[GTOWAGON]

are you concerned with backpressure in the exhaust going to the turbo? i see your elbows are 1 3/4"I ran into backpressure problems when I had 2" collectors after I changed to 2.5" my problem went away

[TheSilverBuick]

I have a turbo that's a bit big for the application so I'm sacrificing some flow to keep the exhaust speed up and have it spool in a reasonable time. Many LS engine folks are using single 2" to the turbo, so I think a pair of 1.75" should be about right (3.14sqin vs 3.53sqin).

What I'm actually waffling on now is the primary tube size, they are 1.5" and already tough to shape out to the head port, so I'm thinking of going to 1.75" on the primary tubes too. PipeMax indicates that the header primary tubes should be 1.6"-1.8" OD, but does recommend 2.5" as the minimum collector size for the N/A application.

5500rpm.
--- Single Primary Pipe Specs --- ( Low to Mid-Range RPM Torque and HP )
Diameter= 1.612 to 1.737 Total Length= 25.3 to 27.9 inches long

--- Single Primary Pipe Specs --- ( Mid-Range TQ to Higher RPM Horsepower )
Diameter= 1.674 to 1.799 Total Length= 25.3 to 27.9 inches long

--- Conventional Straight Tube Collector Specs ---
( TQ ) Diameter= 2.499 to 2.749 Best Length= 17.5 and also 35.0 inches
( HP ) Diameter= 2.749 to 3.249 Best Length= 17.5 and also 8.8 inches


And if I find I don't have any spooling issues and excessive backpressure issues, I have a set of primatech headers I could bolt on.

[TheSilverBuick]

Got registered for Drag Week, now the pressure is really on!

[TheSilverBuick]

Despite the car being snow covered in the morning, I decided to play with some of the cold side plumbing yesterday. I think I have where the intercooler can sit. The right side will need a 3.5" hole cut in the core support, but a 90º fitting off the intercooler shouldn't intersect anything else and will be a matter of getting the plumbing to where the throttlebody lands. Expecting to get the head and intake on Friday! Yay!

The cold side going under the core support.


The airfilter is just a place holder keeping debris out of the inlet until I know what I'm actually doing for the intake.


Going from ~22gpm to 55gpm, and from a 3 row brass to 2-row aluminum should significantly improve the cooling system. Though the only real cooling issue I ever had was hitting the pump flow limit at highway speeds above 90ºF, and simply slowing down cooled the engine off every time.



As a side note, I'm contemplating building a low budget 230 or high compression 250. A set of cast pistons are $100 at summit, I have a set of checked out good rods. Just get the bores and deck cleaned up, and the crank cleaned up if it needs it. Kind of practice for getting the good engine together since it's been awhile? And have a back up engine ready to go if necessary. I don't know, maybe, maybe not. Ive got a 230 engine with a '68 1bbl head on it that looks like it had been rebuilt not to long before. I'm going to open it up and take a peak inside. I also have a '66 1bbl head I did some minor "practice" port work to, that I might be able to salvage. But I'm really curious to see what the inside of this engine and head look like. (I miss my shop!)

[TheSilverBuick]

Intake and head showed up today! I was surprised to find the intake weighs a bit more than my sheet metal one, but I don't have to worry about it leaking or cracking!

Three tubes on my "backup" Prima-Tech headers unfortunately hit the intake. Wouldn't take much to clearance them but I'm going to keep them on the shelf for now. I've decided to start on a new set of headers though using 1.75" primary tubes instead of the 1.5" of my currently half finished set. I have a box full of 1.75" U-bend pipe.

[Formulabruce]

wow! will the bigger headers reduce the Torque of that engine? I always was taught some built in restriction helped Torque . But then again, you have the Bends going on!! Good luck !

[TheSilverBuick]

It's really just trading bottom end torque for higher rpm horsepower. PipeMax says I should be using 1.75 to 2" primary tubes for 5,500rpm, and measuring the exhaust ports on the head they have essentially the same area as a 1.75" tube, so it'll be a better match. If I do not have too much turbo lag torque shouldn't be a problem! If I end up spinning more rpm, the slightly undersized header will be good for spooling the turbo. I'll be running 3.89 gears, a 25.5" tall tire and the mean 1st gear ratio of a 4L60e should get me off the line pretty well with even a little bit of boost.

If I have to change turbo size due lag, I will, but I'm hoping I don't have too.

