Cosworth power blocks
 

Anyone have them in the tristate area with a AT?

Worth it if I am already at stage 2 catless UEL header? I have no plans of doing FI for this daily driver.

Any thoughts? And yes I read the thread on here which was mostly positive.

You mean Crawford? I didn't know Cosworth made power blocks

I suggest using Google to search this site.

There are numerous threads you can read here discussing this product. Participate in one of them as opposed to restarting a conversation that's already been had :)

Give this Google search a go: "site: www.ft86club.com crawford power blocks"

Also wanted to know if someone nearby has them, hence my first question and why it’s here in tristate.

And yes Crawford, my bad.

Ok - I have a set of Crawford blocks sitting around waiting for install sometime this summer. Might end up being this fall though as I'm going on a long mid July to mid Aug - but if you end up waiting a bit I'll have mine installed eventually. Also have a custom tune with large diameter 4-1 EL headers, so I'll probably end up doing some tweaking with that to optimize the blocks. I also run gas as E85 is too much of a pain to get here in CT (I live in Westport). Will let you know when I get around to putting them on.

"I have no plans of doing FI for this daily driver. "






This phrase always triggers me.


If you're looking to get a bit more punch in the lower rpm, since the blocks shift the power band, you should look into doing a 4.88 gearing swap. I recently did it and it peps the car up a lot.

Thanks for the responses. I will look into the gearing. Although that is likely more expensive but it sounds like it might be worth it.

Do both + good header & custom tune. Probably biggest bang/buck for this car outside of FI.

Ok. So after some research on the 4.88 drive I decided against it. Highway gas mileage takes a hit and I have a 78 mile round trip commute and I like my 33mpg. This car really is a daily driver.

Anyone else out there with an opinion on the Crawford blocks?

your MPG is going to suffer from the power blocks as well. Any edit to how the car came out of the factory will lower your MPG.

I kinda like mine. Fuel mileage is tune related. On e85 I rarely need to run past 5k rpms.

It's what I did on my 6MT. Have GruppeS UEL's, Tune and went with 4.56.
The gearing shifts the powerband close to where it should be. I'm happy I did the gearing, if I had to do it again I would probably look at the 4.88. If you want the best bang for the buck (i.e. tight budget), check out the scrap yards for a 2017+ manual, they have the 4.30 gearing.

I got a stage 1 tune and my mpg jumped a couple. I can pretty easily cruise at 33-35 now and the car's happy spot went from ~72 to 75. I'm wearing down what's left of my winter tires so that's with sticky rubber on warm pavement, I am really curious what it can do with more appropriate shoes but my summer tires are completely worn out so just gonna run these until they're dead too.

That hilariously untrue, that's dictated by how your tune handles fueling tables, AFR and load tables. Driving comparatively, I can get the same MPG with the Stage 2 UEL 93 octane tune as with the stock tune with stock UEL. I've made considerable tune edits to my 93 tunes to achieve this without loss of power, of course when I'm flooring it all the time the 93 tune will do worse than flooring it with the stock uels and tune, obviously the trade off for more power.

stock factory tune for a stock car is the most optimal tune in terms of MPG/POWER am I not correct?


Unless you're telling me adding more power throughout the band is going to improve your mpgs

Not really - factory tune is usually a compromise with large safety margins built in to ensure reliability with a variety of fuel qualities, environments, and usage conditions.

Specifically, aftermarket tune gains mostly come from optimization of timing advance and fuel mixture. Factory tunes usually run slightly richer than what's optimal for power, and less timing advance than what's optimal for power - both will ensure somewhat cooler cylinder temps, slightly lower cylinder pressures, and more protection against knock. Aftermarket tunes push AF ratios & timing advance curves closer to 'optimal for power'. But more optimal AF ratios & timing advance also equals better MPG. This is oversimplifying things a bit but in general optimized factory tunes should return better power AND MPG while sacrificing some margin for knock/reliability in less than ideal fuel conditions.

ahh I see. Thanks for the explanation!

@bfrank1972 took the words right off my keyboard :lol:



In a way you are correct:

The stock tune is optimized for the best timing, and AFR for the stock header and air filter. Its also covers a "wider range" of fuel types from 87 (worst case against owners manual recommendation)-93 (best case but is still held back). They also have been data-logged and proven to run unnecessarily rich in most cases, thats why stage 1 tunes are showing better MPG and power than stock in most cases. In a sense we trade the reliability and convenience of perfect performance in all conditions and fuel types for more specific fuel.

For running a turbo of course you can't compete with NA MPG numbers as you need to add fueling and timing to compete with higher density of air.
For me and you running e85 as well there's no way we can ever get the same MPG as stock because e85 is 15-27 percent less efficient due to the fuel having less energy.

Its pretty complex but OEM tunes leave a lot on the table as far as power and efficiency is concerned on most vehicles.