frenchyd said:
Stampie (FS) said:
In reply to frenchyd :
Where do you get this "legitimate 400+ horsepower" number? Mguar only had 300 hp right? 33% is a big increase without aftermarket heads.
The Jaguar V12 heads are actually too big for Crisp part throttle response. If you go on the AJ6 Web site and read about the V12 they will warn you about porting the engine. You actually lose power in lower to mid RPM ranges.
Now strictly for racing there is room to enlarge the ports significantly. Jaguar has 2 different foundries cast their heads and one has slightly thicker walls than the other.
The later HE heads are not optimum for flow. Completely ported you are limited to about 400-450 horsepower no matter what you do. While the earlier 1971-1980 heads allow 750+ horsepower.
If you don't want to Rev the poop out iof the engine making it bigger will add power from idle up.
The factory increased the stroke from 2&3/4 to 3 niches and with only a 17% increase picked up 34 % more torque and horsepower. Same ports, same valves etc.
You don't have to buy an expensive 6.0 liter V12 to do that. In fact you can do much better. Using your 5.3. Use Chevy aftermarket 6 inch rods (stock are 5.7 ). Chevy Rods are 2.10. Jaguar journals are 2.30. If you offset grind the crank you'll pick up another .400 + or minus the skill of your crank grinder.
Now you'll be at about 380 cu in. But the cylinder walls of a Jaguar will really take a big bore. Some guys in Australia use Chevy 3&3/4 pistons but that gets real expensive. You need to bore the block and make custom sleeves. You can safely take the stock bore out to 3&5/8 and maybe 3 & 9/16
Since the Iron sleeve presses out of the aluminum block it's pretty easy to do. Just chuck the sleeve into a lathe and bore it to whatever size you want. Repeat 11 more times.
You can get a V12 to 7 & 1/2 liters without a lot of expense or effort 9 liters has been done.
If you put all that into a time, effort, and money into a Chevy engine you'd end up with way more than 400 hp.
I can get 400 hp out of my Chevy pretty easily. I just have to remove a couple of plug wires.
In reply to Stampie (FS) :
And the same with the Jaguar. Using the early heads, a mild porting on the intake ports only. Taking a V12 to 7& 1/2 liters depending on the camshafts used you'd be up in that 600-650 range
The deal is with Jaguar you don't need to buy a new crankshaft. Special heads, studs, rocker arms, special valve springs, special pushrods, Aluminum valve covers, etc etc etc. the way you do with a Chevy.
when I built 430 cu in small blocks back in the 1990's I would have about $11,000 in parts doing so. That was after I found a good 400 cu in 4 bolt block that passed crack testing. ( Today Is skip the hunting and go right to the new aftermarket blocks. )
When I built my bored and stroked V12 I had about $5500 in it back then. That included 2 new Piper Billet cams.
I got your Big Block Chevy right here....
Bruce Mclaren liked them too...
Not sure the aluminum block ones are in the Challenge budget but they do sound good.
frenchyd said:
In reply to Stampie (FS) :
when I built 430 cu in small blocks back in the 1990's I would have about $11,000 in parts doing so. That was after I found a good 400 cu in 4 bolt block that passed crack testing. ( Today Is skip the hunting and go right to the new aftermarket blocks. )
Remember, stampie, he can build mega HP from jag with bailing wire and duct tape, but advises others not to buy a jag... implying they will not be able to overcome all their problems - like he can! A since he knows so much about HP , nobody else can get more than 200 HP out of a chebby for less than $11,000. Oh well, I guess we should sell all our tools.
In reply to Snowdoggie :
Damn you now I have to go buy a Lola T70.
In reply to Stampie (FS) :
Somebody please post a Group 44 IMSA car for me please.
Stampie (FS) said:
In reply to Snowdoggie :
Damn you now I have to go buy a Lola T70.
I can sit there and watch that video all day.
I want one too. But here is the only one I can afford. When is Javelin's next model building contest again?
https://www.ebay.ie/sch/i.html?_nkw=tamiya+lola+t70
frenchyd said:
In reply to Stampie (FS) :
Somebody please post a Group 44 IMSA car for me please.
I think I already did. Buried back in this thread somewhere.
But I actually like the E-Type even more.
In reply to Snowdoggie :
Perhaps I should have made myself clearer.
Lee Dykstra designed the. XJR -5. 
Snowdoggie said:
But I actually like the E-Type even more.
Thank you I really appreciate watching that. I don't have any video's of me racing my XKE
frenchyd said:
In reply to Stampie (FS) :
And the same with the Jaguar. Using the early heads, a mild porting on the intake ports only. Taking a V12 to 7& 1/2 liters depending on the camshafts used you'd be up in that 600-650 range
The deal is with Jaguar you don't need to buy a new crankshaft. Special heads, studs, rocker arms, special valve springs, special pushrods, Aluminum valve covers, etc etc etc. the way you do with a Chevy.
when I built 430 cu in small blocks back in the 1990's I would have about $11,000 in parts doing so. That was after I found a good 400 cu in 4 bolt block that passed crack testing. ( Today Is skip the hunting and go right to the new aftermarket blocks. )
When I built my bored and stroked V12 I had about $5500 in it back then. That included 2 new Piper Billet cams.
okay without all the fluff.
