 300 with the added stuff) Big Grin

Rpm wise I dont really know, but now the engine feels best between 3 000 - 5 500 is rpm. Can i aim for 6 000 rpm even if i have a stroked crank? I think ill go for forged crank and pistons (?)
The increased cubic inch may get me a bit better go on the lower end?
Think I will have lots of questions to you guys Smile

That motor should be good up too 6,100 rpm from the factory i think....You got the c6 trans?....but to get 500 horse...ya... you mite have to stroke and poke it....i see a 580 lift in your future...lol..Acording too the dyno numbers "and its a old program so its not perfict"..Some guys will chime in soon im sure...Cause reason i stayed under 5.40 lift cause thats about the limit before you need real beefing up ...You need break boosters so your car will stop cause you lose so much vacuum your breaks won't work.....And you will need a big 850ish cfm carb...Single plain manifold...But if money no issue on your build and you want a monster...These guys on here will help you out..And tell you what you need to do...Few of them built strokers and know all about getting some serious real horse power.

Thanks !
My writeing of "500" would be nice was because i got carried away (and thats really nice Smile ) I would be absolutely trilled with 400+ hp so i think my goal possible (?) Having a "streetable" Mach with a twist is more than enough for me. Rolleyes

droptop73;83397 Wrote:
ALLIANderS;83307 Wrote:I would like to take the car to the track a couple of times per year but mostly just driving in the street on a daily basis.

Any other ideas?

Im pretty new at this so..... Huh

Based on what you stated and with fuel prices in Europe where they are, are you sure you need that much power? There are 2 ways to make that power (a very healthy naturally aspirated or forced induction). You will not acheive your desire for a daily street combination if you choose to go with, what would be in my opinion, a very healthy 351c build. Going with a stroker will add to the bottom end torque and better utilize the 4v heads. As for porting there is no need to alter the port shape and size (especially the size) for a stroker. Cleaning up the transition from the valve seat to the valve bowl, smoothing out the short side radius and streamlining the valve guide would be about all you need. Staying on the conservative side with compression (9.0 - 9.5:1) and a cam designed to build low RPM torque will produce a powerplant that will be drivable and give you the "seat of the pants" power you are looking for while still being able to have enough vacuum for power brakes and the fun factor it sounds like you want.

That is the best advice I have for you. I have seen too many folks over the years over build street engines and then not enjoy the car like they wanted to.

A very good advice. Thanks! I want to make the best of my 4V to my hummble needs and since im not doing racing i dont need a lot of rpms and HPs. I go for the setup that is "streetable" Blush
Cant thank you guys enough for helping me !
  Reply
#10
droptop73;83397 Wrote:
ALLIANderS;83307 Wrote:I would like to take the car to the track a couple of times per year but mostly just driving in the street on a daily basis.

Any other ideas?

Im pretty new at this so..... Huh

Based on what you stated and with fuel prices in Europe where they are, are you sure you need that much power? There are 2 ways to make that power (a very healthy naturally aspirated or forced induction). You will not acheive your desire for a daily street combination if you choose to go with, what would be in my opinion, a very healthy 351c build. Going with a stroker will add to the bottom end torque and better utilize the 4v heads. As for porting there is no need to alter the port shape and size (especially the size) for a stroker. Cleaning up the transition from the valve seat to the valve bowl, smoothing out the short side radius and streamlining the valve guide would be about all you need. Staying on the conservative side with compression (9.0 - 9.5:1) and a cam designed to build low RPM torque will produce a powerplant that will be drivable and give you the "seat of the pants" power you are looking for while still being able to have enough vacuum for power brakes and the fun factor it sounds like you want.

That is the best advice I have for you. I have seen too many folks over the years over build street engines and then not enjoy the car like they wanted to.

+1 to that!

[Image: 2rr7aiv.png]

Just cruising along minding our own business when BAM!!! The LAWS show up.
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