Hello from Ohio!

[Nasty Nate]

Hi everyone,

I'll be putting an LB4 into an FC Rx7 linked to an LT1 T56. I want to be in the 500whp area, but need to keep the power band very broad. I was thinking maybe a PT61, PT66, or GT40 54 trim.

I have a few questions:

Are there any reliable credible sources that have build books?

What are some of the common weak points in the LB4?

Thanks,

Nate

 

[dgoodhue]

Re: Hello from Ohio!

I'll be putting an LB4 into an FC Rx7 linked to an LT1 T56. I want to be in the 500whp area, but need to keep the power band very broad. I was thinking maybe a PT61, PT66, or GT40 54 trim.

I am going to assume your going to use the stock block (ie not a bowtie block) and a stock crank (ie not spend $2500+ on a Billet Crank). I would use a decent sized cam comp cam 412 or 415, with a good set of heads (vortecs) and a ball bearing turbo. 61 might get you 500rwhp, I know the PT67 will do. I assume you want something with a broad power band for the manual transmision, that is why I recommended the ball bearing turbo's for quicker spool.. In general when compared to high strung imports (or other small displacement motors), the 4.3 generally doesn't have suck peaky hp curve.

I would imagine a RX7 will have its fair share of traction issue with 500rwhp. One thing about our motor is they make a ton of torque. A 500rwhp will have upwards of 700 ft-lb at the wheel. You may want to consider that when making your choice.

What are some of the common weak points in the LB4?

All the stock parts.

 

[cds00bsmg]

Re: Hello from Ohio!

Hows it going man? Im in eastern ohio. Had a few RX-7s back in the day, but retained the rotary motor in them. Keep us posted on your swap with plenty of photos.

Chris-