Does anyone have any flow numbers on the gm lt4 heads?

 

I got these numbers from another site
listed from .1 to .6 lift
intake- 61,117,174,220,242,232
exhaust-52,100,140,167,184,192
actualy now that I think about it, these were the flow numbers for the edelbrock lt1 heads. the flow numbers were almost mirror images though so you can consider this the lt4 port flow

 

I wonder what an ideal cam would be for stock LT4 heads...

 

QUOTE]Originally posted by FacelessZ
I wonder what an ideal cam would be for stock LT4 heads... [/QUOTE]

That's a good question, I'd like some input on that myself. I can tell you that for streetability, emissions, and a close to stock idle the Hotcam is a good choice. With just the LT4 heads/intake and hotcam, I've seen plenty of otherwise stock LT4s make 330-340RWHP. However, I think if I were going to do a cam I'd probably go with the 230/236 as I've seen a lot of people that really love it and I don't have to worry about emissions.

 

Actual flow data obtained for oem as cast LT4 heads are as follows:

.10 - .70 Int. 65-135-175-209-222-222-224
.10 - .70 Exh. 48- 97-124-143-166-170-171

I consider the bench used, to be one of the more accurate (and uninflated) in the country.

 

im sure ill be the first of many to question those numbers....mine flowed 248 with only a 2.02 valve..nothing else touched...L98 vette heads flowed right around 200 cfm the LT1 were about 20 more and the LT4's were 25-30 more then LT1's...im gonna have to say that those are LT1 head numbers

 

Those numbers look more like those from an iron LT1 head... which do flow a little better than the aluminum ones....which flow around 205-210 peak.

Most of the stock LT4 numbers i've seen range around 240cfm peak. If i can find the sheets later on i'll post them.

 

i almost bought a new pair of lt4 heads, but with how much they were it was a waste, i'd rather have my lt1 alum. heads p&p'ed and be able to afford new rr's and springs and they would flow like 20 cfm over the lt4's


then there was used lt4 heads that i was taking a look at but they were low miles he said, wanted like $1000 for the pair.. i still dont think it's worth it =/..

 

Not sure I understand why. Although just a wee bit more conservative, (the LT1 #s) they are inline with numbers posted, on this forum, by a respected porter. Those #s very virtually unchallenged, which is understandable, I respect his reported #s as well.

...I'm gonna have to say that those are LT1 head numbers.

First off, you don't 'have to' anything. Second, the heads were heads I gave the porter, to bench flow. With the numerous LT4 related info I've posted, both here and in 'advanced' section, you'd figure I would know the difference between LT1 and 4 heads.

I agree. Unmolested LT1 iron and LT4 heads flow similar #s.

Again, these are actual #s I obtained, not from questionable internet sources. To repeat sentence from earlier post; "I consider the bench used, to be one of the more accurate (and uninflated) in the country." This porter helped test prototype software. Software now used and supplied by Superflo, with their flow benches. The developer, of this software, had interesting comments, regarding flow #s, (for the same mule heads) from known and respected porters around the country. I'm confident of the accuracy, of the #s I've posted.

It would be fair, to also post something for a set of LT1 (alum) heads as well, for comparo, from the same bench.

@ .60 lift....197 int. and 161 exh.