I think the 1.5" headers I'm 75% through making will be really good for a fat torque curve from 2,000-5,000rpm on a fairly stock engine. I really just have to finish the head flange where I just have it tacked into place and they'd be good to go. I might finish them up and bolt them onto the N/A engine just to see. Considering I've never built a set of headers before (like the intake, it's my first go) I'm interested to see how they do.

[TheSilverBuick]

I got the lower mounts for the intercooler and radiator welded on, just need some strap metal for the top. I was pretty happy to see how little I needed to trim off the hood latch support to clear the intercooler.





I also yanked the head off a 230 with 250 head and it appears to still have some hone marks and no rust in the bores. It's a bit carboned up, though too, so I wonder if the rings didn't seat or if maybe the PCV valve was stuck? Don't know, but I think this could be a good back up engine. It's .030" over bored.

[Formulabruce]

Holy Intercooler! wow !

[TheSilverBuick]

I'm hoping to not have any temperature issues! 31"x12"x3" of cooler, should be plenty for this application. I figure if I'm going to try and run up to 20psi and 600HP worth of air start with a decent size.

[TheSilverBuick]

Everyone likes a good mock up. The real trouble with EFI'ing the OHC engine is that #1 cylinder fuel injector wants to occupy the same space as the thermostat housing. I have that issue with both intakes I made and this one is no different. The only alternative is to really lay the injector over and there isn't enough material in this intake to do that. I really wanted to figure out where the throttle body would land so I can continue planning the air routing after the intercooler. Lands about 4" off the radiator, so I'll need a 90º off the throttle body, but that isn't much different than my custom intake, just a bit closer to the engine.







Very similar to this, just a few inches closer to the engine and clear of the radiator hose.


Also pulled the head off the engine that looks rebuilt. It's a bit carboned up but the bores appear to still show hone marks and none of them have rust where the rings sweep by. The oil makes me wonder what the source of the carbon is. If the rings didn't seat, stuck PCV valve or just poor combustion due to fuel/spark issues? It is a 250 head on a 230 short block so the compression ratio is like 7.8:1, so could easliy be poor combustion causing it. I wonder if my '66 230 head is salvagable or if my test/practice porting has rendered it unusable?


L2258 pistons. Same ones Egge sells.

[TheSilverBuick]

Unfortunately not as much progress in the last month as I'd hoped to have. A combination of bad weather on the weekends and other priorities coming up.* I did bend some aluminum strap metal for the upper intercooler support. I need to get some matching bolts to the core support, but otherwise it is finished. I also hole-sawed the core support and ran the cold side plumbing through it. I need one more 90º coupler and then to trim down one of the pipes to get it in the right spot for the new intake.* *Boy does it tempt me to get a carb hat on it and hook up the turbo to this engine, lol!

I need to figure out where to fit the Mezier water pump and then I can go back to at least driving the car.* It's a monster of a unit compared to the small Craigs-Davies unit I had been using, and the hot side plumbing to the turbo plus 4" exhaust are now occupying the space the water pump once did.* I think I'm really going to be putting the "remote" into remote water pump.**

I need to get some new header flanges cut to start on the bigger header tubes, that actually clear the new intake manifold, but this can be done outside the car.**

[TheSilverBuick]

Haven't got anything really done here because I keep visiting the problem of where to put the water pump. I've come to the conclusion I will have to move the battery to the trunk and put the water pump where the battery was. I rather not, but I cannot come up with an alternative and the clock is ticking for Drag Week and I'm about a month behind schedule now and May is looking pretty busy for me. I need to get the short block and transmission out the door!

[6 Grrrs]

Originally Posted by TheSilverBuick

Haven't got anything really done here because I keep visiting the problem of where to put the water pump. I've come to the conclusion I will have to move the battery to the trunk and put the water pump where the battery was. I rather not, but I cannot come up with an alternative and the clock is ticking for Drag Week and I'm about a month behind schedule now and May is looking pretty busy for me. I need to get the short block and transmission out the door!

How about remote mount electric water pump?

I am doing a bunch of work on a '68 dart build for a friend and he has an electric water pump mounted to the core support and plumbed into the front of the block with AN fittings. I could certainly find out where he got it. It is a pretty serious piece.

[TheSilverBuick]

It is a remote mount pump, it's finding an adequate remote location for it and managing all the plumbing with it.

