Motor Transmission Selection Advice

[Doc76]

yes, I meant lb/hp...

To make 450 hp with a 347 should be relatively easy and not too much of a budget killer. If you are going to do this in a stock block don't waste money with a forged crank and heavy rods as the block will break before the crank and/or rods. The Mahle "PowerPak" pistons come with a nice ring package and are also budget friendly. Get the compression up to 10:1 - 10.5:1 and top it off with a decent set of heads, an Edelbrock Performer RPM dual plane intake with 750 Holley and you are 95% there... call Mark Chacon at Bullet Cams and have a custom cam ground and you will have your 450 hp without breaking the bank.

That’s fantastic info
Thank you for taking the time to lay that out.

What are your thoughts on spending the money on a Dart block when doing a 347?
My understanding is the block is the weak link and the upcharge for the Dart seems minor in the grand scheme

[BUDFIVE]

X2 on 347 for 450ish hp. I used the Mahle PowerPak pistons for just over 10.5:1, AFR CNC Renegade heads, custom Bullet cam, Edelbrock Performer RPM Air Gap, and QFT 650 to hit 450 hp. I did spend the coin on an internally balanced forged crank and rods which is probably overkill as Stangracer suggested. I used the PowerPaks in 2 motors in summer 2023–only problem is the damn wire locks-my fingers still hurt

[StangRacer]

That’s fantastic info
Thank you for taking the time to lay that out.

What are your thoughts on spending the money on a Dart block when doing a 347?
My understanding is the block is the weak link and the upcharge for the Dart seems minor in the grand scheme

I really like Dart blocks. The only real difference between the Iron Eagle and SHP is the Iron Eagle has 4 bolts on all five mains where the SHP only has 4 bolts on the center three mains. There are some differences in oiling provisions that really only make the Iron Eagle advantageous when using a dry sump system. The Iron Eagle also comes set up where you can restrict the oil to the top end but this could easily be done with a SHP if needed. Once you build engines with Dart blocks you will never want to go back to stock blocks. I just finished building a short block for a fellow road racer last week that used a stock block with a girdle and HATED every minute of it. The girdle got in the way of everything. I must have had it on and off at least 20 times while measuring the main bearing clearances. He didn't appreciate it when I told him the only thing the girdle does is holds the block together when it splits...

The FRPP Boss blocks are nice too. The knock on them is they have shorter cylinders so the pistons come out of cylinders more at the bottom of the stroke and can cause the piston to lose stability. This is not an issue if you have a piston designed with the correct break point. If you find a good deal on a FRPP Boss block I would not shy away from it due to the shorter cylinders...

The World Products blocks are nice too. I have never used one, so I can't comment with personal experience, but they look good on paper.

If you are going to step up to one of these blocks, then I would suggest going with a forged internally balanced crankshaft. When spending this kind of money stick with either an ATI balancer or one from Innovators West. I would still stay away from the heavy rods and look for a reasonable lightweight I-beam rod. Again, the Mahle "PowerPak" pistons would be a good choice. They have a 1mm/1mm/2mm ring pack and are made of 4032. 4032 is a better material for a street engine as it allows you to run tighter piston to wall clearance and will maintain ring seal for a longer period of time. However, 4032 is more susceptible to be damaged if you get into detonation.

Any 190 cc volume runner cylinder head should be able to easily achieve your horsepower goal with a custom ground cam and 10:1 - 10.5:1 compression. I really like the TFS Twisted Wedge heads. They are advertised as a 170 cc runner but the intake valve is closer to the intake side of the head, so the runner is shorter. It has the cross section of a normal 20-degree 185-190 cc head. The thing I really like about the TFS Twisted Wedge is it has a very efficient chamber, so you don't have to run a bunch of timing. Usually, 30 degrees total will make the most power. In addition, the TFS head has flatter valve angles which helps with piston to valve clearance. Keep the quench tight, around .040 or even .035 if you don't rev it over 6500 rpm, and you may be able to get away with 11:1 on 93 pump gas if you keep the AFR around 12.8 - 13.0.