Whats all needed to make 600-650hp?
And how much you saying this cost?
In reply to yupididit :
I last built a serious bored and stroked V12 about 30 years ago. But you can do the math. First you'll need someone who can offset grind a crank. There are more than a dozen crank grinders around here but only one I trust back then he charged me $130 when most crank grinding was $40-45 plus $35 to reharden the rod journals
You will also need 12 ( a set & 1/2) aftermarket Chevy 6.0 connecting rods and rod bearings. Check Jegs and Summit for current prices
You'll also have to regrind a pair of camshafts Nothing exotic about that. Nearly every cam grinder has the right lobes in his master set. It's just like regrinding a straight 6 Chevy two times. I've got a local guy who last time he ground some for me charged me $85 ea. Crower, Isky, all have good options, none as good as Piper out of England but that's shipping there and back British labor and shop rates. They used to have new billet cams but not anymore.
Finally you will need 12 pistons. I used Aries and I think then they were a little under $50 each. Look at China and see what they offer. It's just a forged piston. Right now if you could afford them I think I'd use the Cosworth . They are much lighter And have a better combustion pocket in them. But coming out of England they'd be spendy.
Don't use the HE heads. They were designed to meet California emissions laws not make power. Use the early flatheads. Jaguar made about 50,000 of that version and more than 1/2 came here to America. They are around. I still own 3 sets. Last time I saw a early V12 it had burnt to the ground and you could have bought it for scrap metal prices. fire ruins paint bodywork upholstery wiring etc but doesn't hurt the motor.
Use a ball mill the same size as the gasket to port the intake. Don't open it up. Just straighten it out. The stock valve is 41 mm 1.630 Jaguar has an optional valve of 43.5mm 1.715 replace all the seats if you use it. But don't do any of this if it's not an all out racer. Leave the exhaust alone. It flows too much.
OK, do you have a vertical mill? The rods and bearings need to be narrowed a bit. Plus depending on what profile you use ( for all out racing only) in the camshafts you might need to buy 1&1/2 inch lifters ( current price from Rob Beere is £18,70 each. ) and bore the lifter carrier bigger. That's easy. I did mine on a cheap Chinese made drill press and an aluminum jig I whipped up Finally either a lathe or vertical mill to bore the cylinder sleeves oversized
Oh, I missed a gasket set I prefer cometic out of England but whatever Rock auto carries is probably OK
Here's my Aries spare piston. Bit of advice, don't get greedy, I swallowed a stock seat at over 7500 Rpm on the dyno.
yupididit said:
frenchyd said:
In reply to Stampie (FS) :
And the same with the Jaguar. Using the early heads, a mild porting on the intake ports only. Taking a V12 to 7& 1/2 liters depending on the camshafts used you'd be up in that 600-650 range
The deal is with Jaguar you don't need to buy a new crankshaft. Special heads, studs, rocker arms, special valve springs, special pushrods, Aluminum valve covers, etc etc etc. the way you do with a Chevy.
when I built 430 cu in small blocks back in the 1990's I would have about $11,000 in parts doing so. That was after I found a good 400 cu in 4 bolt block that passed crack testing. ( Today Is skip the hunting and go right to the new aftermarket blocks. )
When I built my bored and stroked V12 I had about $5500 in it back then. That included 2 new Piper Billet cams.
okay without all the fluff.
Whats all needed to make 600-650hp?
And how much you saying this cost?
TLDR version of Frenchy ... Do you have a machine shop in your garage? No problem just a few thousand dollars and hundreds of your hours.
In reply to Stampie (FS) :
Mild porting does not require a machine shop. Even I have done it with only hand held power tools.
And I'm just a friggen carpenter.
I really wish you guys could settle this. I think Frenchy has some legit points, and I'd really like to see an honest comparison.
SVreX (Forum Supporter) said:
In reply to Stampie (FS) :
Mild porting does not require a machine shop. Even I have done it with only hand held power tools.
And I'm just a friggen carpenter.
You must have missed the part where Frenchy asked if he had a mill and lathe.
yupididit said:
frenchyd said:
In reply to Stampie (FS) :
And the same with the Jaguar. Using the early heads, a mild porting on the intake ports only. Taking a V12 to 7& 1/2 liters depending on the camshafts used you'd be up in that 600-650 range
The deal is with Jaguar you don't need to buy a new crankshaft. Special heads, studs, rocker arms, special valve springs, special pushrods, Aluminum valve covers, etc etc etc. the way you do with a Chevy.
when I built 430 cu in small blocks back in the 1990's I would have about $11,000 in parts doing so. That was after I found a good 400 cu in 4 bolt block that passed crack testing. ( Today Is skip the hunting and go right to the new aftermarket blocks. )
When I built my bored and stroked V12 I had about $5500 in it back then. That included 2 new Piper Billet cams.
okay without all the fluff.
Whats all needed to make 600-650hp?
And how much you saying this cost?
I won't be long winded. $7300 and just need to hit the order link.
https://blueprintengines.com/products/496-ci-stroker-crate-engine-big-block-gm-longblock-bp4962ct