[TheSilverBuick]

Got a lot done this weekend, gives me hope on having a drag week ready car before the end of August.*

So I bit the bullet and installed the battery in the trunk. Full box, cables out the back and down through the floor of the trunk. I still need to install a power disconnect switch and heavy duty fuse, but the 1 gauge positive cable is ran to the front with brackets holding it in place. The kit came with a short 24" ground cable, so I picked up some 4 gauge ground cable until I get 1 gauge down the road.*

I figured since I have moved the fuel supply to the driver's side, I could remove the stock fuel lines on the passenger side and run the power cables more or less along the path the fuel lines used to go.


I've got three bolts holding it to the floor.**


This should clear all the exhaust pipes going to and from the turbo.*


With the battery tray free'd up, I welded a bracket to the tray to hold the water pump. I looked at options of just making a bracket to the frame or core support, but it was definitely simpler to attach it to the tray. I will probably use that space for power distribution, move the fuse panel from the fender well to the tray.


Sits about 2" higher than the stock pump did, but I do not expect any issues as long as I'm not low on coolant.*


I also started on the flanges for the new set of headers.* The flanges I have were just a bit on the small side, and the end ones needed to be squared up.* So I took a grinder to them and started opening them up.



I'm hoping this week to get a machine shop lined up for the short block and either during the week or over next weekend get a transmission boxed up to ship to a builder that has done a few other Drag Week'er transmissions, so my hope is high the 4L60e will survive behind my little L6.**

[TheSilverBuick]

Hopefully headed to the machine shop tomorrow!

[TheSilverBuick]

The progress continues. I did get the block and stuff dropped off at the machine shop. I ended up bringing them a spare cylinder head the following day because I need about 0.10" worth of valve reliefs cut into the pistons to maintain the non-interference design and they needed a head to get the proper angle with the valve size. I finished running the ground cable to the front, but I think I'm going to re-do it at a later date. I will see if I have any starter cranking issues first. I ordered a 250 amp fuse and holder to set up on the power side incase the main wire shorts out some how.

Made a simple upper radiator bracket. If I need something more substantial I'll change it, but I think it will do just fine as the upper radiator hose holds it in place pretty well. I also trimmed about 2" off the fan shroud to use my electric fan set up. The 2nd generation F-body radiator is narrower than the 1st gen.


I pulled the turbo off so I can start on the header work. I also started on the water plumbing. Because the radiator has a heater hose port I do not have to do any funny plumbing for the heater core. I'm going to get some heater hose from the parts store today and finish plumbing in the water pump. I need to wire in the PWM controller so I can control the water pump speed, then I should be pretty much ready to put the car back on the road.


The old 3-core was in pretty rough shape. Kind of hand an overheating hiccup a long time ago that bulged out the cores.

[TheSilverBuick]

A stack of parts showed up this week. I picked up a set of 3" exhaust tail pipes. I want to run the exhaust all the way out to the rear. I'm not sure yet if I want to neck down to 3.5" on the down pipe then 3" just before the rear axle or go down the 3" at the bottom of the 4" down pipe and out the back. Folks say at my power goals I'm likely fine at 3" after the down pipe, but I'm weary.



I mocked up on the left side, but I will be using the right side as I have all the fuel system running out the left, plus the turbo is on the right.


I got a custom harmonic balancer put together. An engineer I know did the fabrication of a 1bbl outer ring and a bolt on weight for his car to match the OE 4bbl balancer that is near impossible to find (can't even find a picture of one on Google!). But he never got it put on a center hub. I had Dampener Dudes in northern California put it together for me. I need to find the allen bolts and bolt it into place. I may have issue now with my crank trigger wheel. I need to check the diameter and may have to do something different. Worse case I used my 1bbl balancer for the duration of Drag Week. Dampener Dudes did a fantastic job. Lined up the timing marks perfectly.



I also got an LED display to put in the hood tach housing. I tested the LED display in my Skylark. It was reading about 4x more rpm than it was running, so I think I need to make a reference/pullup circuit for it to make it read right. I'm slightly concerned it may refresh too slowly to be of any real use, but I'll reserve judgment until I get the reference circuit complete. It was only $10, so not big loss if it doesn't work perfectly. I'm thinking of wiring it into a 3-position toggle switch and be able to switch it to display MPH as well. I'm also going to put some indicator lights in the housing, like a shift light, check engine, etc.


I also got in a 250amp fuse and case I need to wire in at the back of the car, as well as larger ground cable, so I need to re-run the ground cable. The engine bay looks so empty without the turbo!

[Jeff Hamlin]

That HB looks well done.
What year was used, and whats was the need for the larger outer ring?
Just curious.
Cheers