[Fman]

What do you think you’re into your power plant/tranny for $ wise?

I built my car back in 2021, I believe the transmission, engine w/power steering was around $22k with the PF4 EFI induction. Not sure what that equates to in today's dollars. My engine was built by a local engine builder close to where I live.

[Doc76]

I built my car back in 2021, I believe the transmission, engine w/power steering was around $22k with the PF4 EFI induction. Not sure what that equates to in today's dollars. My engine was built by a local engine builder close to where I live.

I’m in the process of weeding through several engine builders locally.
Sourcing a crate setup out of the USA is simply too expensive with the exchange rate for us up here.
It’s a learning curve.
AI is proving to be a powerful tool for analyzing a proposed build sheet. Not sure if anyone else here uses it but I use AI for increasing amounts of data analysis. Saves hours of Googling

[ProfessorB]

It is coming time to select a new motor and tranny package and I was hoping for some feedback on this decision process.
For starters I had to buy a runner due to time and resources in case anyone is wondering why I didn’t just build a car….trust me I would have loved to and perhaps at some point after retirement I may do so, but buying a runner was my best bet.
My cars a 2012 mk4 completed in 2018 with a “freshen’d up” 302/T5. Totally built on a budget. Based on findings I am sure the freshen’d up comment is extremely loose. It’s clean but that’s about it.
There are several things done not quite right from the braking system to the cooling system and I am looking to make a decision on whether to go 347/TKX or 351w-based 427/TKX while I drop the rearend and change gears and convert the rear to disc.
I have a FFR radiator, Breeze shroud (upper and lower), Breeze rad mounts (upper and lower) and a Flexlite Lowboy fan waiting to go in.

I have spoken to FFR who confirmed both motor options will work in my chassis without modification with the exception of the headers in the 427 application. They said the headers would need to be swapped out too along with an upgraded fuel system?

To my understanding this will work but hoping you guys can connect dots I am undoubtedly missing along with things to consider

Thanks in advance

Quote: "But buying a runner was my best bet"
.
That is absolutely TRUE! It is sad, it is ironic, but it is true. Building a car has become expensive....ESPECIALLY the paint and body work. In my own case, I could build the car competently but NOT the body work. I was lucky, I looked for a while and found a low mileage well-built Mark II with a 427W and TKX. Beautiful paint and all the upgrades I wanted with none of the upgrades I didn't. Ironically, it would have cost me twice as much to build it as I paid for it. Of course there is a downside to it. Firstly, I don't know the car inside out. I have to acclimate myself to the car as I address issues whenever they arrise. And also, I don't have quite that feeling of pride and joy and satisfaction that comes with building your own from the ground up. But the "sum of the parts" is more than the value of the whole. I just could not afford my car if I had to build it. Irionic, to say the least.

[Doc76]

Quote: "But buying a runner was my best bet"
.
That is absolutely TRUE! It is sad, it is ironic, but it is true. Building a car has become expensive....ESPECIALLY the paint and body work. In my own case, I could build the car competently but NOT the body work. I was lucky, I looked for a while and found a low mileage well-built Mark II with a 427W and TKX. Beautiful paint and all the upgrades I wanted with none of the upgrades I didn't. Ironically, it would have cost me twice as much to build it as I paid for it. Of course there is a downside to it. Firstly, I don't know the car inside out. I have to acclimate myself to the car as I address issues whenever they arrise. And also, I don't have quite that feeling of pride and joy and satisfaction that comes with building your own from the ground up. But the "sum of the parts" is more than the value of the whole. I just could not afford my car if I had to build it. Irionic, to say the least.

Yes I did the math over and over and it was crazy that I could buy the car for the price of the parts.
Now yes, there are a lot of other things to consider but I mean for a person on limited time, resources, etc, it really only makes sense to buy a runner if you can find the right one.
As I said, I’m sure after retirement I’ll build one but that’s 10-15 years away.