• Welcome Visitor! Please take a few seconds and Register for our forum. Even if you don't want to post, you can still 'Like' and react to posts.

4.0 OHV suggestions needed for MAF upgrade


VonRicky

Active Member
Joined
Dec 24, 2023
Messages
36
City
Delta, B.C.
Vehicle Year
1991
Transmission
Manual
Hello all,

Just had a 4.0 OHV built with basically 'the works' of what is still commonly available for parts. Morana high comp pistons, stage 2 ported heads, +1mm oversize valves, 422 ground cam from Delta Camshafts, JBA headers I had Cerakoted, BBK 66mm TB, high flow oil pump, I have the crank and a new set of Rockers and arms Nitride finished and made the aluminum sleeves for the rocker arms and on and on...I can't remember it all tbh but it's good.

Anyways, my question is where, or who, makes an oversize MAF ? I got some rebut 19lb injectors and may upsize those depending on the engine and how it runs once broken in. I work in manufacturing and have no problem fabbing stuff up but have no idea where to start other than maybe something from a Mustang maybe...?

I'm an old VW/ Porsche guys so this is a whole new platform for me but I would love to learn from the crowd here. I have already had a few very good interactions and look forward to many more.

Thank you for any and all input you guys can give on this question,

Leigh
 
What are your planned computer modifications? You might not be able to realize your engine's full potential with the stock computer. The computer may not be happy at all and it might not run very well if you have a choppy cam in it.
 
Not sure for now. I was going to see how the initial run goes and if something like MS is needed go from there.

Any suggestions for that ? I see the was something called a Bama Chip back in the day but hours of internetting comes up with nothing. .

Leigh
 
I'm sorry, it was a 410 cam I ordered. Didn't want the 422 because it was a bit lumpy I was told.

It's been a year since I got it and that had slipped out of the grey matter in me head. Sucks getting old.


Leigh
 
There were (maybe still are) tuned maf sensors for injector size and other mods. I've gotta ask why though? I see all your mods and understand the want but I'm pushing 5 to 6 psi boost through the stock 50ish mm maf with no issues, I'm also running a 5.0 explorer throttle body, headers, and a very free flowing exhaust and intake. As long as the sensor isn't pegging and you're not drawing a vacuum at wide open throttle it's not really necessary. The 95 up trucks have even bigger sensors than that, and you can source even bigger sensors (I have an 80mm from a lincoln sitting on a shelf).
The correct way to add injectors is to tune the computer through the use of a piggyback module (tweecer or the now defunct moates) or in later years you can tune the computer directly but I'm not sure who supports that.
 
whew!!!....that is alot of money and work for so little power. but if its being rebuilt anyway i can see a guy going all out as well.

as said above, definitely better to push air through these things so you dont have to do that.


first thing is to just try it and see what happens. is it a full 91 system? does it have a cam sensor and sefi or is it bank fire?


idle could be a bit of a problem, but if it isnt stalling i dont see it running out of fuel...most of these systems hold 5 psi of boost.
 
whew!!!....that is alot of money and work for so little power. but if its being rebuilt anyway i can see a guy going all out as well.

as said above, definitely better to push air through these things so you dont have to do that.


first thing is to just try it and see what happens. is it a full 91 system? does it have a cam sensor and sefi or is it bank fire?


idle could be a bit of a problem, but if it isnt stalling i dont see it running out of fuel...most of these systems hold 5 psi of boost.

5-6 psi here, stock tune and injectors, afr is at the high side of acceptable under high load and rpm (13.1 ish). Stock fuel pump in mine had trouble keeping up initially but the larger replacement pump has no issues.
 
Thank you for the replies guys. Yeah it's money but I figured while it's out and if I'm paying for the machine work and gaskets etc anyways then why not. I ported the heads myself (machinist and old car dude) and got them for a steal and the other parts weren't much more than rebuilt stuff.

I figure this will be the one and only time I'll need to do it ,old thing will outlast me now so....

Leigh
 
it will make more power with less boost and drive pressure.... win win.
 
It isn't boosted..yet. I have a couple other turbo cars for fun and games, this is for my kids to learn to drive on.

Now you have me thinking though, thanks, thanks alot, haha

Leigh
 

Sponsored Ad


Sponsored Ad

TRS Events

Member & Vendor Upgrades

For a small yearly donation, you can support this forum and receive a 'Supporting Member' banner, or become a 'Supporting Vendor' and promote your products here. Click the banner to find out how.

Recently Featured

Want to see your truck here? Share your photos and details in the forum.

Ranger Adventure Video

TRS Merchandise

Follow TRS On Instagram

TRS Sponsors


Sponsored Ad


Sponsored Ad


Amazon Deals

Sponsored Ad

Back
Top